abstract book of 2012 symposium on piezoelectricity...

Abstract book of 2012 Symposium on Piezoelectricity, Acoustic Waves, and Device Applications Nov. 23-25, 2012

2012 年全国压电和声波理论及器件应用研讨会

The 2012 Symposium on Piezoelectricity, Acoustic Waves and Device Applications

摘要集

Abstract Book

2012 年 11 月 23-25 日

November 23rd

-25th

, 2012

中国上海

Shanghai, China

会议承办：上海交通大学

发起组织：

IEEE UFFC 分会

中国声学学会

中国力学学会

会议协办组织和单位：宁波大学

Conference Hosting:

Shanghai Jiao Tong University

Sponsoring Organizations:

IEEE UFFC

The Acoustic Society of China

The Chinese Society of Theoretical and Applied Mechanics

Conference Co-Organizing:

Ningbo University

AbstractAbstractAbstractAbstract bookbookbookbook ofofofof 2012201220122012 SymposiumSymposiumSymposiumSymposium onononon Piezoelectricity,Piezoelectricity,Piezoelectricity,Piezoelectricity, AcousticAcousticAcousticAcoustic Waves,Waves,Waves,Waves, andandandand DeviceDeviceDeviceDevice ApplicationsApplicationsApplicationsApplications Nov. 23-25, 2012

I

摘要目录/Content/Content/Content/Content1. Paper No.:11

Finite difference time domain analysis of two-dimensional piezoelectric phononic crystals--------------------------------Jiang-bo WEI（1）

2. Paper No.:13

Designing and manufacturing of 1MHZ piezoelectric micro-machined ultrasonic transducer------------------------------Zhi-qun SUO（2）

3. Paper No.: 14

Influence of Co2O3 doped amount on properties of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 lead-free piezoelectric ceramics---Xin-you HUANG（3-4）

4. Paper No.: 15

Research on LFM signals in steel materials----------------------------------------------------------------------------------- Chang-zheng LI（5）

5. Paper No.:16

Properties of miniature X- and Z’-elongated rectangular AT-cut quartz resonators of different sizes--------------------------- S.Y. PAO（6）

6. Paper No.: 17

A brief view of the current state of the development and aging performance of fixed frequency surface acoustic wave (SAW)

oscillators-----------------------------------------------------------------------------------------------------------------------------------C.S. LAM（7）

7. Paper No.: 18

Design of a double-cavities piezoelectric peristaltic pump with finite element method------------------------------------------Liang XU（8）

8. Paper No.: 20

Study on the vibration coupling of a T-type linear ultrasonic motor using longitudinal transducers----------------------Ying-xiang LIU（9）

9. Paper No.:21

Theoretical and experimental study on acoustic subwavelength imaging based on zero dynamic mass--------------------Hai-jing SU（10）

10. Paper No.: 22

Non-symmetric dynamic characteristics of spherically symmetric piezoelectric shell----------------------------------Zu-guang YING（11）

11. Paper No.: 23

Study on a new linear ultrasonic motor with bending PZT elements--------------------------------------------------------Xiao-hui YANG（12）

12. Paper No.:24

A novel rotary piezoelectric motor for aerospace application-----------------------------------------------------------------Xiao-long LU（13）

13. Paper No.: 25

Topology optimization of two-dimensional phononic crystals using FEM and genetic algorithm---------------------Hao-wen DONG（14）

14. Paper No.:26

Spot formation and radial alignment of silver nanowires in a droplet on low-frequency ultrasonic stage----------------Yu-jie ZHOU（15）

15. Paper No.: 27

Pick-and-place of a single nanowire using acoustic streaming------------------------------------------------------------------Hua-qing LI（16）

16. Paper No.: 28

Research on locking device driven by ultrasonic motor for magnetic bearing flywheel------------------------ -------------Xiao-niu LI（17）

17. Paper No.: 29

Piezoelectric frame with non-uniform thickness for vibration energy harvesting ---------------------------------------Song-mao CHEN（18）

18. Paper No.: 30

Experimental investigation of characteristics of the Chladni effect with helical motion -----------------------------------Xiao-bo ZHU（19）

19. Paper No.: 31

3-D manipulations of a single nanowire using uniform micro fiberglass in ultrasonic vibraion -------------------------------Ning LI（20）


II

20. Paper No.: 32

An experimental study on the structure of the internal impact type vibration energy harvester---------------------------------Jing Sun（21）

21. Paper No.: 33

Using PMMA radiation head to improve the transmitting performance of the transducer by finite element method--Hui-sheng LIU（22）

22. Paper No.: 37

Theoretical and experimental study on a new structure free-flooded ring transducer------------------------------------------Xin-ran XU（23）

23. Paper No.: 38

A U-shape transducer array of shallow water multi beam sonar system--------------------------------------------------Zhen-yu ZHENG（24）

24. Paper No.: 39

Analysis of the performance of underwater acoustic parametric array under different input signals-----------------------Lin-lang BAI（25）

25. Paper No.: 41

An analysis of thickness-extension waves of a piezoelectric plate-----------------------------------------------------------De-jin HUANG（26）

26. Paper No.: 42

SH-SAW propagation in a piezoelectric structure with viscoelastic layer-----------------------------------------------------------Jing CUI（27）

27. Paper No.: 43

Green’s function for an electrically permeable crack in thermopiezoelectric materials----------------------------------Ai-bing ZHANG（28）

28. Paper No.: 44

A multi-modes cylindrical piezoelectric rotary motor with a single-vibrator-------------------------------------------------------Bin HE（29）

29. Paper No.: 46

Electroelastic wave propagation in a FGM sandwich circular plate with piezoelectric layers---------------------------Hong-liang DAI（30）

30. Paper No.: 48

Piezoelectrets: polymer foams for transducer applications------------------------------------------------------------------------Peng FANG（31）

31. Paper No.: 49

Effects of a biasing electric field on rayleigh waves in magnetoelectric structures--------------------------------------------Li-li YUAN（32）

32. Paper No.: 50

A study on airborne piezoelectric transducers-------------------------------------------------------------------------------------Sheng ZHOU（33）

33. Paper No.: 51

Large time-bandwidth product ultrasound generation by driving piezoelectric transducer---------------------------------Han ZHANG（34）

34. Paper No.: 52

A thickness-shear mode resonator with a ferroelectric inversion layer---------------------------------------------------Ting-feng MA（35）

35. Paper No.: 53

Self assembly particles using phononic-crystal slabs----------------------------------------------------------------------------------Qian WU（36）

36. Paper No.: 54

Equivalent circuit model with time-varying parameters for a traveling wave ultrasonic motor-----------------------------Wei-jia SHI（37）

37. Paper No.: 55

An efficient higher order zigzag theory for piezoelectric and piezomagnetic composite and sandwich beams--------------Long ZOU（38）

38. Paper No.: 56

Exact analysis of the dynamic properties of 2-2 cement based piezoelectric actuator considering poling layer

effect-------------------------------------------------------------------------------------------------------------------------------- Tao-tao ZHANG（39）

39. Paper No.: 57

Research of the influence on magnetoelectric effect by the curvature of composite cylinder--------------------------Hui-ming WANG（40）


III

40. Paper No.: 58

Structural dynamics design and optimize of axial/radial coupling non-contact piezoelectric ultrasonic motor with a spherical

rotor---------------------------------------------------------------------------------------------------------------------------------Jun-shan WANG（41）

41. Paper No.: 59

Influence of initial stresses on resonance properties of FBARs--------------------------------------------------------------De-jin HUANG (42)

42. Paper No.: 60

Study on the fiber sensor PGC modulation based on PZT ------------------------------------------------------------------De-sheng CHEN (43)

43. Paper No.: 62

Research on driving technology for a four-phase piezoelectric linear motor--------------------------------------------------Guan-yin YU(44)

44. Paper No.: 64

Design and analysis of a longitudinal piezoelectric vibration exciter-------------------------------------------------------------Zhi-qiang LI(45)

45. Paper No.: 65

DOA estimation of the moving targets in shallow water based on normal-mode theory and vector optimization

beamforming------------------------------------------------------------------------------------------------------------------------------Nan-song LI(46)

46. Paper No.: 68

The magnetoelectric effects of Terfenol-D/PZT/Terfenol-D laminated structures-------------------------------------------------Long XIA(47)

47. Paper No.: 69

Research of the S-type linear piezoelectric motor------------------------------------------------------------------------------Sheng ZHANG（48）

48. Paper No.: 70

Study on design and experimental of a piezoelectric linear motor using double driving feet--------------------------------Wei-hua LIU（49）

49. Paper No.: 71

Simulation of seismic wave propagation in shallow water environments---------------------------------------------------------------Li LI（50）

50. Paper No.: 72

Piezomagnetic love waves on orthortropic piezoelectric half-spaces------------------------------------------------------Yan-ping KONG（51）

51. Paper No.: 73

Rayleigh waves in a piezomagnetic/piezoelectric structure--------------------------------------------------------------------Qing-guo XIA（52）

52. Paper No.: 76

Band gaps calculation of scalar waves in two-dimensional phononic crystals with generalized multipole technique (GMT)

---------------------------------------------------------------------------------------------------------------------------------------------Zhi-jie SHI（53）

53. Paper No.: 77

Numerical analysis on the sandwich dipole logging transducer with various loads--------------------------------------Qiu-ying CHEN（54）

54. Paper No.: 78

A study on performance of saw devices based on AlN/Diamond---------------------------------------------------------Hua-lei WANG（55-56）

55. Paper No.: 80

Fabrication of bulk acoustic wave resonator based onAlN thin film---------------------------------------------------------------Jie YANG（57）

56. Paper No.: 81

Amethod for improving the electrical limit of Langevin ultrasonic transducer-----------------------------------------Zhao-feng LIANG（58）

57. Paper No.: 83

A dispersive nonlocal model for shear-wave propagation in laminated composite with periodic structure-----------H. Brito-Santana（59）

58. Paper No.: 84

Propagation of nonlinear longitudinal waves in an elastic rod----------------------------------------------------------------Rong-xing WU（60）


IV

59. Paper No.: 85

Mechanism on energy transmission control in beams based on the piezoelectric transducers------------------------------Tian-zhu XU（61）

60. Paper No.: 87

A modified synchronized switch for multi-frequency piezoelectric energy harvesting based on voltage switching threshold

--------------------------------------------------------------------------------------------------------------------------------------------Tian-li LUO（62）

61. Paper No.: 88

Deducing and verifying the frequency equation set of dual-frequency piezoelectric transducer--------------------------------Jia-he FU（63）

62. Paper No.: 89

Active structural acoustic control of a thin shell using piezoelectric material------------------------------------------------------Li-jun LI（64）

63. Paper No.: 90

A microreactor using surface acoustic wave as an energy source-------------------------------------------------------------------Yan ZHA（65）

64. Paper No.: 91

Influence of barium content on the properties and structure of low temperature sintered BCZT lead-free piezoelectric

ceramics-----------------------------------------------------------------------------------------------------------------------------Chun-hua GAO（66）

65. Paper No.: 92

Study on signal crystal photo-elastic modulator based on lithium niobate piezoelectric and photo-elastic effect-----You-hua CHEN（67）

66. Paper No.: 94

Correction factors for Mindlin plate equations with the consideration of stiffness and mass effects of electrodes for SC-cut quartz

crystal plates--------------------------------------------------------------------------------------------------------------------------------Ji WANG（68）

67. Paper No.: 95

Free vibration of fixed supported and multilayered magneto-electro-elastic plates----------------------------------------------Li-bo XIN（69）

68. Paper No.: 96

SH waves in functionally graded piezoelectric-piezomagnetic material structures--------------------------------------Ruo-meng TIAN（70）

69. Paper No.: 97

The multicoupled magnetoelectric effect in three-phase Tb1-xDyxFe2/Pb(Zr1-xTix)O3/NdFeB bimorph laminates

--------------------------------------------------------------------------------------------------------------------------------------Zeng-ping XING（71）

70. Paper No.: 98

Reverberation-ray analysis of timoshenko beam on elastic foundation with arbitrary dynamic loadings---------------Ji-qing JIANG（72）

71. Paper No.: 103

2D and 3D Green’s functions for pyroelectric media------------------------------------------------------------------------Peng-fei HOU（73）

72. Paper No.: 104

Advances in design, growth and application of piezoelectric crystals with langasite structure-----------------------Yan-qing ZHENG（74）

73. Paper No.: 105

Resonant giant magnetoelectric effect of piezoelectric/magnet composites--------------------------------------------------------Kai XU（75）

74. Paper No.: 107

A CAN method to image the quantitative bonding strength at the bonded solid-solid interface---------------------------Jian-jun CHEN(76)

75. Paper No.: 108

Analysis and development of the plate-attached cylindrical rotary-linear ultrasonic motors----------------------------Ting-hai CHENG(77)

76. Paper No.: 109

An analysis of frequency-temperature relations of a quartz crystal tuning fork----------------------------------------------------Ji WANG(78)

77. Paper No.: 110

Analyses on dispersion and excitation features of symmetric guided waves in a fluid-filled cylindrical shell --------------Xi-qiang LI(79)

AbstractAbstractAbstractAbstract bookbookbookbook ofofofof 2012201220122012 SymposiumSymposiumSymposiumSymposium onononon Piezoelectricity,Piezoelectricity,Piezoelectricity,Piezoelectricity,AcousticAcousticAcousticAcoustic Waves,Waves,Waves,Waves, andandandand DeviceDeviceDeviceDeviceApplicationsApplicationsApplicationsApplications Nov. 23-25, 2012

V

78. Paper No.: 111

Dipole source mismatch and its effects on sonic logging----------------------------------------------------------------------------Hao CHEN(80)

79. Paper No.: 112

Measurement of the acoustical field characteristic of phased array transducer---------------------------------------------Chun-guang XU(81)

80. Paper No.: 113

Growth habits of doped and undoped langatate single crystals--------------------------------------------------------------------Xiao-niu TU(82)

81. Paper No.: 115

Phase field simulation on the nonlinear fracture of ferroelectric materials---------------------------------------------------Hong-liang GU(83)

82. Paper No.: 116

Composite structure piezoelectric energy harvester using single crystal 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3-------Chun-Dong XU(84-85)

83. Paper No.: 117

Propagation of love waves in a thin functionally graded piezoelectric layer imperfectly bonded to a piezomagnetic substrate

--------------------------------------------------------------------------------------------------------------------------------------------------Dong YE(86)

84. Paper No.: 118

Temperature dependence of electro-elastic properties of yttrium calcium pxyborate single crystals------------------------Fa-peng YU(87)

85. Paper No.: 119

Mode coupling in PIMNT single-crystal rectangular beams and its application in ultrasonic linear arrays------------------Wei WANG(88)

86. Paper No.: 120

Theory on the laser excited wave propagation in a single piezoelectric plate under a bias electric field ---------------------Gen CHEN(89)

87. Paper No.: 121

Fast algorithm for the method of fundamental solution subjected to multi-symmetry problems --------------------------------Li-na WU(90)

88. Paper No.: 122

Electrical and stress fields of the surface electrodes on the electrostrictive material---------------------------------------------Hai-e WEI(91)

89. Paper No.: 123

Theory on the air-couple wave propagation in layered composite materials with laminate defect --------------------------Song LING(92)

90. Paper No.: 124

Inversion of shear velocity profile in a cased borehole-------------------------------------------------------------------------Ming-ming MA(93)

91. Paper No.: 125

The analytical solution and numerical simulation of the P-SV wave propagation in the piezoelectric laminate-----------------Lei LIU(94)

92. Paper No.: 126

Three-dimensional vibration analysis of split electrode vibrator using finite element method--------------------------------------Lin FU(95)

93. Paper No.: 127

Solid elements with surface-bonded piezoelectric patch-------------------------------------------------------------------------Rong-qiao XU(96)

94. Paper No.: 128

Depth profiling of coating by laser ultrasonic technique----------------------------------------------------------------------Xue-hang SONG(97)

95. Paper No.: 129

Analysis of piezoelectric laminated plates using the layerwise plate theory and radial basis function collocation method-----Yu YIN(98)

96. Paper No.: 131

Preparation and piezoelectric analysis of the multilayer films for FBAR--------------------------------------------------------------Lin SU(99)

97. Paper No.: 133

Study on a high sensitivity tangential polarized acoustic-pressure hydrophone------------------------------------------------Hu ZHANG(100)


VI

98. Paper No.: 134

Study on a high sensitivity and strong anti-jamming co-vibrating vector sensor----------------------------------------------Hu ZHANG(101)

99. Paper No.: 135

The measurement of elastic constants of quartz crystal by resonant ultrasound spectroscopy----------------------------------Ji WANG(102)

100. Paper No.: 136

Magneto-electro-elastic laminated plates with an elliptical hole subjected to out-of-plane bending moments--------Xiang-hua DAI(103)

101. Paper No.: 137

The anti-plane vibration of quartz plate with an additional partial non-uniform mass layer---------------------------------------Peng LI(104)

102. Paper No.: 138

Wave propagation in a layered magneto-electric hollow cylinder ----------------------------------------------------------Yong-dong PAN(105)

103. Paper No.: 139

First principles study on the flexoelectric coefficients of barium titanate------------------------------------------------------Tao XU(106-107)

104. Paper No.: 140

Effects of elastic matrix on longitudinal wave propagation in nano scale plate-----------------------------------------------Yi-ze WANG(108)

105. Paper No.: 141

The finite element analysis of ultrasonic reflection method used in acoustic logging--------------------------------------Zhi-feng SUN(109)

106. Paper No.: 145

Two-dimensional Mindlin plate equations of vibrations of circular elastic plates------------------------------------------------Ji WANG(110)

107. Paper No.: 146

Frequency-temperature analysis of thickness-shear vibrations of SC-cut plates with the first-order Mindlin plate equations

------------------------------------------------------------------------------------------------------------------------------------------------Ji WANG(111)

108. Paper No.: 148

Design and analysis of a self-sensing smart tool intergrated piezoelectric films for cutting force monitoring in ultra-precision

machining-----------------------------------------------------------------------------------------------------------------------------Cai-wei XIAO(112)

109. Paper No.: 149

Thickness-shear and thickness-twist modes in an oblate elliptical ceramic cylinder and energy trapping in contoured acoustic wave

resonators--------------------------------------------------------------------------------------------------------------------------------Hui-jing HE(113)

110. Paper No.: 151

Overtone-mode limits on AT-cut fundamental crystal resonator, through twice plating method-----------------------Lin-lin ZHANG(114)

111. Paper No.: 152

Pressure-induced enhancement of piezoelectricity of quartz-like single crystals-----------------------------------------Kai-nan XIONG(115)

112. Paper No.: 153

Scattering problem of the interface circular cavity in piezoelectric media-----------------------------------------------------------Lei LIU(116)

113. Paper No.: 157

Energy harvesting using a cantilever structure based on the shear mode of 0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 single crystal

---------------------------------------------------------------------------------------------------------------------------------------------Zhu LIANG(117)

114. Paper No.: 158

Acoustic property of slightly compressible porous media and underwater structure-borne noise reduction--------------------Bo QIN(118)

115. Paper No.: 159

UHF SAW-based RFID with integrated antenna---------------------------------------------------------------------------------------Duo LIU(119)

116. Paper No.: 160

Influence of crack orientation and boundary conditions on fracture behavior of piezoelectric matreials----------------Cui-ying FAN(120)


VII

117. Paper No.: 162

Ultrahigh temperature piezoelectric accelerometer using langatate single crystals-----------------------------------------Pan GAO(121-122)

118. Paper No.: 163

Design of temperature sensor array in smart electric grid based on SAW resonators-----------------------------------------Yu-lin HAN(123)

119. Paper No.: 164

The boundary conditions of the fixed end of piezoelectric cantilever beams----------------------------------------------Lian-zhi YANG(124)

120. Paper No.: 165

A novel approach to simulate low-loss surface acoustic wave devices using dispersive COM parameters----------------Hao WANG(125)

121. Paper No.: 166

Propagation of Bleustein-Gulyaev wave in a piezoelectric crystal in contact with viscous solution ---------------------Feng-lin GUO(126)

122. Paper No.: 169

High-efficient broadband lamb wave rectifier based on a one-dimensional graded phononic crystal slabs-------------Jiu-jiu CHEN(127)

123. Paper No.: 171

Computational analysis on the drag forces of oil-pipelines in drilling across yellow river-------------------------------------Shi-qi XU(128)

124. Paper No.: 172

The study of high-frequency broad-band underwater transducers---------------------------------------------------------------Kai ZHANG(129)

125. Paper No.: 174

Damage identification in a steel frame using electro-mechanical impedance signatures--------------------------------------Wei WANG(130)

126. Paper No.: 175

A piezoelectric unimorph power harvester operating with coupled extension and flexure modes-----------------------Zi-yang LIAN(131)

127. Paper No.: 177

Propagation of SH surface waves in a semi-infinite magneto-electro-elastic layered periodic structures---------------------Yu PANG(132)128. Paper No.: 178Effects of boundary-layer thickness on aero-acoustics characteristics of subsonic shallow cavity flow-------------Dang-guo YANG(133)129. Paper No.: 180Investigation on parameters influencing synthetic-jet for active flow control--------------------------------------------------Yi ZHANG(134)

130. Paper No.: 181

Investigation on calibration methods of thermal mems shear stress sensor array------------------------------------------Jin-min LIANG(135)

131. Paper No.: 182Dynamical characteristics research on the squeezed film damper stiffness rotor---------------------------------------Rui-hua ZHANG (136)132. Paper No.: 185

Application of piezoelectric material in the active vibration control of conical shell structures---------------------------Feng-ming LI(137)

AuthorAuthorAuthorAuthor IndexIndexIndexIndex------------------------------------------------------------------------------------------------------------------------------------------(138)


- 1 -

PaperPaperPaperPaper No.:No.:No.:No.: 11111111

FINITEFINITEFINITEFINITE DIFFERENCEDIFFERENCEDIFFERENCEDIFFERENCE TIMETIMETIMETIMEDOMAINDOMAINDOMAINDOMAINANALYSISANALYSISANALYSISANALYSIS OFOFOFOFTWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC

PHONONICPHONONICPHONONICPHONONIC CRYSTALSCRYSTALSCRYSTALSCRYSTALS

Jiang-bo WEI1*, Hong-lang LI2, Yong LIANG2, Shi-tang HE2

1Department of Electronic Science and Technology, Beijing Institute of Technology, Beijing 1000812Micro-electromechanical systems, Institute of acoustics, Chinese academy of sciences, Beijing100190

* Corresponding author, E-mail: [email protected]; Tel.: 010-82547805

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePhononic crystals (PCs) have a fruitful and promising band gaps, In which Surface Acoustic Wave (SAW) propagating is prohibited. Several numericalmethods have already been developed and applied to the analysis of piezoelectric PCs, most of them have various disadvantages, as the methods cannotcalculate the transmission characteristic of the limited structure or cannot provide the propagation process for SAW over time. The finite-differencetime-domain（FDTD）technique solving these problems is adopted to analyze the piezoelectric characteristics of PCs.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAs an example, the PCs are composed of a square array of parallel cylindrical aluminum of radius R placed on a 1280YXLiNbO3 substrate. The latticeparameter is 10um. The mechanical-electrical coupling has been took into account. Bloch-Floqet periodic boundary conditions are applied at theboundaries of the unit cells. Moreover the perfectlymatchinglayers (PMLs)is imposed to the non-reflecting boundary conditions. Propagation in the PCsis studies by direct generation and detection of SAW using Interdigital transducers(IDT’s).

ResultsResultsResultsResultsThe calculative band gap of aluminum / LiNbO3 structures is extends from 295 to 350MHZ.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe effects discussed of two-dimensional piezoelectric PCs can be potentially used in high-performance SAW filters, notch filter and SAW resonators.

KeywordsKeywordsKeywordsKeywords:::: two-dimensional PCs; piezoelectric; FDTD; SAWAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: The work was supported by the National Natural Science Foundation of China (No. 61071054).

mailto:[email protected]


- 2 -

PaperPaperPaperPaper No.:No.:No.:No.:13131313

DESIGNINGDESIGNINGDESIGNINGDESIGNINGANDANDANDANDMANUFACTURINGMANUFACTURINGMANUFACTURINGMANUFACTURINGOFOFOFOF1MHZ1MHZ1MHZ1MHZ PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICMICRO-MACHINEDMICRO-MACHINEDMICRO-MACHINEDMICRO-MACHINED

ULTRASONICULTRASONICULTRASONICULTRASONICTRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCER

Zhi-qun SUO, Zhen-hong HAO, Dong-hai QIAO*Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190

*Corresponding author, E-mail: [email protected];

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePMUT has advantages with smaller volume, lighter weight and more consistency on performance and can be produced into scales. Therefore, it haspositive outlook in application. Hence, the high efficient PMUT and its array became the ultrasonic 3D imaging research focus.The ultrasonic imaging is the most active branch of the ultrasonics. Now the ultrasound B-scan imaging has become an important medical diagnosticmethod. B-ultrasound is a two-dimensional imaging with one-dimensional array while the ultrasonic imaging will develop into 3D imaging, the same asother imaging methods development. Ultrasonic 3D imaging is rapidly becoming the new development direction of the ultrasonic field. To implement3D imaging, it needs 2D array, which required tens of thousands of ultrasonic PMUT cells with consistency. It will bring huge difficulties with separatePMUT cells and electric circuit. However, currently it can only make little 2D arrays. The solution is to use integrated MEMS, replacing the separatearray with MEMS. In the future, it can even form SOC micro-ultrasound imaging system with micro-ultrasound PMUT arrays, transmitter circuit,receiving circuit, signal processing and controlled circuit integrated in one SOC. It will give the revolutionary change on ultrasound imaging if such aultrasound imaging system can be implemented through MEMS PMUT arrays.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsTo solve the problem of small size, low capacitance and high impedance on PMUT, this paper proposed the PMUT organized by the micro-PMUTarrays; the micro-PMUT were parallel connected with the same resonant frequency. The parallel connected PMUT resonant frequency is the resonantfrequency for each micro PMUT and the PMUT static capacitance is the subtotal of all the parallel connected micro-units’ capacitance while the PMUTimpedance decreased to one Nth of the unit’s impedance, where N is the number of the parallel connected units. Hence, with such designing, the PMUTwill have huge improvement on the performance, compared with single PMUT. When designing in such way, all the parallel connected PMUT shouldbe arrayed as closely as possible, because the organized unit would form a micro-plane array actually. Its emission acoustic field is the overlay of all theparallel connected units. When the frequency is high and the distributed area is wide, the array is directional. Therefore, the spaces between the parallelconnected units should be reduced as much as possible. The directional effect should be reduced as well as raising the PMUT working efficiency. ThePMUT efficiency can be raised by PMUT directivity, index of the impedance and capacitance, the distribution and the amount of the parallel connectedunits, etc. Moreover, it can enlarge PMUT capacitance and reduce the impact PMUT by parasitic capacitance. In addition, the designing can also reducethe PMUT impedance and the energy consumption. This paper employed equilateral hexagon parallel connected micro cells, which can guarantee thesymmetry of the PMUT emission. The amount of the parallel units can increase regularly with the increment of the units on each side of the hexagon.As PMUT is designed in multi-units parallel connected, it is important for PMUT to guarantee the yield and the stability of each unit. The rounddiaphragm has the advantage of evenly distributed and uneasily broken in the production process. Thus, in this paper, the designed parallel connectedmicro PMUT units are all round diaphragm, guaranteeing the yield of the PMUT.ResultsResultsResultsResultsThis paper has designed a new type of high frequency Piezoelectric Micro-machined Ultrasonic Transducer (PMUT) array in multi-units and parallelconnection, based on sacrificial layer technology. It prepared the PMUT whose resonant frequency reached 1 MHz and studied on the process that thereleased sacrificial layer applied on the PMUT preparation. It measured the admittance frequency response curve of the PMUT, whose resonantfrequency was 1.14 MHz, in line with expected result. It implemented the PMUT’s transceiver test. From the test, the receiving sensitivity of the PMUTin 1 MHz was -255 dB (ref 1V/µPa), the acoustic pressure output was 131.2 dB (ref 1µPa•m/V), and the -3 dB band was about 68%.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe 1 MHz PMUT in this paper utilized array structure with multi-units and parallel connection. It has a better receiving sensitivity. The lower voltageresponse is because of the smaller sound emitted area of one single PMUT; the transmitted terminator is lack of supporting facilitates. Besides, thepiezoelectric indicator of ZnO material was often low itself. As a result, further experiment can use PMUT array to transmit, raising the emitted soundpressure. It can also design the matched circular to raise the transmitted efficiency based on the PMUT equivalent circular. In addition, the research canexplore on producing piezoelectric membrane with high piezoelectric indicator, such as PZT to replace ZnO, which will further improve the PMUTtransceiver performance.

KeywordsKeywordsKeywordsKeywords:::: piezoelectric ZnO film; piezoelectric micro-machined ultrasonic transducer (PMUT); micro-electro-mechanical systems (MEMS)



- 3 -


INFLUENCEINFLUENCEINFLUENCEINFLUENCE OFOFOFOFCoCoCoCo2222OOOO3333 DOPEDDOPEDDOPEDDOPEDAMOUNTAMOUNTAMOUNTAMOUNTONONONON PROPERTIESPROPERTIESPROPERTIESPROPERTIES OFOFOFOF (Ba(Ba(Ba(Ba0.850.850.850.85CaCaCaCa0.150.150.150.15)(Zr)(Zr)(Zr)(Zr0.10.10.10.1TiTiTiTi0.90.90.90.9)O)O)O)O3333

LEAD-FREELEAD-FREELEAD-FREELEAD-FREE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC CERAMICSCERAMICSCERAMICSCERAMICS

Xin-you HUANG*, Chun-hua GAO, Zhi-wen ZHU, Li PAN, Zhi-gang CHENSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013,China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric ceramics is a kind of important functional materials which can convert electric energy from mechanical energy. At present, the widespreaduse of piezoelectric ceramics is Pb(Ti,Zr)O3 lead-based piezoelectric ceramic materials. Compared with lead based piezoelectric ceramic materials, thepiezoelectric properties of lead free piezoelectric ceramics is a big gap for piezoelectric properties. But lead free piezoelectric ceramics havepollution-free, without social effects of pollution, advantageous to environmental protection and advantage of environmental compatibility. The studyof lead free piezoelectric ceramics is paid high attention by all countries. In recent years, researcher report successively BaTiO3 piezoelectric ceramicswith high piezoelectric properties and BaTiO3 piezoelectric ceramics was prepared by conventional solid state sintered method and analytical purematerials was used as raw materials. There was little report about the study of influence of Co2O3 doped amount on the properties and structure ofbarium calcium zirconate titanate series lead-free piezoelectric ceramics. In this paper, influence of Co2O3 doped amount on the properties and structureof (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3(BCZT) series lead-free piezoelectric ceramics was studied by conventional solid state method and TiO2 is chemically pureraw materials, other raw materials were analytical pure raw materials. Co2O3 doped modified mechanism of the properties of BCZT lead freepiezoelectric ceramics was investigated.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/Methods(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) lead-free piezoelectric ceramics were prepared using a conventional solid state method. The influence of Co2O3

doped amount on the crystal phase, surface microstructure and properties of the (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) lead-free piezoelectric ceramicswere studied by scanning electron microscope(SEM) and X-ray diffraction(XRD) and other analytical methods. TiO2 was chemically pure rawmaterials, other raw materials were analytical pure raw materials. Lead-free piezoelectric ceramics with high piezoelectric properties was obtained,Co2O3 doped modified mechanism of the properties of BCZT lead free piezoelectric ceramics was investigated.ResultsResultsResultsResultsThe piezoelectric properties was increased for a certain extent when Co2O3 doped , the piezoelectric properties was decreased when Co2O3 dopedamount was too much. The comprehensive performance of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 lead-free piezoelectric ceramics was optimum when Co2O3

doped amount was 0.40wt.% which piezoelectric strain constant(d33) was 171pC/N, relative dielectric constant(εr) was 22400, planarelectromechanical coupling coefficient(kp) was 0.478, dielectric loss was 0.018, electromechanical coupling coefficient of thickness(kt) was 0.041,sintered temperature was 1340.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsPerovskite structure of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 lead-free piezoelectric ceramics did not change when doped with Co2O3, the intensity of diffractionpeaks of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 firstly increased and then decreased,the grain crystal size of ceramics firstly increased and then decreased,the densityof ceramics firstly increased and then decreased when Co2O3 doped amount increased.The microstructure of ceramics was the best when Co2O3 dopedamount was 0.40wt.%. This is also reason for the good piezoelectric properties. The piezoelectric properties(d33, kp, kt) of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3

lead-free piezoelectric ceramics firstly increased and then decreased, the relative dielectric constant(εr) decreased, dielectric loss firstly increased andthen decreased when Co2O3 doped amount increased. Co3+ ion radius is 0.063 nm, It takes A and B tolerance factor(t) are 0.65 and 0.96, respectively.The stabilization perovskite structure could be obtained when 0.8≤t≤1.1. The stabilization perovskite structure could be obtained when Co3+ took theplace of Ti4+. Because Co3+ ion radius（0.063nm）is less than Ti4+ ion radius（0.086nm）, the bigger lattice distortion is produced and electric domainrotation is easy and there are more orientation of electric domain along the direction of the electric field when polarization and Co2O3 doped amountincreased, the piezoelectric properties increased when Co2O3 doped amount increased. At the same time, in order to achieve price equilibrium, oxygenvacancy could be produced when Co3+ took the place of Ti4+. Electric domain rotation is difficult and there are less orientation of electric domain alongthe direction of the electric field when polarization and Co2O3 doped amount increased, the piezoelectric properties decreased when Co2O3 dopedamount increased. In the Co3+ instead of Ti4+ process, when the Co3+ instead of Ti4+ is less amount, produced lattice distortion effect dominates, thepiezoelectric properties increased when Co2O3 doped amount increased. When the Co3+ instead of Ti4+ is more amount, produced oxygen vacancy effectdominates, the piezoelectric properties decreased when Co2O3 doped amount increased. When ceramic density increased, defect reduced, energyconsumption of domain wall motion decreased, dielectric loss decreased. When Co2O3 doped amount was too much, Co3+ can not be completelydissolved in BCZT ceramics, there is a part of impurity phase produced and deposition at grain boundaries, dielectric loss increased. The materialsdoped with Co2O3 are easy to appear ion conductance loss phenomenon and will make the relative dielectric constant decrease and dielectric lossincreased. The comprehensive performance of (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 lead-free piezoelectric ceramics was optimum when Co2O3 doped amount was0.40wt.% which piezoelectric strain constant(d33) was 171pC/N, relative dielectric constant(εr) was 22400, planar electromechanical coupling


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coefficient(kp) was 0.478, dielectric loss was 0.018, electromechanical coupling coefficient of thickness(kt) was 0.041, sintered temperature was1340.

KeywordsKeywordsKeywordsKeywords:::: lead free piezoelectric ceramics; calcium barium zirconate titanate; Co2O3; doped modificationAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: The work was supported by Program of Science and Technology Support of Jiangsu Province (No. BE2008029), Thework was supported by Project of Combination of Producing, Learning and Studying of Guangdong Province and EducationDepartment(No.2011B090400027).


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RESEARCHRESEARCHRESEARCHRESEARCHONONONONLFMLFMLFMLFM SIGNALSSIGNALSSIGNALSSIGNALS ININININ STEELSTEELSTEELSTEELMATERIALSMATERIALSMATERIALSMATERIALS

Chang-zheng LI1,2*, Fang-fang SHI1

1 Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190

2The Yellow River Institute of Hydraulic Research, Zhengzhou 450003


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveLinear frequency modulation (LFM) signal is first used in radar field due to its remarkable properties, such as wide bandwidth, high energy and highsignal-to noise ration. LFM excitation has recently been introduced in medical ultrasonic scanning, and much exciting results were obtained by researchstaffs. However, there is little study aiming to inspect steel materials utilizing coded excitation. LFM signal with large time-bandwidth product can bedesigned theoretically, but the limited bandwidth of a transducer will lead to energy loss. Several coded signals were used to excite transducer，then thereceived signals’ amplitude and spectrum were analyzed. The results show that the amplitude will decrease when the frequency exceed the transducer’sbandwidth(-6dB). In order to investigate the transmitting law in steel materials, signals excited by LFM code were compared to signals excited by shortpulse. It is found that after penetrating steel material with certain thickness the amplitude of LFM wave is higher than short pulse wave. So LFM wavecan help improve the penetrating depth. Through the analysis, it is found that wave at high frequency band attenuates much quickly than wave at lowfrequency band. The results of investigation of the sound field in a steel plate are provided. In addition, the results of measured pressure fielddistributions before and after compression were compared with the recorded signals using short pulse excitation.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe characteristics of waveform and spectrum were analyzed with LFM coded excitation. The SNR of LFM signal at output side will be improved withpulsed compression method. At the same time, the range resolution increase after matched filter. The sound field on the surface of a steel plate wasmeasured using several LFM coded signal exciting. This paper shows the feasibility of inspecting steel material with LFM signals.

ResultsResultsResultsResultsTest results indicate that the transducer’s bandwidth will influence the amplitude of signals with different frequency. The amplitude will decrease if thecorresponding frequency exceeds the transducer’s bandwidth. LFM signal is easily measured than conventional pulse signal after penetrating a longermaterial. The pressure distributions in a steel plate with LFM excitation were presented. The amplitude will increase after compression even there is nomuch difference before compression.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsLFM can be used to inspect steel materials. However, the transducer’s bandwidth should be considered in order to inspire high energy signals. On theother side, the matched filter function should be selected according to the characteristics of the material.

Keywords:Keywords:Keywords:Keywords: LFM; pulse compression; coded excitation; matched filter; steel material inspectedAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: The work was supported by the National Natural Science Foundation of China (No. 11074273). The work was alsosupported by the Central Scientific Research Institute of the public basic scientific research business professional (No. HKY-JBYW-2010-17).



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PROPERTIESPROPERTIESPROPERTIESPROPERTIES OFOFOFOFMINIATUREMINIATUREMINIATUREMINIATUREX-X-X-X-ANDANDANDAND ZZZZ’’’’-ELONGATED-ELONGATED-ELONGATED-ELONGATED RECTANGULARRECTANGULARRECTANGULARRECTANGULARAT-CUTAT-CUTAT-CUTAT-CUT QUARTZQUARTZQUARTZQUARTZ

RESONATORSRESONATORSRESONATORSRESONATORSOFOFOFOFDIFFERENTDIFFERENTDIFFERENTDIFFERENT SIZESSIZESSIZESSIZES

S.Y. PAO1*, Q.Q. PAN1, J.S CHUNG2, W.Y. CHANG1, T. LIN1, M.K. CHAO1, C.S. LAM3

1TXC (Ningbo) Corporation, Ningbo City, Zhejiang Province, China

2TXC Corporation, Ping Cheng City, Taoyuan County, Taiwan

3TXC Technology, Inc., Milpitas, California, USA

* Corresponding Author, E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveRectangular AT-cut quartz resonators were first developed in the early 70s for their small size and ease of manufacture. Many studies were performedon the resonant properties of different aspect ratio of the rectangular plate. Based on the studies, one can deduce the following. When the length of therectangular plate is along the X direction and the width to thickness ratio is small (i.e. DT-cut), the coupling between the thickness-shear (TS) mode andthe face-shear mode is strong. On the other hand, as the length of the rectangular plate is along the Z’ direction and the plate is mounted on the twowidth sides, the TS mode is coupled more strongly with the flexure mode. The studies, though provided valuable information for designers, areconsidered dated as today’s quartz crystal resonators are of much smaller sizes. For example, nowadays a typical 3225 (3.2mm by 2.5mm) 9.8 MHzpackaged quartz crystal still has the blank thickness of about 0.17mm but the blank size is only 2.1mm by 1.5mm. The length-to-thickness and thewidth-to-thickness ratio are both small. The earlier design rules for larger blanks may no longer applicable nowadays.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this study, we present the different properties of beveling process, equivalent series resistance (ESR), temperature curves, temperature hysteresis, andshock resistance due to different X- and Z’-elongated rectangular AT-cut quartz plate of different sizes.

ResultsResultsResultsResultsThe results show the Z’-elongated quartz strip mounted on the two width sides has better performance in temperature hysteresis and shock resistance.And for mode coupling, beveling process, and temperature curve, X- and Z’-elongated rectangular AT-cut quartz plate have their respective properties.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsA quartz resonator designer should consider X- or Z-elongated rectangular crystal plates for different applications and specifications.

KeywordsKeywordsKeywordsKeywords:::: AT-Cut resonator, quartz crystal plate, aspect ratio


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AAAA BRIEFBRIEFBRIEFBRIEFVIEWVIEWVIEWVIEWOFOFOFOFTHETHETHETHECURRENTCURRENTCURRENTCURRENT STATESTATESTATESTATEOFOFOFOFTHETHETHETHEDEVELOPMENTDEVELOPMENTDEVELOPMENTDEVELOPMENTANDANDANDANDAGINGAGINGAGINGAGINGPERFORMANCEPERFORMANCEPERFORMANCEPERFORMANCEOFOFOFOFFIXEDFIXEDFIXEDFIXED FREQUENCYFREQUENCYFREQUENCYFREQUENCYSURFACESURFACESURFACESURFACEACOUSTICACOUSTICACOUSTICACOUSTICWAVEWAVEWAVEWAVE (SAW)(SAW)(SAW)(SAW) OSCILLATORSOSCILLATORSOSCILLATORSOSCILLATORS

C.S. LAM1*, P.Y. SU2, C.H. CHEN2

1TXC Technology, Inc., Milpitas, California, USA

2TXC Corporation, Ping Cheng City, Taoyuan County, Taiwan

*Corresponding Author, E-mail: [email protected]; Tel.: 1-714-721-4348

The recent rapid expansion of fiber-based networking markets fuels the demand for accurate 100~400 MHz crystal oscillators (XOs). High

frequency fundamental (HFF), third overtone (3OT) and inverted mesa (IM) crystal oscillator solutions can handle the 100~220 MHz frequency range

and meet at ease the commonly accepted phase jitter of <1 ps specification (12 KHz to 20 MHz). The recent advancement of PLL technology has

brought out families of >100 MHz crystal oscillators using simple tens of MHz of crystals with uneven phase jitter performance of 0.3~>1 ps. One

of the first successful commercial deployments of fixed frequency surface acoustic wave (SAW) oscillator (SO) was the 200~500 MHz DIP ones by

RF Monolithics, USA for the then Digital Equipment Corporation’s Alpha Microprocessor in the mid 90s. Nowadays, several suppliers can offer

small size and cost efficient SMD SAW oscillators with excellent phase jitter performance to complement the crystal oscillators mentioned above.

Selective customers prefer this solution as it is free of some of the problems from the crystal oscillator solutions- high cost of HFF and IM, spurious

modes, frequency jumping, drive level sensitivity, high cost of PLL die, etc. This paper is to provide a brief view of the current state of the

development of fixed frequency SAW oscillators. Based on the aging data of up to 20,000 hours, we will also comment on the SAW oscillator

aging performance fabricated based on different SAW wave types.

Keywords:Keywords:Keywords:Keywords: SAW; oscillator; quartz crystal; aging


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DESIGNDESIGNDESIGNDESIGNOFOFOFOFAAAA DOUBLE-CAVITIESDOUBLE-CAVITIESDOUBLE-CAVITIESDOUBLE-CAVITIES PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC PERISTALTICPERISTALTICPERISTALTICPERISTALTIC PUMPPUMPPUMPPUMPWITHWITHWITHWITH FINITEFINITEFINITEFINITE

ELEMENTELEMENTELEMENTELEMENTMETHODMETHODMETHODMETHOD

Liang XU , Ming YANG*, Wen-chu OU , Sang-di FU

College of Electronic Information and Electrical Engineering, Shanghai Jiaotong University , Shanghai,200240

*Corresponding author,E-mail:[email protected];TEL:021-34204197

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveMicro-electromechanical system has greatly developed as the drive components getting smaller and smarter. The micro-pump as one of the mainbranch of the MEMS is becoming a research focus in many countries. Micro-pumps play a key role in many fields such as micro-drug injection and thefuel supply. The piezoelectric material is an ideal material for the production of micro-peristaltic pump due to its advantages of high energy density,low power consumption, noiseless and immune to the electromagnetic interference. However, through the literature searches, two problems areprevalent in the existing piezoelectric peristaltic pump. One is the vibration of the piezoelectric oscillator has not been fully utilized, thus the flow of thepump is not high. Another is the heat generated by the pump is difficult to dissipate. In response to these two issues, we want to design a miniaturepiezoelectric peristaltic pump which can both take full advantage of the vibration of the piezoelectric ceramic to increase flow rate and lose the heatgenerated by the piezoelectric ceramic in the course of their work quickly.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn order to solve the above problems，The vibration principle of annular circular plate is analyzed in the article and the simulation of the piezoelectricactuator is made in the finite element analysis software ANSYS. A peristaltic pump which make use of the traveling wave in circular piezoelectricceramic to drive liquid is made according to the simulation results. The annular piezoelectric actuator is placed in the middle of the pump casing todivide the pump casing into upper and lower chamber. Excitation signals are imposed on different partitions of piezoelectric ceramic to excite atraveling wave in the annular piezoelectric actuator. Many cavities are formed between the valley and the pump casing, the liquid driven by thetraveling wave move from the entrance to the export. Through this design, Both the positive and negative direction vibration of annular piezoelectricelement can be fully utilized. The flow rate of the pump could be significantly improved. The heat generated by the annular piezoelectric can be takenaway by the floating liquid at the same time. Stability of piezoelectric peristaltic pump is improved. In addition, the piezoelectric peristaltic pump doesnot require the valve to ensure the unidirectional flow of liquid. The structure of the pump is simplified.

ResultsResultsResultsResultsANSYS harmonic response analysis showed that traveling wave can be excited successfully in the annular piezoelectric actuator by two-wayalternating signal. And the amplitude of traveling wave is enough to meet the design requirements of the micro-peristaltic pump

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsDue to the characteristics of simple structure, small size, low power consumption piezoelectric peristaltic pumps has a wide range of applications in thefield of automation equipment, semiconductor manufacturing, robotics. In this paper, through the analysis of annular circular plate vibration theory，wegot the conditions of generating travelingwave in annular circular plate and designed the structure of the piezoelectric peristaltic pump. Finite elementmodel of the piezoelectric actuator is established in the ANSYS. The harmonic response analysis of the piezoelectric actuator shows: The travelingwave generated in the piezoelectric stator meets the requirement of constructing piezoelectric peristaltic pump. The conception of using vibration of thepiezoelectric stator to construct piezoelectric peristaltic pump is initially realized. The article demonstrates the feasibility of using double directionvibration of piezoelectric actuator to improve flow rate of pump and dissipate heat in the angle of finite element simulation. However, whether thedual-chamber body peristaltic pump is able to significantly improve the pump output and heat dissipation needs further experimental verification.

KeywordsKeywordsKeywordsKeywords:::: FEM ; traveling-wave actuator; piezoelectric peristaltic pump; double cavities


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STUDYSTUDYSTUDYSTUDYONONONONTHETHETHETHEVIBRATIONVIBRATIONVIBRATIONVIBRATION COUPLINGCOUPLINGCOUPLINGCOUPLINGOFOFOFOFAAAAT-TYPET-TYPET-TYPET-TYPE LINEARLINEARLINEARLINEAR ULTRASONICULTRASONICULTRASONICULTRASONICMOTORMOTORMOTORMOTORUSINGUSINGUSINGUSING

LONGITUDINALLONGITUDINALLONGITUDINALLONGITUDINALTRANSDUCERSTRANSDUCERSTRANSDUCERSTRANSDUCERS

Ying-xiang LIU1*, Wei-shan CHEN1, Xiao-hui YANG1, Yu YAO2

1State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001

2School of Astronautics, Harbin Institute of Technology, Harbin 150001


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUltrasonic motors (USM) are based on the concept of driving the rotor by a mechanical vibration excited on the stator via piezoelectric effect. Theyexhibit merits such as simple structure, quick response, quiet operation, self-locking when power off, nonelectromagnetic radiation and higher positionaccuracy. In a previous study, the authors have proposed a T-type linear ultrasonic motor using longitudinal transducers, which has potentiality toobtain large output force and speed. This study focuses the research on the vibration coupling problems of the proposed motor.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsFEM method is used to investigate the vibration states of the transducers in the proposed motor. The resonance frequencies and the input impedances ofthe horizontal transducer, the vertical transducer and the motor are calculated and compared. The vibration characteristic and the input impedance of themotor are measured by a scanning laser Doppler vibrometer and an impedance analyzer, respectively.

ResultsResultsResultsResultsThe study results indicate that the vibration states of the transducers are not single longitudinal vibrations, but longitudinal and bending compositevibrations. The coupling bending vibration can cause the resonance frequencies of the motor deviate from the frequencies of the transducers and thedecreasing of the electromechanical coupling factor.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe coupling bending vibrations is a common problem for ultrasonic motors excited by longitudinal transducers, which can result in energy loss andlow output efficiency.

KeywordsKeywordsKeywordsKeywords:::: ultrasonic motor; longitudinal transducer; coupling bending vibration; input impedanceAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: This project is supported by the National Natural Science Foundation of China (No. 50875057 and No. 51105097) andthe Research Fund for the Doctoral Program of Higher Education of China (No. 20102302110007).



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THEORETICALTHEORETICALTHEORETICALTHEORETICALANDANDANDAND EXPERIMENTALEXPERIMENTALEXPERIMENTALEXPERIMENTALSTUDYSTUDYSTUDYSTUDYONONONONACOUSTICACOUSTICACOUSTICACOUSTIC SUBWAVELENGTHSUBWAVELENGTHSUBWAVELENGTHSUBWAVELENGTH IMAGINGIMAGINGIMAGINGIMAGING

BASEDBASEDBASEDBASEDONONONON ZEROZEROZEROZERO DYNAMICDYNAMICDYNAMICDYNAMICMASSMASSMASSMASS

Hai-jing SU, Xiao-ming ZHOU*, Geng-kai HU

Key Laboratory of Dynamics and Control of Flight Vehicle, Ministry of Education, and

School of Aerospace Engineering, Beijing Institute of Technology, Beijing 100081, P. R. China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAcoustic imaging is widely used in medical diagnostics and non-destructive evaluation. Acoustic images are retrieved from the scattering informationof the object. Among the scattering fields, evanescent waves that carry the fine features of the object decay rapidly in the near fields, resulting in thelimited spatial resolution. To overcome the diffraction limit, the lensing system should be able to interact with evanescent waves and enhance theiramplitudes. Acoustic metamaterials are artificial composite materials whose dispersion characteristics can be tailored to convert evanescent waves topropagating ones. This work will study the imaging mechanisms of metamaterial-based lensing system.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAcoustic metamaterials with anisotropic dynamic mass with one diagonal component being infinity and the other being zero can interact withevanescent waves. In the metamaterial, the propagating wave vector is weakly dependent on the spatial frequency of evanescent waves, meaning that allevanescent waves can be converted into traveling waves. By analytical methods, it is found that evanescent waves can be transferred based on theresonant mechanism at zero dynamic mass.

ResultsResultsResultsResultsThe metamaterial slab lens of anisotropic mass is designed. The imaging effect of the designed lens is verified by numerical simulation. In experiment,the lens is fabricated by copper membranes sandwiched by two aluminum rectangular blocks drilled by an open cylindrical hole. The experimentalsetup is constructed to measure the pressure distributions of sound waves. The results demonstrate that the designed lens can achieve the spatialresolution / 3λ .

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe subwavelength imaging can be achieved in anisotropic metamaterials with zero dynamic mass. The metamaterial lens is designed based ontheoretical and numerical analyses, and the imaging effect is verified by both numerical and experimental results.

KeywordsKeywordsKeywordsKeywords:::: metamaterial; anisotropic mass; zero mass; subwavelength imagingAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: This work was supported by the National Natural Science Foundation of China (Nos. 10832002, 11172038)


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NON-SYMMETRICNON-SYMMETRICNON-SYMMETRICNON-SYMMETRIC DYNAMICDYNAMICDYNAMICDYNAMIC CHARACTERISTICSCHARACTERISTICSCHARACTERISTICSCHARACTERISTICS OFOFOFOFSPHERICALLYSPHERICALLYSPHERICALLYSPHERICALLYSYMMETRICSYMMETRICSYMMETRICSYMMETRIC

PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC SHELLSHELLSHELLSHELL

Zu-guang YING*

Department of Mechanics, School of Aeronautics and Astronautics, Zhejiang University, Hangzhou 310027, China

* Corresponding author, E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric materials with remarkable electrical-mechanical coupling properties have been used for vibration monitoring and control. Piezoelectricshell structure has better electrical-mechanical coupling and been studied extensively. However, the description in spherical coordinates andelectrical-mechanical coupling will induce the non-symmetry in generalized stiffness. Non-symmetric systems have particular vibration characteristicsand corresponding analysis method different from conventional symmetric one. The non-symmetric dynamics of piezoelectric shells need to be studiedfurther.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThis paper studies the non-symmetric dynamic characteristics of a spherically symmetric piezoelectric shell. Firstly, basic equations of the shell aregiven in spherical coordinates. Eliminating electric potential and expanding displacement yield ordinary differential equations. The equations representa generalized multi-degree-of-freedom dynamic system with non-symmetric stiffness matrix pointed. Then, the eigenvalue and decomposition problemof non-symmetric stiffness is analyzed, and numerical results on eigenvalues and effects of piezoelectric constants are given.

ResultsResultsResultsResultsThe non-symmetric stiffness matrix is derived for a spherically symmetric piezoelectric shell. The eigenvalues of non-symmetric stiffness matrix areobtained and compared with those of symmetrized stiffness matrix. The effects of piezoelectric constants on the difference of eigenvalues ofnon-symmetric and symmetrized stiffness matrices are obtained.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe non-symmetry of piezoelectric shell has been validated. The non-symmetric eigenvalue and decomposition problem has been considered. Thenumerical results have been obtained to illustrate the effects of symmetrization and piezoelectric constants on eigenvalues. The non-symmetricdynamics of piezoelectric shells should be considered for accurate analysis and design.

KeywordsKeywordsKeywordsKeywords:::: piezoelectric spherical shell; dynamic characteristics; non-symmetry; eigenvalue problemAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: The work was supported by the National Natural Science Foundation of China (No. 11072215).


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STUDYSTUDYSTUDYSTUDYONONONONAAAANEWNEWNEWNEWLINEARLINEARLINEARLINEAR ULTRASONICULTRASONICULTRASONICULTRASONICMOTORMOTORMOTORMOTORWITHWITHWITHWITH BENDINGBENDINGBENDINGBENDING PZTPZTPZTPZT ELEMENTSELEMENTSELEMENTSELEMENTS

Xiao-hui YANG*, Wei-shan CHEN, Ying-xiang LIU, Jun-kao LIU

State Key Laboratory of Robotics and System, Harbin Institute of Technology, Harbin 150001

*Corresponding author, E-mail: [email protected]; Tel.: 0451-86417891

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUltrasonic motor (USM) is a new type actuator via converse piezoelectric effect of the PZT elements developed from the 1980s. Ultrasonic motors havereceived profound attention by their merits of high torque at low speed, compact size, high holding torque with no power consumption, simple structure,high positioning accuracy, no electromagnetic radiation, and so on. In this study, the authors proposed a new linear ultrasonic motor with bending PZTelements. The vibration and impedance characteristics of the new motor are discussed.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe vibration characteristics and the resonance frequencies of the ultrasonic motor modal are obtained by using ANSYS software. The vibration andimpedance characteristics of the prototype motor are measured by a scanning laser Doppler vibrometer and an impedance analyzer, respectively.

ResultsResultsResultsResultsOnly employing bending PZT can generate both longitudinal and bending vibrations. When the phase difference temporally of two exciting voltages is60 deg, the end tips of the horns are more appropriate for driving the runner whose vibration amplitudes are largest in the new motor.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThis study verifies a new exciting method of ultrasonic motor using longitudinal and bending vibration modes; and the proposed exciting mode ofbending PZT elements in the new motor can be utilized at many other longitudinal and bending hybrid ultrasonic motors.

KeywordsKeywordsKeywordsKeywords:::: ultrasonic motor; bending PZT elements; vibration characteristics; impedanceAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: This project is supported by the National Natural Science Foundation of China (No. 50875057 and No. 51105097) andthe Research Fund for the Doctoral Program of Higher Education of China (No. 20102302110007).



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AAAANOVELNOVELNOVELNOVELROTARYROTARYROTARYROTARYPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICMOTORMOTORMOTORMOTOR FORFORFORFORAEROSPACEAEROSPACEAEROSPACEAEROSPACEAPPLICATIONAPPLICATIONAPPLICATIONAPPLICATION

Xiao-long LU, Jun-hui HU*, Chun-sheng ZHAO

State Key Laboratory of Mechanics and Control of Mechanical Structures,

Nanjing University of Aeronautics and Astronautics,

29 Yudao Street, Nanjing 210016, People’s Republic of China.


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric motors have the merits of high ratio of torque to volume, high positioning precision, intrinsic holding torque, etc., compared to theconventional electromagnetic motors. There have been several potential applications for this type of motor in aerospace exploration, but bearings andbonding mechanism of the piezoelectric ring in the motors limit the performance of them in the space operation conditions. It is known that theLangevin type transducer has excellent energy efficiency and reliability. Hence using the Langevin type transducer in ultrasonic motors may improvethe reliability of piezoelectric motors for space applications.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA novel in-plane mode rotary piezoelectric motor is designed in this work. Four Langevin type bending vibrators are placed separately around the ringshaped stator and used to excite an in-plane mode travelling wave vibration of the ring stator. Teeth are cut out on the inner surface of the stator ring forenlarging the vibration amplitude. Two tapered rotors are assembled to the inner ring of the stator and clamped together by screw nut.

ResultsResultsResultsResultsBy using the Doppler laser vibrometer system, the measured stator’s vibrating frequency is near 45 kHz and the vibrating amplitude is 1.5 µm at200Vp-p input voltage and resonance. The metal-metal pair is chosen as the contact pair, and the measured no-load speed is 120 r/min and the stallingtorque is near 0.3 N•m.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThere is no bearing in the designed piezoelectric motor, and its vibration excitation is achieved by four Langevin transducers. Thus there are nolubricating oil and bonding layer in the motor. These measures make the piezoelectric motor much more reliable than the conventional one, and fit forspace applications.

KeywordsKeywordsKeywordsKeywords:::: piezoelectric motor; bending mode Langevin transducer; space applicationAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements:::: The work was supported by Innovation and Entrepreneurship Program of Jiangsu, China, NUAA (No. 56XZA12044 andS0986-013 (1001-909386)), National Science Foundation of China (No: 51075212), and the Priority Academic Program Development of JiangsuHigher Education Institutions.



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TOPOLOGYTOPOLOGYTOPOLOGYTOPOLOGYOPTIMIZATIONOPTIMIZATIONOPTIMIZATIONOPTIMIZATIONOFOFOFOFTWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALPHONONICPHONONICPHONONICPHONONIC CRYSTALSCRYSTALSCRYSTALSCRYSTALS USINGUSINGUSINGUSING FEMFEMFEMFEM

ANDANDANDANDGENETICGENETICGENETICGENETICALGORITHMALGORITHMALGORITHMALGORITHM

Hao-wen DONG 1*, Xiao-xing SU 2, Yue-sheng WANG 1

1 Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 1001012 School of Electronic and Information Engineering, Beijing Jiaotong University, Beijing 100101

* Corresponding author, E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveBecause of the potential application of the phononic crystals (PCs) (noise reduction, acoustic filtering and waveguiding,etc) and with the in-depthdevelopment of this field, the topological optimization and inverse design of PC structures have provoked certain degree of interests within thecommunity in recent years. In the present work, we carry out the band gap optimization of the two-dimensional (2D) solid binary-component PCs. Thefinite element method (FEM) and the genetic algorithm (GA) are used as the forward calculation method and optimization scheme, respectively.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe forward FEM calculation of the band structures is accomplished by the standard software Abaqus. In the calculation, the parameter modeling isrealized by modifying the input file and running the scriptlet and we choose iterative method Lanzcos to calculate the eigenfrequencies correspondingto each of the selected Bloch wave vector. Finally, with the scriptlet of Abaqus,the considered 2D PC is extracted from the obtained band structure. Inthe GA optimization sheme, we encode the materials distribution by dividing the unit cell into N × N elements; then the genetic operators(selection,crossover andmutation are applied to create children replacing their parent in the next generation. One generation after another is created insuch a manner until a convergence criterion is met. An elitist selection scheme is applied in the GA. If the best one of the new generation is not moreexcellent than that of the parent generation, the latter one will replace a chromosome of the new generation randomly. At last, the materials distributionparameters of chromosome are transferred to Abaqus by using the Python language which can call the Abaqus kernel to make pretreatment andpost-processing.

ResultsResultsResultsResultsSome preliminary numerical results are presented. The component materials are Pb and Epoxy. In the initial population, the seed chromosomecorresponds to a PC stucture with the maximum relative width is used. In the optimization process, GA begins to converge with about 400 generations;and the relative width of the first band gap of the obtained optstructures are significantly improved by 200.6% and 271.8% if compared with that of theseed structure. The optimized topologies for in-plane waves are seen to be a square inclusion of Pb with sligthly rounded corners. For the out-planewaves, the optimized topologies approaches a circular inclusion. For comparison, the perfect square inclusions and the perfect circular inclusions withdifferent filling fractions are studied. It is interesting to find that the relative band gap sizes of optimal structures are bigger than regular square andcicular inclusions.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results show that the FEM combined with the GA can be effectively used to perform the topological optimization of the 2D PC. Future studies willconcentrate on improved objective functions and the full 3D case.

Keywords:Keywords:Keywords:Keywords: phononic crystals; topology optimization; finite element method; genetic algorithmAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 51178037 and 61007007).



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SPOTSPOTSPOTSPOT FORMATIONFORMATIONFORMATIONFORMATIONANDANDANDAND RADIALRADIALRADIALRADIALALIGNMENTALIGNMENTALIGNMENTALIGNMENTOFOFOFOFSILVERSILVERSILVERSILVER NANOWIRESNANOWIRESNANOWIRESNANOWIRES ININININAAAA DROPLETDROPLETDROPLETDROPLETONONONON

LOW-FREQUENCYLOW-FREQUENCYLOW-FREQUENCYLOW-FREQUENCYULTRASONICULTRASONICULTRASONICULTRASONIC STAGESTAGESTAGESTAGE

Yu-jie ZHOU, Jun-hui HU*, Hua-qing LI, Ning LIState Key Lab of Mechanics and Control of Mechanical Structures

Nanjing University of Aeronautics and Astronautics, Nanjing 210016*Corresponding author, E-mail: [email protected]; Tel.: 025-84891681

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePatterning and alignment of one-dimensional nanostructures are very important in nanofabrication. The patterning is an indispensible process in thefabrication of nanoelectronic components such as field–effect transistors, crossed junctions and rotational actuators. And the alignment is an importantprocess in the fabrication of nano composite materials which are widely used in various novel electronic and photonic devices. In this work, we havepurposed the spot formation and radial alignment of silver nanowires (AgNWs) by controlled low-frequency ultrasound.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe manipulations of AgNWs are based on a low-frequency ultrasonic stage and a AgNW suspension droplet at the center of the ultrasonic stage. Theultrasonic stage with 50.8 mm diameter and 3.5 mm total thickness, operates at a flexural vibration mode symmetric about the center of itself and has avibration peak at the center. The AgNW suspension is formed by deionized water and dissociated AgNWs in it. The operating frequency of theultrasonic stage is 21.3 kHz and the AgNWs have diameter of 100 nm and length of 30 μm approximately.ResultsResultsResultsResultsWhen the ultrasonic stage vibrates properly, AgNWs on the substrate surface in the droplet may move to the stage center and form a spot or rotate tothe radial direction and align in the direction pointing to the stage center. The diameter and thickness of formed spot are several hundred microns andseveral microns, respectively, when the vibration velocity of the stage center is around 100 mm/s (0-p). The rotation velocity of a single AgNW can beup to 31°/min when the vibration velocity of the stage center is 30 mm/s (0-p) for a droplet of 40 μL. After the droplet dries out by natural evaporationwithout ultrasound, the spot and radial alignment have little change in the size and pattern.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsWe have demonstrated that nanowires in a micro liter droplet located at the center of a low-frequency ultrasonic stage can transfer to the stage center toform a spot or rotate to the radial direction, when the stage vibration is proper. The ultrasonic stage vibrates symmetrically about its center, with avibration peak at the center. As the ultrasonic stage vibration increases, the spot diameter deceases and spot thickness increases. Principle analysesshow that the spot formation and radial alignment of AgNWs are caused by the acoustic streaming in the radial direction (the direction pointing to thestage center) in the droplet.

Keywords:Keywords:Keywords:Keywords: spot formation; radial alignment; silver nanowires; acoustic streaming; ultrasonic stageAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work is supported by the following funding organizations in China: National Science Foundation of China(No.91123020 & No.51075212), NUAA (No. S0896-013 or No. 909386 & No. 56XZA12044), the Innovation and Entrepreneurship Program ofJiangsu and PAPD.



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PICK-AND-PLACEPICK-AND-PLACEPICK-AND-PLACEPICK-AND-PLACEOFOFOFOFAAAA SINGLESINGLESINGLESINGLE NANOWIRENANOWIRENANOWIRENANOWIRE USINGUSINGUSINGUSINGACOUSTICACOUSTICACOUSTICACOUSTIC STREAMINGSTREAMINGSTREAMINGSTREAMING

Hua-qing LI, Jun-hui HU*, Yu-jie ZHOU, Ning LIState Key Lab of Mechanics and Control of Mechanical Structures

Nanjing University of Aeronautics and Astronautics, Nanjing 210016*Corresponding author, E-mail: [email protected]; Tel.: 025-84891681

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe pick-and-place of a single nanocomponent such as nanoparticle, nanowire and nanotube is an important technology in the assembly of nanostructures, fabrication of high-performance electronic and photonic devices, etc. Optical tweezers, atomic force microscope (AFM) based manipulators,scanning electron microscope (SEM) based manipulators, and electrostatically and electrothermally actuated grippers, have been proposed to pick andplace a single nanoscale component. However, there are some limitations in these existing techniques. The laser beam may be harmful to somebiological samples; the AFM based manipulators have bulky systems; the SEM based manipulators require ultra-high vacuum and low temperatures;the electrostatically and electrothermally actuated grippers generate electric field and spatial temperature gradient. To circumvent these limitations, newstrategies for the pick-and-place of nanoscale entities are desired.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe have proposed a new strategy to pick and place a single nanowire in suspension on the surface of glass substrate, using the acoustic streaminggenerated by the bent tip of an acoustic needle. Single nanowires can be sucked to the acoustic needle tip, trapped under the tip without contact with thetip, transferred with the acoustic needle, and released when the acoustic needle vibration is switched off. The technique has the merits such as simpleand compact structure, very low cost, and harmless to the manipulated samples, etc.ResultsResultsResultsResultsFirst, we researched the maximum distance that the Ag nanowires with different length aligned with flow direction of acoustic streaming could besucked for different vibration amplitudes at a fixed reference point. The maximum distance increases with the vibration amplitude increase for Agnanowires with different length. The transport of a single Ag nanowire was investigated. As the Ag nanowire approaches the needle tip, the transportvelocity increases first and then decreases when the amplitude is small, and increases all the way when the amplitude is large. In addition, the Agnanowire can rotate to align with the direction of acoustic streaming.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn this work, we have put forward a novel strategy that can carry out the pick-and-place manipulation of a single nanowire in water film on the surfaceof a glass substrate by the bent tip of an ultrasonic needle, with essentially no restrictions on the material properties of the nanowire. Attracting andtrapping forces on the single nanowire, toward the ultrasonic needle tip, are generated by the acoustic streaming induced by the ultrasonic needle. Wedemonstrate that a single nanowire in water film on the glass substrate surface is sucked to the ultrasonic needle tip, trapped under the tip withoutcontact with the tip, transferred with the ultrasonic needle and released when the vibration is switched off.

Keywords:Keywords:Keywords:Keywords: pick-and-place; nanowire; acoustic streaming; ultrasonic needleAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work is supported by the following funding organizations in China: National Science Foundation of China(No.91123020 & No.51075212), NUAA (No. S0896-013 or No. 909386 & No. 56XZA12044), the Innovation and Entrepreneurship Program ofJiangsu, and PAPD.



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RESEARCHRESEARCHRESEARCHRESEARCHONONONON LOCKINGLOCKINGLOCKINGLOCKINGDEVICEDEVICEDEVICEDEVICE DRIVENDRIVENDRIVENDRIVEN BYBYBYBYULTRASONICULTRASONICULTRASONICULTRASONICMOTORMOTORMOTORMOTOR FORFORFORFORMAGNETICMAGNETICMAGNETICMAGNETIC

BEARINGBEARINGBEARINGBEARING FLYWHEELFLYWHEELFLYWHEELFLYWHEEL

Xiao-niu LI, Sheng-qiang ZHOU*, Zhi-yuan YAOState Key Laboratory of Mechanics and Control of Mechanical Structures，

Nanjing University of Aeronautics and Astronautics, Nanjing 210016, CHINA* Corresponding author, E-mail: [email protected]; Tel.: 025-84896346

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe magnetic bearing flywheel is a new type of inertial actuator used in satellite attitude control. A locking device is used to eliminate the gap betweenthe rotor and the stator of magnetic bearing flywheel in order to prevent it from shock and vibration. The present pyrotechnical or magnetic motoractuated locking devices have the disadvantages such as high, shock, large size, and heavy weight. Taking the advantage of ultrasonic motors such ashigh torque, small size, light weight, self-locking, and rapid response, a kind of locking device driven by ultrasonic motors for magnetic bearingflywheel, is introduced in this paper.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe system of locking device includes mechanical structure and motion control. The driving source of mechanical structure applies a traveling rotarywave ultrasonic motor (TRUM). The transmission employs worm gear so as to drive the executive body, protecting the flywheel. The core of themotion control system consists of the microcontroller and the ultrasonic motor driving circuit. The microcontroller is used to receive commands andmonitoring signals of the mechanism. After signals are processed by the microcontroller, it send level signal to driver circuit for ultrasonic motor. Thedriver circuit generates high frequency two-phase sinusoidal voltages with 90°phase difference. Then the locking device implements stroke control.Because ultrasonic motor is a new type of micro motor, its conditions operating characteristics must be tested. Then several experiments are done, forexample, testing the power input and temperature characteristics of the ultrasonic motor that is working on the locking device for magnetic bearingflywheel. In order to evaluate the locking device driven by ultrasonic motors for magnetic bearing flywheel, test the strain of actuated clutch (theexecutive body of the locking device). Due to the locking device driven by ultrasonic motors works fit for space applications, environment andvibration tests are carried out.ResultsResultsResultsResultsTest results show that the device can complete the lock or unlock action within 260s. The power input of the ultrasonic motor is stable. The wholesystem is driven by 12 V DC, as the device locking, the input current of the system is 0.56A; as unlocking input current of the system is 0.56A. Thetemperature rise of ultrasonic motor is 25. The force of actuated clutch is 17.1 N along with the radial. It also undergoes the environment andvibration test which simulates the launch phase.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIt is concluded that the new locking device driven by ultrasonic motors owning advantages of small size, light weight, low shock, and easy to reset hasa potential usage in space engineering.

Keywords:Keywords:Keywords:Keywords: ultrasonic motor; magnetic bearing flywheel; locking device; microcontrollerAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 50975136).


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PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC FRAMEFRAMEFRAMEFRAMEWITHWITHWITHWITHNON-UNIFORMNON-UNIFORMNON-UNIFORMNON-UNIFORMTHICKNESSTHICKNESSTHICKNESSTHICKNESS FORFORFORFORVIBRATIONVIBRATIONVIBRATIONVIBRATION ENERGYENERGYENERGYENERGY

HARVESTINGHARVESTINGHARVESTINGHARVESTING

Song-mao CHEN, Jin-juan ZHOU, Jing SUN, Jun-hui HU *

State Key Lab of Mechanics and Control of Mechanical Structures

Nanjing University of Aeronautics and Astronautics, Nanjing 210016* Corresponding author, E-mail: [email protected] Tel.: (+86) 25-84891681

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveWith the evolution of low power electronics, harvesting the structural vibration energy, which is clean, ubiquitous and renewable, has gainedincreasingly extensive attentions from worldwide researchers in the recent decade for its great potentials for applications in areas of wireless sensornetworks (WSNs), autonomous low power microsystems, distributed computing and portable alternative power sources, remote sensing and actuation,etc., to replace or replenish the traditional power supply such as battery. A number of vibration energy harvesters (VEH) using the piezoelectric effectand electromagnetic induction have been proposed and developed, with various power conditioning and energy storage solutions. Generally, a typicalpiezoelectric VEH employs a uniform cantilever beam structure (piezoelectric unimorph or piezoelectric bimorph) with a proof mass at its tip andexcitation at its base. This type of structure works in resonance and the output power decreases significantly when the working frequency shifted awayfrom the resonance frequency, and hence has narrow working bandwidth, which limits its application range. At the same time, most of the cantileverbeams are uniform or variable in width, and the structure with variable thickness has been rarely investigated. In this paper, the authors have proposed athickness non-uniform piezoelectric frame structure using vibro-impact for broadband vibration energy harvesting. As shown in Fig. 1, the frame hasthree evenly spaced rectangular grooves with identical size, and three identical rectangular piezoelectric plates bonded on the frame. Each piezoelectricplate has the same central position as corresponding groove, and the three piezoelectric plates are connected in parallel electrically. The whole structurecan be bolted to an electric shaker or vibrating body to generate power.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA vibro-impacting piezoelectric frame structure, as shown in Fig. 1, has been proposed, designed and fabricated. Numerical study using finite elementcode ANSYS/Multiphysics is conducted and the numerical results are verified by experiments. As shown in Fig. 2, SOLID5, SOLID45 and CIRCU94are used to model the piezoelectric plate, steel frame and electric resistor, respectively.ResultsResultsResultsResultsIt has been shown by harmonic analysis that when the applied tip displacement is 0.5 mm (0-p), and the frame operates at the 1st flexural resonancemode (250.3 Hz), the maximum total output power of the harvester with uniform thickness is 0.77 mW at the optimal load resistance of 170 kΩ; whenthe applied tip displacement is 0.5 mm (0-p), and the frame operates at the 1st flexural resonance mode (225.9 Hz), the maximum total output power ofthe proposed non-uniform harvester is 1.33 mW at the optimal load resistance of 190 kΩ. Hence, a 73% increase in total power output has beenobtained. The actual power enhancement of the proposed harvester is currently under experimental investigation.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsCompared to traditional uniform piezoelectric cantilever beam, the proposed harvester structure can both significantly increase the total output power.

Keywords:Keywords:Keywords:Keywords: vibration energy harvesting; piezoelectric; vibro-impacting; thickness; non-uniform thicknessAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the Funding of Jiangsu Innovation Program for Graduate Education (No.CXLX12_0140, theFundamental Research Funds for the Central Universities), NUAA Funds (No. S0896-013 and No. 56XZA12044), the Innovation and EntrepreneurshipProgram of Jiangsu, and PAPD.

Fig. 1 Schematic of the piezoelectric frame structure Fig. 2Finite element model of the piezoelectric vibration energy harvester



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EXPERIMENTALEXPERIMENTALEXPERIMENTALEXPERIMENTAL INVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATIONOFOFOFOFCHARACTERISTICSCHARACTERISTICSCHARACTERISTICSCHARACTERISTICS OFOFOFOFTHETHETHETHECHLADNICHLADNICHLADNICHLADNI EFFECTEFFECTEFFECTEFFECTWITHWITHWITHWITH

HELICALHELICALHELICALHELICALMOTIONMOTIONMOTIONMOTION

Xiao-bo ZHU, Jun-hui HU*

State Key Laboratory of Mechanics and Control of Mechanical Structures

Nanjing University of Aeronautics & Astronautics, Nanjing 210016, China*Corresponding author, E-mail: [email protected]; Tel.: 025-84891681

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveChladni effect was firstly reported in 1787 by the German physicist Chladni. It refers to the phenomenon that sand particles on a flexurally vibratingplate move to and agglomerate at the nodal positions of the plate. Although Chladni effect has applications in the vibration mode visualization,ultrasonic motor, and micro and nano manipulations, researches on its characteristics are scarce.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, Chladni effect based on a metal plate vibrating flexurally is invested in air. The metal plate, made of aluminum, is 4.5 mm wide and 30mm long. It is tapered along the length direction of itself, and the thickness of the tapered plate is 3 mm at its root and decreases to zero linearly asapproaching the sharp end. The tapered plate is mechanically driven by a sandwich shaped ultrasonic actuator. There are several nodal points along thex axis on the surface of the metal trapped plate. Shrimp eggs with 440 μm diameter approximately are used as the particles for measurement. The locusof a particle cluster or single particle moving to the nodal point is helical. When the operating frequency was around 89.20 kHz (in resonance), thesmall particles on the metal plate surface would move to the nodal points on the metal plate in the forms of one-particle two-particle and three-particleclusters. The characteristics of average radial velocity of particle clusters around a nodal point (x=10 mm, y=0 mm) on a metal plate are experimentallyinvestigated in detail.ResultsResultsResultsResultsThe average radial velocity of a single particle decreases as the vibration increases, and the average radial velocity is affected by the particle number ina cluster. As the distance between initial radial position of a single particle and nodal point N increases, the average radial velocity of the particlemoving to nodal point N increases first and then decreases; the average radial velocity of the particle cluster or single particle decreases as the metalplate vibration increases.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe experimental results indicate that the radial speed of particle(s) in the Chladni effect with helical motion is not uniform along the radial direction,and a large vibration does not necessarily cause a large radial speed of particle(s) because of the centrifugal force on the particle(s). The results in thiswork may be used in the further investigation of Chladni effect.

Keywords:Keywords:Keywords:Keywords: Chladni effect; nodal point; particle; average radial velocityAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work is supported by the following funding organizations in China: National Science Foundation of China(No.51075212 & No.91123020), NUAA (No.56XZA12044 & No. S0896-013 or No.1001-909386), the Innovation and Entrepreneurship Project ofJiangsu, and PAPD.



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3-D3-D3-D3-DMANIPULATIONSMANIPULATIONSMANIPULATIONSMANIPULATIONSOFOFOFOFAAAA SINGLESINGLESINGLESINGLE NANOWIRENANOWIRENANOWIRENANOWIRE USINGUSINGUSINGUSING UNIFORMUNIFORMUNIFORMUNIFORMMICROMICROMICROMICRO FIBERGLASSFIBERGLASSFIBERGLASSFIBERGLASS ININININ

ULTRASONICULTRASONICULTRASONICULTRASONICVIBRAIONVIBRAIONVIBRAIONVIBRAION

Ning LI, Jun-hui HU, Hua-qing LI, Yu-jie ZHOUState Key Lab of Mechanics and Control of Mechanical Structures,

Nanjing University of Aeronautics and Astronautics, Nanjing 210016* Corresponding author, E-mail: [email protected]; Tel.: 025-84891681

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveNanostructures are promising in building the novel microelectronic and photonic devices, and micro/nano actuators. The existing methods ofmanipulating an individual nanowire include optical tweezers, atomic force microscope (AFM) and scanning electron microscope (SEM) basedmanipulators, magnetic actuators, and electrostatically and electrothermally actuated grippers. Limitations of these methods include the heat induceddamage of manipulated biological samples, bulky and expensive manipulators, selectivity to the manipulated samples, etc. Acoustic method is supposedto be incapable of manipulating individual nanowires because of relatively long wavelength and the disturbance of acoustic streaming. In this report, weprovide an acoustic method for manipulating individual nanowires. The merits of acoustic manipulation methods include harmlessness to biologicalsamples, simple actuator structure, convenient use, low cost, high manipulation efficiency and no selectivity to the manipulated samples.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe ultrasonic actuator in our experiments consists of a micro fiberglass, acoustic needle and transducer, and the fiberglass is mechanically excited bythe acoustic needle excited by the ultrasonic transducer. Single silver nanowires (AgNWs) with diameter of 100 nm and length of several to 30 μm inwater suspension on the surface of a silicon substrate can be sucked and trapped by the micro fiberglass in ultrasonic vibration, moved with the wholeactuator in 3-D, and then released when the vibration is switched off. The operating frequency is around 135 kHz.ResultsResultsResultsResultsWe took the video of the 3-D manipulations to show the sucking, trapping, transfer and release of a single AgNW with length of 20 μm and diameter of100 nm. In the experiment, the manipulation is quite stable. We also measured the effect of the actuator vibration displacement on the maximum lengthof an individual AgNW which can be sucked onto the fiberglass tip. In the experiment, the individual AgNW is just under the fiberglass tip. As thevibration increases, the maximum length increases first and then decreases. Based on the experimental phenomena, we analyzed the principle of themanipulations. It shows that the acoustic streaming and acoustic radiation force are responsible of the sucking and trapping.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsWe show that the acoustic fiberglass with a diameter of 10 µm can suck and trap a single AgNW under its tip in water by the acoustic streaming andacoustic radiation pressure, and can also move the trapped AgNW in 3-D pattern and release it. Experiments show that the manipulation is quite stable.This method may be used to pick and place magnetic, nonmagnetic, biological and non-biological nano samples. The actuation system in this method isvery simple, and easy to operate.

Keywords:Keywords:Keywords:Keywords: acoustic fiberglass; nanowire; acoustic streaming; acoustic radiation force; manipulation.Acknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work is supported by the following funding organizations in China: National Science Foundation of China(No.91123020 & No.51075212), NUAA (No. S0896-013 or No. 909386 & No. 56XZA12044), the Innovation and Entrepreneurship Program ofJiangsu, and PAPD.



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ANANANAN EXPERIMENTALEXPERIMENTALEXPERIMENTALEXPERIMENTALSTUDYSTUDYSTUDYSTUDYONONONONTHETHETHETHE STRUCTURESTRUCTURESTRUCTURESTRUCTURE OFOFOFOFTHETHETHETHE INTERNALINTERNALINTERNALINTERNALIMPACTIMPACTIMPACTIMPACTTYPETYPETYPETYPEVIBRATIONVIBRATIONVIBRATIONVIBRATION ENERGYENERGYENERGYENERGYHARVESTERHARVESTERHARVESTERHARVESTER

Jing SUN, Jun-hui HU*, Jin-juan ZHOU, Song-mao CHENState Key Laboratory of Mechanics and Control of Mechanical Structures

Nanjing University of Aeronautics & Astronautics, Nanjing 210016, China*Corresponding author, E-mail: [email protected]; Tel.: 025-84891681

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveTo increase the vibration energy-harvesting capability of the piezoelectric generator based on a cantilever beam, the authors’ research group hadproposed the internal impact type vibration energy harvester (IITVEH) that not only uses the strain change of piezoelectric components bonded on acantilever beam, but also employs the proof mass at the tip of the cantilever beam to hit piezoelectric components located on the 2 sides of the proofmass. In this work, we study the effect of the structure topology of IITVEH on its output power.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsTwo structural designs of IITVEH utilizing both electromagnetic and piezoelectric elements are introduced, which are named as U & Y type structures,respectively. For U type structure, it is comprised of two parts, that is, the top and bottom frames, and the cantilever beam between them. The top andbottom frames have the same shape and size, and each consists of a horizontal root, vertical connection and horizontal beam. The root, connection andbeam in each frame are made of rectangular aluminum plate. A screw structure fastens the horizontal roots of the top and bottom frames to construct aholder for the U type IITVEH and clamps a phosphor bronze beam between the top and bottom frames. Two permanent magnets are bonded to the twosides of the cantilever beam tip. Coils are bonded to the outer surfaces of the tip of the top and bottom frames. The piezoelectric components are locatedon the surfaces of the vertical connections and the horizontal beams. The Y type structure is formed by tilting the vertical connections in the U typestructure, and its total length, height and width are identical to the U type structure. In the Y type structure, all of the piezoelectric components arebonded on the tilted connections, and the same electromagnetic units as the U type structure are used. The output electric power of the U and Y typestructures is compared for the same vibration excitation conditions.ResultsResultsResultsResultsExperimental results show that when the vibration excitation displacement is 0.5 mm (rms), the total maximum output power is 10.172 μW for the Utype structure at excitation frequency of 39 Hz, and 21.151 μW for the Y type structure at excitation frequency of 41 Hz. It shows that the output powerPmax for the Y type structure is 207.9% of that for the U type structure.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe output power from the electromagnetic units of them, operating at the same excitation conditions, was measured and compared. It is found that theoutput power from the electromagnetic units is very close. Thus the total output power difference is caused by the piezoelectric units. The tiltedconnection in the Y type structure may have a larger strain when subjected to an identical same hit of the proof mass. As a conclusion, the Y typestructure has a larger total output power than the U type structure.

Keywords:Keywords:Keywords:Keywords: energy harvester; vibration; internal impact typeAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was supported by the Innovation and Entrepreneurship Program of Jiangsu, China, NUAA (Funding No.56XZA12044 and S0986-013 or 1001-909386), PAPD, and the Funding of Jiangsu Innovation Program for Graduate Education (No.CXLX12_0140,the Fundamental Research Funds for the Central Universities).



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USINGUSINGUSINGUSING PMMAPMMAPMMAPMMARADIATIONRADIATIONRADIATIONRADIATIONHEADHEADHEADHEADTOTOTOTO IMPROVEIMPROVEIMPROVEIMPROVETHETHETHETHETRANSMITTINGTRANSMITTINGTRANSMITTINGTRANSMITTING PERFORMANCEPERFORMANCEPERFORMANCEPERFORMANCEOFOFOFOF

THETHETHETHETRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCER BYBYBYBYFINITEFINITEFINITEFINITE ELEMENTELEMENTELEMENTELEMENTMETHODMETHODMETHODMETHOD

Hui-sheng LIU1,2 , Xi-ping MO1*

1 Institute of Acoustics, Chinese Academy of Sciences, Beijing 1001902 Graduate School of the Chinese Academy of Sciences, Beijing 100029


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUnderwater acoustic communication is often need wideband transducer to improve the communication quality, a transducer with a flat transmittingvoltage level in a broad working frequency band is the best choice, but it is difficult to get a transducer with this characteristic. Some methods are takento improve the transducer performance, such as the matching layer technique is one of these used popularly. There is a question that finds anappropriate matching layer material is not easy because of no suitable material in nature, most of which is got by artificial synthesis and with anacoustic uniformity is also a painful task. The PMMA material has a similar acoustic impedance to the water and easy to obtain, and using the materialas the radiation head of the Tonpilz transducer for performance improvement is less explored in literature, the effect of a PMMA structure to thetransducer performance is discussed .StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA finite element method is used in this paper, the relationships between the head geometry size and its mode is analyzed for in-air, the transmittingvoltage response effected by the head geometry size in water is also studied.ResultsResultsResultsResultsThe transducer has two modes in working frequency band, in a word, the thicker the PMMA head, the lower the two modal frequencies in air, besidesthe frequencies with a small fluctuation in different thickness, which is agreed with the theory of half-wavelength resonator. After size optimization ,the transmitting voltage response is only a 1.1dB variation from 27kHz to 51kHz.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe finite element results show that it is feasible to the use the new PMMA head structure to improve the flatness of the transmitting voltage responseof the Tonpilz transducer.

Keywords:Keywords:Keywords:Keywords: broadband; tonpilz transducer; transmitting voltage response; matching layer; PMMA


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THEORETICALTHEORETICALTHEORETICALTHEORETICALANDANDANDAND EXPERIMENTALEXPERIMENTALEXPERIMENTALEXPERIMENTALSTUDYSTUDYSTUDYSTUDYONONONONAAAANEWNEWNEWNEWSTRUCTURESTRUCTURESTRUCTURESTRUCTURE FREE-FLOODEDFREE-FLOODEDFREE-FLOODEDFREE-FLOODEDRINGRINGRINGRINGTRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCER

Xin-ran XU 1,2*

1 Hangzhou Applied Acoustics Research Institute, Hangzhou 3100122 Science and Technology on Sonar Laboratory, Hangzhou 310012


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe SONAR transducers can be used for underwater target detection, acoustic communication and many other underwater applications. Since at leasttwenty years ago, the need of broadband, high efficiency, great depth transducers has never stopped, and consequently this topic has been attractingmore and more researchers’ interests. Ring transducer is one of the most common types of underwater transducer, which has been widely used as anacoustic source. It may be operated either in piezoelectric 31-mode or in 33-mode with air-backed or free flooded inner cavity. On the one hand, thepiezoelectric 33-mode ring transducer with piezoelectric ceramic bars and electrode bars stuck alternately can achieve higher coupling coefficient andhigher output power than its 31-mode counterpart. On the other hand, the free-flooded design that couples the Helmholtz cavity resonance and the ringresonance can obtain quite wide bandwidth and depth independence performance. However, for a given frequency, the dimension of the ring transduceris proportional to the effective sound speed of the ring, which makes it not compact for practical application. The purpose of this work is to increase thering transducer’s compactness and maintain its high output power over a rather wide bandwidth.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, to minimize the transducer’s dimension and maintain its performance, a perforated electrode design in free-flooded 33-mode ringtransducer is proposed. The perforated electrode bars can decrease the effective stiffness of the composite ring and thus lower its effective sound speed.As a result, the transducer of same resonant frequency could be smaller. Finite element method is applied to simulate the performance of the transducer,and several design parameters are optimized to achieve higher output power over a wider bandwidth. Two sample transducers of the same dimensionare manufactured, in which one with perforated electrodes and the other without. The electrical and acoustical performance parameters of the twotransducers are tested, including the admittance curve in air and in water, the transmitting voltage response and the directivity pattern. The influence ofdifferent shape openings of transducer on its performance is also studied experimentally.ResultsResultsResultsResultsBy FEM modeling, we find that several parameters can affect the ring transducer’s performance, such as the radius of the ring, the thickness of theceramic, the height of the ring and the number of the ceramic bars. The measured performances of the transducer agree well with that predicted by FEMsimulation. The designed transducer’s -6dB bandwidth ranges from 6 kHz to 10 kHz. The transducer with perforated electrode has lower resonancefrequency than its counterpart.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe perforated electrode bars introduced in this paper can refine the free-flooded transducer’s performance, which results in lower resonance frequencyand wider bandwidth. The design method developed in this paper can be used to improve other underwater transducer performance effectively andinexpensively. The shape of the opening of the ring transducer has an effect on its performance, and its mechanism should be studied carefully in thefuture.

Keywords:Keywords:Keywords:Keywords: free-flooded ring transducer; perforated electrode bars; FEM



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AAAAU-SHAPEU-SHAPEU-SHAPEU-SHAPETRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCERARRAYARRAYARRAYARRAYOFOFOFOFSHALLOWSHALLOWSHALLOWSHALLOWWATERWATERWATERWATER MULTIMULTIMULTIMULTI BEAMBEAMBEAMBEAM SONARSONARSONARSONAR SYSTEMSYSTEMSYSTEMSYSTEM

Zhen-yu ZHENG 1,2*

1 Hangzhou Applied Acoustics Research Institute, Hangzhou 3100122 Science and Technology on Sonar Laboratory, Hangzhou 310012


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSince the first multi beam sonar was developed by General Instrument Inc in 1964, its scientific, commercial and military value has been widelyaccepted. In recent years, several kinds of multi beam sonar systems are manufactured in various countries. These systems have comprehensiveapplications such as real time sea-floor classification, hydrographic survey and object detection. Researches on multi beam sonar system have beenengaged in China since 1980. Its underwater transducer array has similar mechanisms to those developed by other countries, but there is still some gapin the fabrication technique compared with advanced level in the world. When multi beam sonar is applied for bottom detection, the intensity of theecho from the vertical direction is much greater than that from the oblique direction. This situation can be compensated by changing the gain of thereceiving transducers. However, designing a transducer array with side beam intenser than the central beam can avoid changing gain and increase thesurvey performance. In this paper, a U-shape array deployment is proposed, which can control the space distribution of energy emitted from thetransducer.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, piezoelectric ceramic pillars and matching layer material are combined to form a U-shape transducer array. Wide bandwidth of this kindof transducer insures it can operate in double frequency form. The equivalent circuit model and finite element model are utilized to analyze theelectrical and acoustic performance of the U-shape transducer. The admittance curve and the radiation pattern are calculated in ANSYS, and the desiredbeam pattern is acquired. Under the guidance of theoretical analysis, the multi beam sonar array is developed. Injection molding on the U-shape steelcore is used as the base of the transducer array, and piezoelectric ceramic pillars are inserted into the reserved slots. The matching layer material is thenadhesived on the surface of the ceramic pillars.ResultsResultsResultsResultsThe measured performances of the transducer array agree well with the theoretical predictions. The operation frequency of the developed transducerarray is from 160kHz to 200kHz. The scanning angle is around 156 degree, and the maximum transmitting voltage response level is up to 191.9dB. Thecentral beam is suppressed over 12dB-15dB compared with the side beam. This system was applied to bottom imaging in some area of Qiandao Lake,and the result was consistent with that measured by single beam sonar for several times.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe work of this paper indicates that the piezoelectric ceramic pillar transducer with matching layer is suitable for high frequency broadband transducerdesign. Combining with the optimization technique of the transducer array’s line type, the desired directivity pattern for multi beam sonar can beachieved. The simulation technique introduced in this paper can also be applied to other transducer designs.

Keywords:Keywords:Keywords:Keywords: U-shape array; multi beam sonar; FEM



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ANALYSISANALYSISANALYSISANALYSIS OFOFOFOFTHETHETHETHE PERFORMANCEPERFORMANCEPERFORMANCEPERFORMANCEOFOFOFOFUNDERWATERUNDERWATERUNDERWATERUNDERWATERACOUSTICACOUSTICACOUSTICACOUSTIC PARAMETRICPARAMETRICPARAMETRICPARAMETRICARRAYARRAYARRAYARRAY

UNDERUNDERUNDERUNDER DIFFERENTDIFFERENTDIFFERENTDIFFERENT INPUTINPUTINPUTINPUT SIGNALSSIGNALSSIGNALSSIGNALS

Lin-lang BAI1,2 *1 Hangzhou Applied Acoustics Research Institute, Hangzhou 3100122 Science and Technology on Sonar Laboratory, Hangzhou 310012

*Corresponding author, E-mail: [email protected]; Tel.:0571-56782260

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAcoustic parametric array is a sound transmitting device which uses nonlinear effect of medium. It can generate difference frequency, sum frequencyand other second harmonics by using two high frequency ultrasonic primary sound waves propagating in the same direction. Along with thedevelopment of nonlinear acoustics in recent decades，as well as in the early 1960s Westervelt proposed the acoustic parametric array theory, acousticresearch had a great breakthrough that changed the conception of low-frequency sound waves can not form sharp directivity, The acoustic parametricarray not only has a good directivity, but also penetrativity. Through the previous study of the parametric array, This article analyze the performance ofunderwater acoustic parametric array under different input signals which include double-sideband modulatory signal, square root modulatory signal andsingle-sideband modulatory signal. It is hope to find a suitable input signal for the underwater acoustic parametric array.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe theoretical basis of acoustics parametric array is westervelt’s parametric array theory and Berktay’s far field solution. It shows that the differencefrequency pressure of parametric array is proportional to the envelope of the input signal the Berktay’s far field solution. The reproducing secondarysound is produced through two steps. The first must do the conversion from audio to ultrasonic. Next the ultrasonic is changed to audio by theself-demodulated in nonlinearly air. The second conversion can’t be control because of it depend on air. So the first conversion is very important. Andthe reproducing secondary sound field is special. So the theory and control technology of nonlinearly sound field was detailed researched. Theconclusion shows that there are direct relations between reproducing sound field and envelope shape. The single side band amplitude modulationmethod was proposed. For a single frequency signal the single sideband envelope is equal to ideal envelope. For multi-frequency signal the singlesideband envelope can be matched as closely as possible this ideal envelope by perfect frequencies, amplitudes and phases. In the case of low power,narrowband and no preprocessing, the SSB method can reproduce high-fidelity audio too.ResultsResultsResultsResultsThe article calculate the output pressure of parametric array which’s input signals are double-sideband modulatory signal, square root modulatory signaland single-sideband modulatory signal. In order to validate the calculated results, a 9-unit parametric array is designed and the relevant experiments arealso made. The calculated and experiment results show that single-sideband modulatory input signal has the narrow frequency band, thus the hetransducer’s facture difficulty of parametric array is play down, and the project power is economization. Approximating square root modulatory signalhas the lowest harmonious distortion, and single-sideband modulatory signal has the least harmornics as analyzing.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe input signals in the design of parametric arrays have been discussed. The experimentally obtained results were found to be in good agreement withthe theoretically expected performance. And the conclusions is:(1) The output pressure have the harmonious distortion whether the input signal is double-sideband modulated or single-sideband modulated, but the

latter is weaker and the output pressure is stronger;(2) The output pressure source level will augment with a large input power, but the power cannot too large to cause the nonlinear of the amplifier, at

this rate the harmonious distortion will boost up too.

Keywords:Keywords:Keywords:Keywords: acoustic parametric array nonlinear acoustic; transducer array directivity; conversion efficiency



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ANANANANANALYSISANALYSISANALYSISANALYSIS OFOFOFOFTHICKNESS-EXTENSIONTHICKNESS-EXTENSIONTHICKNESS-EXTENSIONTHICKNESS-EXTENSIONWAVESWAVESWAVESWAVES OFOFOFOFAAAA PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC PLATEPLATEPLATEPLATE

De-jin HUANG *, Xin-yi CHEN, Ji WANGSchool of Mech Eng & Mechanics, Ningbo University, Ningbo, Zhejiang 315211*Corresponding author, E-mail: [email protected]; Tel.: 0574-87600421

Thickness-extension vibration modes of pizoelectric plates are widely used as the working modes of transducers. First order two-dimensional plateequations governing the coupled extensional and thickness-extension motions of plates can be reduced to the classical equations of extension for lowfrequencies and long waves. It is shown in this paper, that for long waves with small wave numbers, and for frequencies very close to the fundamentalthickness-extension frequency, the two-dimensional plate equations for coupled extension and thickness-extension can be reduced to a single equationfor thickness-extension waves by properly eliminating the extensional displacements. The dispersion relation of the reduced equation is an asymptoticexpression of that of the original system near the fundamental thickness-extension frequency and the branch of the dispersion relations for theextensional motion of the original system disappears in the reduced equation. The resulting equations for the thickness-extension motion are valid forlong waves near the first thickness-extension frequency. The structure of the resulting equation suggests the existence of energy-trapping phenomenaassociated with thickness-extension vibrations. It is expected that the equations obtained above will be useful in analyzing transducers working withthickness-extension modes.

Keywords:Keywords:Keywords:Keywords: approximate analysis; thickness-extension wave; piezoelectric plate; dispersion relationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the State Key Program of National Natural Science of China(10932004), the Key Team ofTechnological Innovation of Zhejiang Province (2011R09025-02), the Natural Science Foundation of Zhejiang Province (LY12F01015), the KeyScientific Research Fund of the Department of Education of Zhejiang Province (Z201018143) and the Natural Science Foundation of Ningbo（2011A610183）.


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SH-SAWSH-SAWSH-SAWSH-SAWPROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININAAAA PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC STRUCTURESTRUCTURESTRUCTURESTRUCTUREWITHWITHWITHWITHVISCOELASTICVISCOELASTICVISCOELASTICVISCOELASTIC LAYERLAYERLAYERLAYER

Jing CUI, Jian-ke DU*, Ting-feng MA, Ji WANGSchool of Mechanical Engineering and Mechanics, Ningbo University,

818 Fenghua Road, Ningbo, Zhejiang 315211, China

* Corresponding author, E-mail: [email protected]; Tel.: 0574-8760-00924

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveIt is well known that shear horizontal surface acoustic waves (SH-SAWs) have wide applications in biosensing and chemical sensing fields, where thecells or DNA molecules are often modeled as a viscoelastic layer loaded on the piezoelectric substrate. Furthermore, the properties of receptive layer ofliquid sensor based on the piezoelectric acoustic waves often show viscoelasticity after absorbing some components. The change of viscoelasticity ofthe coating layer can lead to the shift in phase velocity or frequency, which is of importance for sensor applications. So it is necessary to analyzeSH-SAW in piezoelectric structures with consideration of both viscoelasticity of the sensitive layer and piezoelectricity of the substrate simultaneouslydue to the requirement of higher precision and accuracy in the biosensing measurement.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe focus on the effects of the viscosity of mass layer on the dispersion relations of the SH-SAWs in layered piezoelectric structures. An analyticalapproach is taken to investigate SH-SAW propagation in a viscoelastic/piezoelectric structure, where a thin viscoelastic layer is bonded to asemi-infinite piezoelectric substrate. The governing equations of waves are obtained on the basis of the linearly piezoelectric theory. The analyticalsolution of dispersion relations are obtained for mechanical and electrical open or shorted boundary conditions. The phase velocity is calculated andpresented. The distributions of the displacements and the shear stresses are also investigated and figured. The effects of the viscoelasticity on theproperties of the SH-SAWs are analyzed and discussed.ResultsResultsResultsResultsWe calculate the phase velocity based on the dispersive relations of SH-SAW in layered piezoelectric structures with consideration of viscosity of masslayer. The distributions of displacements and stresses are also obtained and presented. From the numerical results we can find that the phase velocitydecreases with the increase of the viscous coefficient, whereas the attenuation increases with the viscous coefficient. The displacements and the shearstresses increase with the decrease of the viscosity for both electrically open and shorted cases.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe numerical results show that the viscosity of the layer has obvious effect on SH-SAW propagation. The phase velocity decreases with the increaseof the viscous coefficient. It also can be seen that the attenuation increases with the viscosity of the layer, and the displacements and the shear stressdecrease with the increase of the viscous coefficient. From the results we can find that the effects of viscoelastic layer on SH-SAW propagation areremarkable. The method and results can be helpful for the design of the piezoelectric acoustic wave sensors or resonators.

Keywords:Keywords:Keywords:Keywords: SH-SAW; piezoelectric; viscoelastic; attenuationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Nos. 11072116 and 10932004), ZhejiangProvincial Science Fund for Distinguished Young Scholars (No.LR12A02001), K.C.Wong Education Foundation, Hong Kong and K.C.Wong MagnaFund in Ningbo University.



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GREENGREENGREENGREEN’’’’SSSS FUNCTIONFUNCTIONFUNCTIONFUNCTION FORFORFORFORANANANAN ELECTRICALLYELECTRICALLYELECTRICALLYELECTRICALLYPERMEABLEPERMEABLEPERMEABLEPERMEABLE CRACKCRACKCRACKCRACK ININININ

THERMOPIEZOELECTRICTHERMOPIEZOELECTRICTHERMOPIEZOELECTRICTHERMOPIEZOELECTRICMATERIALSMATERIALSMATERIALSMATERIALS

Ai-bing ZHANG1*, Bao-lin WANG1

1 Graduate School at Shenzhen, Harbin Institute of Technology, Harbin 150001


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveDue to rapid growth in applications, understanding of the fracture properties of piezoelectric materials in thermal-mechanical conditions becomes moreand more important. The analysis of the fracture process of these materials could provide useful information to improve the design of piezoelectricdevices operating in thermal environment. An important issue in studying fracture process of piezoelectric materials is the crack faces electric boundaryconditions. One commonly used boundary condition is the specification that the normal component of electric displacement along the crack facesequals to zero, i.e., the impermeable assumption. The other commonly used boundary condition treats the crack as being electrically permeable. For thepermeable crack model, the cracks are regarded as thin slits with permeable faces and thus the normal components of electric displacement and thetangential component of electric field are assumed to be continuous across the slit faces. It is found that the electric field and the electric displacementintensity factors depend only on the applied mechanical loads. It has been pointed out that the permeable crack assumption can be directly applied tothe fracture of piezoelectric materials in engineering applications if the crack interior is filled with conductive media. With the rapidly increasingapplications of piezoelectric materials in high temperature environment, it is very important to study the thermo-electric-elastic coupling fracturebehavior of these advanced materials. Some classical thermal fracture problems of piezoelectric materials have been treated by several investigators.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, the generalized 2D problem of thermo-piezoelectric materials containing a permeable crack is studied. The Green’s functions are obtainedfor the stress and electric displacement fields for an electrically permeable crack in a piezoelectric material subjected to a uniform electro-mechanicalload and a uniform heat flux at infinity. Stroh formalism and Green’s function method are used to reduce the problem to a set of singular integralequations which are solved in closed-form. When the crack is assumed to be traction free, the crack opening displacement must be negative betweenone half of the crack faces unless a sufficiently large tensile stress is superposed. Then, the permeable crack problem is reformulated by assuming a farfield tensile stress.

ResultsResultsResultsResultsThe crack opening condition is given by using the expression of the crack opening displacement when the far field tensile stress is superposed. Finally,Green’s function of the stress and electric displacement intensity factors at each crack tip are obtained. These results can be applied to the piezoelectricmaterials containing an electrically permeable crack problems under thermal-mechanical loading directly.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results show that the singularity of the stress and electric displacement depends only on the heat flux and the applied mechanical loads when theelectrically permeable crack is supposed. The electric displacement inside the crack is linearly variable, which is different from the results based on theimpermeable crack model. If the crack opening condition is not satisfied, a negative crack opening displacement is predicted near one of the crack tipsand a contact zone is anticipated between the crack surfaces. This is a partial contact problem and will be discussed in our future work.

Keywords:Keywords:Keywords:Keywords: piezoelectric materials; Green’s function; thermal stress; stress intensity factorsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Grant Nos. 10972067 and 11172081).



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AAAAMULTI-MODESMULTI-MODESMULTI-MODESMULTI-MODES CYLINDRICALCYLINDRICALCYLINDRICALCYLINDRICALPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC ROTARYROTARYROTARYROTARYMOTORMOTORMOTORMOTORWITHWITHWITHWITHAAAA

SINGLE-VIBRATORSINGLE-VIBRATORSINGLE-VIBRATORSINGLE-VIBRATOR

Bin HE, Kai XU, Zeng-ping XING*Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, P.R. China, 315201

* Corresponding author, E-mail: [email protected]; Tel: 15088832980

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric motor is a new type of actuator, which makes use of the converse piezoelectric effect and converts the ultrasonic vibration into rotational(or linear) motion by the frictional force. It has so many superior characteristics, such as high torque at low speed, quick response, high power/weightratio, high torque, efficiency insensitive to sizes, compact size, excellent controllability and simple structure, which are superior to the conventionalelectromagnetic motors in millimeter-order and sub millimeter-order. To miniaturize the USM, some types of piezoelectric motor were designed, suchas disk type and cylindrical type. The application of the micro piezoelectric motor is increasing year by year, such as in microsurgery, insect scaledrobots and micro-positioning stages.Most cylindrical type and disk type piezoelectric motor excite at least two orthogonal resonance modes to obtain an elliptic motion on the stator surface,and most of them require two orthogonal driving signals. Recently, some types of piezoelectric motor which used only one driving signal wasdeveloped. Clearly, motors can be significantly miniaturized by simplifying their structures and using only a single-phase driving circuit, especiallyusing only one vibrator.Our aim of this work is to design a single-vibrator multi-modes cylindrical piezoelectric motor, which achieves the bidirectional rotations by changingthe driving frequencies. This type piezoelectric motor structure has a high potential for miniaturization due to the simple structure and easy control.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe stator of the motor consists of a brass tube, whose outside surface was flattened on two sides at 90 degrees to each other, on one of which onepiezoelectric plate was bonded. Due to the unsymmetrical structure design, the stator has two split degenerated orthogonal bending mode, whoseresonance frequencies are close to each other. And only one piezoelectric plate can excite the two degenerated bending modes around the bending moderesonant frequency to couple to an elliptical motion at the end of the stator, and the rotator generates rotation through the frictional force. If the motorcan generated the reverse directional rotation at another bending mode resonant frequency, it would achieve the bidirectional rotations by changing thedriving frequency.The result of the finite element analysis and theoretical analysis show that the bending modes’ shapes and resonant frequencies will change with thedifferent width of the outside flattened surface, which is the one without piezoelectric plate, and the unsymmetrical structure design can achieve thebidirectional rotation by changing the frequency from the second bending mode to the third bending mode.The stator of the prototype motor consists of a brass tube with an outer diameter of 6 mm, an inner diameter of 4 mm, a length of 26 mm, and apiezoelectric plate with dimensions, 25 mm in length, 4 mm in widen, and 0.5 mm in thickness. The width of the one outside flattened surface is 4mm,which was bonded with the piezoelectric plate. The finite element analysis and theoretical analysis indicates that the motor can generated clockwiserotation at the driving frequency around the second bending mode, and anticlockwise at the driving frequency around the third bending mode, and theresult also indicates the width of outside surface without piezoelectric plate is 3.55 mm will make motor rotate well.ResultsResultsResultsResultsThe prototype motor can rotate clockwise at a driving frequency of ~22.208kHz and anticlockwise at a driving frequency of ~51.605kHz. The motorachieved a maximum speed of 840 rpm, and the rotational speed illustrated linearity versus the driving voltage. So the motor achieves the bidirectionalrotation by changing the driving frequencies.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe result of the testing confirms the concept of the single-vibrator multi-modes rotary cylindrical piezoelectric motor and the deduction of the finiteelement analysis and theoretical analysis, which can be used to design and optimize the piezoelectric motor. The motor choose the second and the thirdbending modes as the working modes, but the difference of the frequency between the two modes is too large, which complex the driving circuit, andthe clockwise speed is 3 times of the anticlockwise one, so the following work is to decrease the difference of the frequency and rotation speed. Thistype piezoelectric motor structure has a high potential for miniaturization due to the simple structure and easy control.

Keywords:Keywords:Keywords:Keywords: piezoelectric motor, single vibrator, bidirectional rotation, ultrasonic motorAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported by NSFC (Grant No. 11004207) and Ningbo Science and Technology Innovation Team (GrantNo. 2011B82004).



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ELECTROELASTICELECTROELASTICELECTROELASTICELECTROELASTICWAVEWAVEWAVEWAVE PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININAAAA FGMFGMFGMFGM SANDWICHSANDWICHSANDWICHSANDWICHCIRCULARCIRCULARCIRCULARCIRCULAR PLATEPLATEPLATEPLATEWITHWITHWITHWITH

PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC LAYERSLAYERSLAYERSLAYERS

Hong-liang DAI1,2*, Xiang YAN1,2

1State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,Hunan University, Changsha 4100822Department of Engineering Mechanics, College of Mechanical & Vehicle Engineering, Hunan University, Changsha 410082


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveWith the development of science and technology, more and more scholars attach importance to the study of new materials. Because piezoelectricmaterials which suffer external pressure can generate voltage at its both ends, it is widely used in sensor and drive field, and people pay much attentionto its theoretical research, especially, for the study of new piezoelectric materials, such as electroelastic wave propagation in the FGM circular platewith piezoelectric layers.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsUtilizing the Finite Difference Method and Newmark Method, the electroelastic wave propagation in a FGM sandwich circular plate with piezoelectriclayers is investigated. Based on the first-order shear deformation theory and the geometry nonlinear relationship, the nonlinear motion control equationsof the FGM sandwich circular plate with piezoelectric layers are formulated by using Hamilton’s principle, combining with boundary and initialconditions, the numerical solutions are presented by adopting iterative method.ResultsResultsResultsResultsThrough some specific numerical examples, the paper discusses the geometric parameters, volume fraction index, mechanical and electric load whichhave different influence on electroelastic wave propagation in the FGM sandwich circular plate with piezoelectric layers.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe bending stiffness of the FGM sandwich circular plate with piezoelectric layers subjected to a simple harmonic excitation is reduced as the volumefraction index increases, then its deformation becomes larger and larger.The magnitude of the radius stress for the mid-point of the FGM sandwichcircular plate with piezoelectric layers decreases as the the ratio of thickness and radius, the piezoelectric layer’s thickness increases, and the changetrend of normal stress is contrary. When the impact load is eliminated, the initial deflection of the FGM sandwich circular plate with piezoelectriclayers reaches maximum, and then it will be into a free vibration, and the amplitude of the free vibration for the FGM sandwich circular plate decreasesas the the ratio of thickness and radius and volume fraction index increases, and the frequency is also reducing.

Keywords:Keywords:Keywords:Keywords: electroelastic wave; FGM; sandwich circular plate; piezoelectric layerAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11072077).



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PIEZOELECTRETS:PIEZOELECTRETS:PIEZOELECTRETS:PIEZOELECTRETS: POLYMERPOLYMERPOLYMERPOLYMER FOAMSFOAMSFOAMSFOAMS FORFORFORFORTRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCERAPPLICATIONSAPPLICATIONSAPPLICATIONSAPPLICATIONS

Peng FANG*, Guang-lin LIThe Key Lab of Health Informatics of Chinese Academy of Sciences (CAS),Shenzhen Institutes of Advanced Technology, CAS, Shenzhen 518055


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric materials are commonly used in various sensors and actuators. Besides the traditional piezoelectric ceramics such as Lead ZirconateTitanate and polar piezoelectric polymers such as β-phase Polyvinylidene Fluoride, piezoelectrets have recently become a new group of piezoelectricmaterials. Piezoelectrets are functional polymer systems for electromechanical transduction, with elastically heterogeneous cellular structures andinternal quasi-permanent dipole moments. The piezoelectricity of piezoelectrets stems from linear changes of the dipole moments in response toexternal mechanical or electrical stress. Compared with the traditional piezoelectric materials, piezoelectrets own several desirable advantages. In thispaper, the preparation processes and the properties of piezoelectrets were introduced and then how to enhance the performance of piezoelectrets werediscussed. Finally, some promising applications of piezoelectrets were proposed.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe structures and therefore the preparation procedures of piezoelectrets are quite different from those of piezoelectric ceramics and polar piezoelectricpolymers. Piezoelectrets are heterogeneous polymer/gas systems, i.e. they are polymeric cellular foams with macroscopic voids. Several polymers aregood candidates for piezoelectret applications, among which Polypropylene (PP) foam is the most prominent one up to now. In addition,Polyethylene-naphthalate (PEN) foam is newly developed for possible property improvements. The cellular structures, with very low elastic stiffness,are very essential for piezoelectricity. They are usually prepared with a combination of foaming and gas-diffusion-expansion at elevated pressures andtemperatures. Thereafter, a controlled biaxial-stretching is applied in order to adjust the structure and achieve lens-like voids. Moreover, in a chargingprocess, the internal dipole moments are formed by separated and trapped charges due to gas-breakdown, which is generated by high electric fieldsacross the voids. Finally, polymer foams are deposited with metal electrodes on both outer surfaces. Piezoelectricity of piezoelectrets can be determinedmechanically or acoustically. In a mechanical measurement, a dynamic stress is applied and the charges generated by the sample are measured. In anacoustical measurement, sample performs as a microphone, where sound pressure is applied and the resulted electric signals are analyzed.ResultsResultsResultsResultsPiezoelectrets have stronger lengthways piezoelectricity, whereas they show much weaker crosswise one. After the optimization of cellular structuresand charging processes, the PP-foam piezoelectrets may exhibit piezoelectric d33 coefficients of 600 pC/N and more. The d33 coefficients stronglydepend on the elastic stiffness of foam as well as the structure morphology. The samples with small voids are relatively stiff and show low d33. Acontrolled increase of void height by gas-diffusion-expansion can decrease stiffness and increase d33. Too large a void height, i.e. more spherical void,however, causes a large stiffness as well, and lowers d33. The operating temperature of PP-foam piezoelectrets can not be much higher than 60 °C. Thenewly developed PEN-foam piezoelectrets show better d33 thermal stabilities up to 80-100 °C, but usually come at the price of smaller d33 values ofaround 200 pC/N. Charging at elevated temperatures or annealing after charging may improve thermal stabilities. The samples charged at properelevated temperatures show operating temperatures as high as 110-120 °C, but smaller d33 values. Acoustical measurements exhibit that, piezoelectretsare suitable for not only electro-mechanical, but also electro-acoustical applications. In a wide frequency range from 70 Hz to 20 kHz, PP-foampiezoelectret microphones show sensitivity of around 58 dB and very flat frequency response.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsMany previous works, including this study, have discussed and confirmed the desirable performances of piezoelectrets. Polymer films are thin, flexible,and light weight, and therefore can be fabricated into any size and shape. For example, piezoelectret transducers can be installed on curved surfaces. Inaddition, they are relatively inexpensive and can be easily processed with present techniques. The relative small specific acoustic impedance ofpiezoelectrets is another strong point in transducer applications. Compared with ceramics, the impedance of polymers is much closer to that of waterand human skin. As a consequence, piezoelectrets can emit a larger portion of acoustic energy generated in an underwater sound source, or collecthuman internal vital signals directly at skin surfaces. Furthermore, it is also a significant advantage over most classical piezoelectrics that the majorityof cellular polymers consist of nontoxic constituents, which makes them very suitable for use in biomedical devices. Several applications based onpiezoelectrets, including microphones, ultrasound transducers, keyboards, tactile sensors, and vital signs monitoring systems, have been suggested.Future works will mainly focus on the performance improvements of piezoelectrets and explore more application developments as well.

Keywords:Keywords:Keywords:Keywords: piezoelectricity; piezoelectret; transducer; polymerAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was supported in part by the Shenzhen Governmental Basic Research Grand (#JC201005270295A), theShenzhen Public Platform for Biomedical Electronics and Health Informatics, and the Guangdong Innovation Research Team Fund for Low-costHealthcare Technologies.



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EFFECTSEFFECTSEFFECTSEFFECTS OFOFOFOFAAAA BIASINGBIASINGBIASINGBIASING ELECTRICELECTRICELECTRICELECTRIC FIELDFIELDFIELDFIELDONONONONRAYLEIGHRAYLEIGHRAYLEIGHRAYLEIGHWAVESWAVESWAVESWAVES ININININMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRIC

STRUCTURESSTRUCTURESSTRUCTURESSTRUCTURES

Li-li YUAN1, 2, Jian-ke DU1*, Ji WANG1

1School of Mechanical Engineering and Mechanics, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 3152112School of Architectural, Civil Engineering and Environment, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211

*Corresponding author, E-mail: [email protected]; Tel.: 0574-8760-00924

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveIt is well known that the magnetoelectric composite materials have important applications in resonators, sensors, and actuators, etc. These materialsconsisting of a piezoelectric phase and a piezomagnetic phase have magnetoelectric effect that is not present in single-phase piezoelectric orpiezomagnetic materials. The properties of surface acoustic wave (SAW) in the magnetoelectric structures can be affected by the biasing electric fields,biasing magnetic fields, initial stresses, etc. It is of importance to analyze the effects of these fields on the SAW propagation for the design of acousticwave devices. We here focus on the effects of the biasing electric on the Rayleigh waves in the layered magnetoelectric structures.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsPropagation of Rayleigh surface acoustic waves in a layered magnetoelectric structure under a biasing electric field is studied analytically. Based on thelinearly magneto-electro-elastic theory, the coupling wave equations are obtained and solved with consideration of a biasing electric field formagnetoelectrically open and shorted conditions, respectively. The dispersion relations are calculated and figured. The effects of a biasing electric fieldon phase velocity, stresses and displacement are presented and discussed in detail.ResultsResultsResultsResultsThe phase velocity versus biasing electric fields can be obtained by solving the dispersive relation using Matlab software. From the results we can findthat the effects of the biasing fields on the properties of Rayleigh waves are remarkable. It can be seen that the phase velocity decrease with thenon-dimensional wave number, and increase with the biasing electric field. It can also be seen that the phase velocity decrease with the ratio ofthickness to wavelength.

Fig.1 Phase velocity of the first order Fig.2 Displacement distribution

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe propagation of Rayleigh waves in a magnetoelectric structure is investigated with consideration of a biasing electric field. The dispersion relationof Rayleigh waves is obtained and solved. Numerical results show that the phase velocity is sensitive to the biasing electric field, and the displacementand stress fields can also be affected by the biasing electric field. These analytical method and the results are useful for the design of themagnetoelectric resonators and sensors.

KeywordsKeywordsKeywordsKeywords: rayleigh waves; piezoelectric; piezomagnetic; biasing electric fieldAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Nos. 11072116 and 10932004), ZhejiangProvincial Science Fund for Distinguished Young Scholars (No.LR12A02001), K.C.Wong Education Foundation, Hong Kong and K.C.Wong MagnaFund in Ningbo University.



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AAAA STUDYSTUDYSTUDYSTUDYONONONONAIRBORNEAIRBORNEAIRBORNEAIRBORNE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC TRANSDUCERSTRANSDUCERSTRANSDUCERSTRANSDUCERS

Sheng ZHOU1, Chao CHEN 2*

1 State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China2 State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveOver the last decades, noncontact and air-coupled ultrasonic techniques have experienced an enormous impetus. The airborne transducers show greatpotential and applications in NDT owing to its no harm to the test materials and more convenient scanning relative to the traditional ultrasonic testing.But because of the huge mismatch between air and the piezoelectric ceramics, it is difficult to get high sensitive and wide-band transducers. In additionthe signal to noise ratio（SNR）is extremity low and the efficiency either. Here we need to use focused air-coupled ultrasonic transmitter to simulate thewild blasting so that researchers can use ultrasound to analyze the model of geological structure in a lab environment. Toward this end, we want to finda way to deal with the above problems and provide some guidance and help for the production of such air-coupled transducers.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe purpose of this work is twofold: one is to investigate and contrast some potential materials to produce impedance matching layers for airbornepiezoelectric transducers. Here we have taken two matching layers, the first matching layer closed to the piezoelectric material was made by epoxyresin and the second matching layer closed to the air was manufactured by a set of filtration membranes or silica aerogel which both show lowimpedance and great acoustic performance for producing airborne ultrasonic transducers; On the other hand, we use 1-3 connectivity piezoelectriccomposites to substitute the traditional piezoelectric materials to get better bandwidth and impedance matching.ResultsResultsResultsResultsThrough methods above, we manufactured a series of airborne ultrasonic transducers. Experiments show that the efficiency of noncontact piezoelectricultrasonic transducers depends on the parameters of the matching layers and the bonding process, especially the materials, pore size and the thicknessfor the filtration membranes and characteristics of the silica aerogel. By properly selecting the matching layers and the process, the airborne transducerscan achieved a good performance for NDT or the detection of the geological model structure.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn view of great application prospects of air-coupled piezoelectric ultrasonic transducers, more work should be done in the future. The above methodsalso exist some shortcomings and difficulties. An additional matching layer will be draw into due to the binder and the silica aerogel is difficult toprocess forming.

Keywords:Keywords:Keywords:Keywords: piezoelectric transducer; airborne; matching layerAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 50975135); Specialized ResearchFund for the Nanjing University of Aeronautics and Astronautics（No.NJ2011001）.At last, the authors wish to thank the help and support provided bythe Sinopec Geophysical Research Institute in Nanjing.

[email protected]


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LARGELARGELARGELARGETIME-BANDWIDTHTIME-BANDWIDTHTIME-BANDWIDTHTIME-BANDWIDTH PRODUCTPRODUCTPRODUCTPRODUCTULTRASOUNDULTRASOUNDULTRASOUNDULTRASOUNDGENERATIONGENERATIONGENERATIONGENERATION BYBYBYBYDRIVINGDRIVINGDRIVINGDRIVING

PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICTRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCER

Han ZHANG*, Zhi-wu AN, Xiao-min WANG, Jie MAO,Guo-xuan LIAN, Ming-xuan LIInstitute of Acoustics, Chinese Academy of Sciences, Beijing 100190


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThis paper presents an investigation into the large time-bandwidth product (TBWP) ultrasonic signals. This will aid in optimizing the ultrasound, whichis widely applied to provide information or energy in medical diagnostic and therapy, industrial testing and processing, oil exploration and so on. Theaim is to generate large TBWP ultrasonic signals that can simultaneously improve axial resolution and penetrating power.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsDifferent from radar signal, there are two major difficulties in the generation of large TBWP ultrasonic signal by using piezoelectric transducer. One isthe transduction mechanism including surface transduction and acousto-electrical regeneration; the other is the limited bandwidth of the transducer. Toovercome the difficulties, an adaptive filtering algorithm was used to modify a linear frequency modulation (LFM) signal. Then a large TBWPultrasonic signal was generated by a thickness-mode transducer. We compute the process with Mason equivalent circuit method and calculate threeother cases of commonly-used electrical signals. Experiments were also carried out to demonstrate its advantages and applicability.ResultsResultsResultsResultsIn the respective experiments, ultrasonic signals are generated by a LFM signal directly or a signal computed for the same TBWP. With comparison,the latter is shown much better in the linear time-frequency relation( Figure 1), waveform and bandwidth. And this computed method is quite useful fordetecting the debonding between a high attenuation rubber block and a steel plate.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe larger TBWP ultrasonic signal can be generated by driving a piezoelectric transducer with a signal computed by using an adaptive filteringalgorithm. Experimental results show that better axial resolution and higher power are achieved simultaneously. It is expected that this new techniquemay play an important role in NDT&E in future.

Figure 1. Time frequency representation of ultrasonic wave generated by a piezoelectric transducer under different driving signal, a: a LFM signal; b: a modified LFM signal.

Keywords:Keywords:Keywords:Keywords: piezoelectric transducer; large time bandwidth product; modified linear frequency modulation signalAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work is supported by the National Natural Science Foundation of China (Nos.10834009, 11074272).


app:ds:exploration


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AAAATHICKNESS-SHEARTHICKNESS-SHEARTHICKNESS-SHEARTHICKNESS-SHEARMODEMODEMODEMODE RESONATORRESONATORRESONATORRESONATORWITHWITHWITHWITHAAAA FERROELECTRICFERROELECTRICFERROELECTRICFERROELECTRIC INVERSIONINVERSIONINVERSIONINVERSION LAYERLAYERLAYERLAYER

Ting-feng MA 1*, Ji WANG 1, Jian-ke DU1, Zhi-tian ZHANG2, Chao ZHANG2

1 Piezoelectric Device Laboratory, School of Mechanical Engineering and Mechanics, Ningbo University, Ningbo 315211, China2 Research Institute of Tsinghua University in Shenzhen, Shenzhen 518057, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePrevious investigations showed that a local domain inversion takes place when bare LiNbO3 plates undergo heat treatment at temperatures higher than1070°C, which is the Curie point of LiNbO3 crystal. Experimental results also showed that the inversion layer grows gradually and the domainboundary ultimately stops at the middle plane of plate for a sufficiently long heat treatment. For an inversion layer, the piezoelectric constants areopposite in sign to those of a regular layer. It is found that an electric field can excite even-order thickness-extensional modes as well as odd-ordermodes, which has been applied in high frequency ultrasonic transducers.The researches on the application of the inversion layer piezoelectric device mainly focused on high frequency ultrasonic transducers working on thethickness-extensional mode. The research on the inversion layer device working on the thickness-shear mode has not been reported. In this work,several experiments were done to investigate the characteristics of the inversion layer device working on the thickness-shear mode.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsTo obtain an inversion layer, (yxl)-58°LiNbO3 substrates were annealed as follows: Crystal substrates were placed in a high temperature tube furnace(HTRH–VS, Nabertherm Ltd), and then the furnace was set to heat up to 1170°C with a heating rate of 40°C /min, and was kept at this temperature forone hour. The next step is to set the furnace to decrease its temperature with a cooling rate of 40°C /min. Finally, gold electrodes were made by vacuumevaporation on the same surface of (yxl)-58°LiNbO3 substrate to form a LFE (Lateral Field Excited) resonator. The electrical impedances of the(yxl)-58°LiNbO3 LFE devices were measured using an impedance analyzer (Agilent 4294A, Agilent Technologies Ldt).ResultsResultsResultsResultsFor the annealed (yxl)-58°LiNbO3 LFE device, in addition to the resonance corresponding to the fundamental mode, there appears another resonancepeak due to the 2nd harmonic of LFE c-mode. Most importantly, the second resonance peak is very clean, with very small additional oscillations whichindicates little presence of spurious modes.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results show that the inversion layer can suppress spurious modes significantly. An inversion layer of half the thickness of the plate can be formedafter the crystal plate has been annealed for a sufficiently long time. It seems that two crystal layers with opposite polarities are bonded together. Thusthe even-order harmonic modes can be excited by electric field easily. Since the polarities of the two crystal layers are opposite, the odd-order harmonicmodes can be suppressed to a large extent. For the thickness-shear resonator, the spurious modes mainly result from the coupling between thethickness-shear mode and overtones of the thickness-flexural mode. For thickness-shear vibrations, the odd-order harmonic modes have antisymmetricdisplacement directions on both sides of the middle plane of the plate, which is similar to that of the thickness-flexural mode. Thus, the odd-orderthickness-shear modes tend to couple with the thickness-flexural modes. While the even-order thickness-shear harmonic modes have symmetricdisplacement directions on both sides of the middle plane of the plate, which is different to that of the thickness-flexural mode. Therefore, the couplingbetween even-order thickness-shear harmonic modes and the thickness-flexural modes is very weak. Thus a resonator with an inversion layer operatingwith the 2nd thickness-shear harmonic can avoid spurious modes related to thickness-flexural mode.In this work, LiNbO3 LFE bulk acoustic wave devices with a ferroelectric inversion layer working on the thickness-shear modes were studied. It isfound that the inversion layer can suppress spurious modes effectively. Previous researches showed that LFE bulk acoustic wave sensors made frommaterials with higher piezoelectric coupling factors have higher sensitivity. LFE piezoelectric coupling factors of LiNbO3 crystal are more than 10times higher than those of the traditional quartz crystal. However, bulk acoustic wave devices based on materials with high piezoelectric couplingfactors tend to have many spurious modes. This lowers the frequency stability of the devices seriously and results in limitations in their applications,especially in high-sensitivity sensors. Through the analysis of the above results, it is shown that the inversion layer can suppress spurious modes ofLiNbO3 LFE devices working on thickness-shear modes effectively. Therefore, thickness-shear mode resonators using LiNbO3 plates with an inversionlayer have a good application prospect in high-sensitivity sensors.

Keywords:Keywords:Keywords:Keywords: resonator; thickness-shear mode; ferroelectric inversion layer; LiNbO3

Acknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is funded by the open fund of Zhejiang provincial top key discipline and the National Natural ScienceFoundation of China (Nos.11072116 and 10932004).


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SELFSELFSELFSELFASSEMBLYASSEMBLYASSEMBLYASSEMBLYPARTICLESPARTICLESPARTICLESPARTICLES USINGUSINGUSINGUSING PHONONIC-CRYSTALPHONONIC-CRYSTALPHONONIC-CRYSTALPHONONIC-CRYSTALSLABSSLABSSLABSSLABS

Qian WU 1,2, Fei-yan CAI 1#, Hai-rong ZHENG1*

1Shenzhen Institutes of Advanced Technology, Chinese Academy of Sciences. Shenzhen 5180552Department of physics, Jilin University. Changchun 130000

*Corresponding author, E-mail: #[email protected]; *[email protected]; Tel.: 0755-86292268

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSelf-assembly methods have been used to construct complex materials. In field of optic, photonic crystal slab has been introduced to realize opticallyreconfigurable template. While in acoustics aspect, there is little related research. Here we consider how acoustic radiation forces can be used to directassembly and reconfiguration of particles contactless and noninvasive on a three-dimensional phononic crystal slab.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe system we consider is a phononic crystal slab immersed in water. The PMMA slab is constructed with periodic array of holes. Acoustic wavewould propagate the phononic crystal slab from below. We calculate the transmission through the slab numerically using the finite-differencetime-domain (FDTD) method and we calculate the force on spheres. The centre of the sphere is placed above the slab surface. The calculation is donein an unit cell that includes one period of the phononic crystal slab. Periodic boundary conditions are used in the lateral directions and radiationboundary conditions are used in the top and the bottom.ResultsResultsResultsResultsLocal resonance field can be excited. Each unit of phononic crystal can capture and exclude particles.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsPhononic crystal structure can be used to realize self-assembly particles.

Keywords:Keywords:Keywords:Keywords: phononic crystal; self-assembly; acoustic radiation forceAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by National Science Foundation(Grant Nos. 10904095, 10904094, 61020106008, 81027006,61031003), National Basic Research Program 973 (Grant Nos. 2011CB707903 and 2010CB534914) from Ministry of Science and Technology, China.


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EQUIVALENTEQUIVALENTEQUIVALENTEQUIVALENTCIRCUITCIRCUITCIRCUITCIRCUITMODELMODELMODELMODELWITHWITHWITHWITHTIME-VARYINGTIME-VARYINGTIME-VARYINGTIME-VARYING PARAMETERSPARAMETERSPARAMETERSPARAMETERS FORFORFORFORAAAATRAVELLINGTRAVELLINGTRAVELLINGTRAVELLING

WAVEWAVEWAVEWAVE ULTRASONICULTRASONICULTRASONICULTRASONICMOTORMOTORMOTORMOTOR

Wei-jia SHI *, Hui ZHAO, Yu YAOControl and Simulation Center, Harbin Institute of Technology, Harbin 150001


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe ultrasonic motor (USM) is a new type of actuator, which utilizes mechanical vibrations of its stator to drive the rotor though frictional forcesbetween the interface of the stator and the rotor. The ultrasonic motor has lots of advantages, such as large torque to volume/mass ratio, high holdingtorque in the absence of power supply. These advantages make an ultrasonic motor a good alternative to other electromagnetic counterparts in varyingapplications.However, the development of an ultrasonic motor for many applications has been limited, primarily due to lack of a detailed model. Generally speaking,the Equivalent Circuit Model (ECM) has been widely used to simulate the performance of the ultrasonic motor and to design the drive since 20thcentury. The ECM is weak in mechanism analysis, especially in the analysis of the interface; however, it provides a more easily understoodconstruction and is more suitable for the drive design. Therefore, the majority of the ultrasonic motor models are derived as equivalent circuit models.The majority of the ECMs neglected to consider the time-varying characteristics of the ultrasonic motors. However, these characteristics cannot beignored, which is proved by various experimental results. Hence, the drive, which is design based on the ECMs without the time-varying characteristics,may not keep the motors at the best operating point all the time.Therefore, the objective of this paper is to propose a novel ECM with time-varying parameters. The novel ECM will be used to optimize the overalldrive performance by simulation and to develop suitable control strategies for the drive; what’s more, it can describe the time-varying characteristics ofthe ultrasonic motors.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA.A.A.A. AAAA straightforwardstraightforwardstraightforwardstraightforward ECMECMECMECM ofofofof thethethethe ultrasonicultrasonicultrasonicultrasonic motormotormotormotor isisisis proposed.proposed.proposed.proposed. In this paper, we built a novel ECM which includes three elements: the stator, thecontact zone and the rotor. The whole ECM is obtained by connecting the three independent circuit models one by one. The details are described asfollow:a. The forced-vibration electrical model of the stator is built, based on the existing free-vibration circuit model which is called Mason circuit, byconsidering the rotor effect. The outputs of this part are the voltages which are related to the normal forces between the stator and the rotor. Weobtained the relationship between the voltages and the normal forces by utilizing the mechanical-electrical coupling equation.b. The model of the contact zone is built with the help of the Coulomb friction model. The driving friction forces are equal to the frictional factor andthe normal pressure. And the normal pressure is calculated by using the proposed ECM of the stator. The output of this part is the driving forces thatcan rotate the rotor.c. The model of the rotor is built based on the dynamical equation of the rotor. Theoretically speaking, take the difference of the driving force and theload force and divide by the moment of the inertia of the rotor, then we can get the angular acceleration. The ECM of the rotor follows the same role;however, the form of the model of the ECM is slightly different comparing with mathematical model. The forces are described by voltages and theangular velocity is described by current in the capacitance whose value is equal to the value of the moment of the inertia.B.B.B.B. TheTheTheThe novelnovelnovelnovel ECMECMECMECM cancancancan describedescribedescribedescribe thethethethe time-varyingtime-varyingtime-varyingtime-varying characteristicscharacteristicscharacteristicscharacteristics ofofofof thethethethe USM.USM.USM.USM. The time-varying characteristics of the USM include the two aspects,as follow: the temperature-resonance frequency characteristic and the temperature-time characteristic. The former one is decided by the last one. Hencethe parameters of the three sub-models are as functions of time and drive frequency to describe the time-varying characteristics of the USM. Theparameters include static capacitances, dynamic capacitances, dynamic resistances, dynamic inductances and the friction coefficient and so on. Theexpressions of the variables are obtained by various experiments.ResultsResultsResultsResultsThe simulations and experiments were taken. The expressions of the parameters are obtained from various data with the help of the experimental bench.And then the correctness of the proposed ECM is demonstrated by the experiment.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe novel equivalent circuit model which seems to be more convenient to be used in a drive circuit design and the motors characteristics simulations;what’s more it can describe the time-varying characteristics of the ultrasonic motor with the varying parameters. Hence, the drive which is designedfrom the novel model would be more practical.

Keywords:Keywords:Keywords:Keywords: traveling wave ultrasonic motor; equivalent circuit model; time-varying parameters


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ANANANAN EFFICIENTEFFICIENTEFFICIENTEFFICIENTHIGHERHIGHERHIGHERHIGHERORDERORDERORDERORDER ZIGZAGZIGZAGZIGZAGZIGZAG THEORYTHEORYTHEORYTHEORYFORFORFORFOR PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC ANDANDANDAND

PIEZOMAGNETICPIEZOMAGNETICPIEZOMAGNETICPIEZOMAGNETIC COMPOSITECOMPOSITECOMPOSITECOMPOSITE ANDANDANDAND SANDWICHSANDWICHSANDWICHSANDWICH BEAMSBEAMSBEAMSBEAMS

Long ZOU1, Hui-ming WANG2*

Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027

* Corresponding author, E-mail: [email protected]; Tel.: 18868819031

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric and piezomagnetic materials have been developed quickly in recent years. They are widely used in the composite structure as sensors andactuators because of its special coupling effect .So it is necessary to give their accurate result of displacement and stress field. But the exact result isvery complicated to obtain, then a approximate zigzag theory is provided for it.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsUse the third order zigzag model to give out the approximation for axial displacement across the thickness, which is a layerwise representation of theelectric and magnetic field. The electric and magnetic potential are approximated as piecewise linear across the sub-layers. Interfacial continuity of theinplane displacement and the transverse shear stress and traction free condition on the top and bottom are ensured under generalmagnetoelectromechanical loading situation.Then we use the variation principle to derive the governing equations and obtain the results at last.ResultsResultsResultsResultsConsidering a simply-supported beam with a piezoelectric layer on the top and a piezomagnetic layer on the bottom, we obtain the approximate resultsof the displacement, stress, electric and magnetic potential under general loading situation with the third order zigzag theory. Making somecomparisons with the exact and finite element results, then we have seen that it is an efficient and accurate way to analyse the composite and sandwichbeams.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsA efficient high order zigzag theory has present for the composite and sandwich beams.When undering the effect of electric or magnetic potential, themechanical lateral strain is ignored. It is reasonable, because it is much smaller than the potential strain.To obtain a more accurate result, we must makeappropriate more sub-layers for the beam.

Keywords:Keywords:Keywords:Keywords: zigzag theory ; composite and sandwich beam; piezoelectric; piezomagneticAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work is done under the advice of my tutor Professor Wang, he give me the most constructive and usefulsuggestions.Thanks for his help.



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EXACTEXACTEXACTEXACTANALYSISANALYSISANALYSISANALYSIS OFOFOFOFTHETHETHETHEDYNAMICDYNAMICDYNAMICDYNAMIC PROPERTIESPROPERTIESPROPERTIESPROPERTIES OFOFOFOF2-22-22-22-2 CEMENTCEMENTCEMENTCEMENT BASEDBASEDBASEDBASED

PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICACTUATORACTUATORACTUATORACTUATORCONSIDERINGCONSIDERINGCONSIDERINGCONSIDERING POLINGPOLINGPOLINGPOLING LAYERLAYERLAYERLAYEREFFECTEFFECTEFFECTEFFECT

Tao-tao ZHANG1*, Zhi-fei SHI2

1 School of Transportation Science and Engineering, Beihang University, Beijing, 100191, P. R. China

2 School of Civil Engineering, Beijing Jiaotong University, Beijing, 100044, P. R. China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveCement based piezoelectric composites can have both low frequency and good compatibility with concrete, which is helpful for measuring theproperties of civil engineering structures compared with other smart materials. Therefore, the cement-based piezoelectric composites plays an importantrole in the development of intelligent structures in civil engineering fields. However, till now, the research of the cement based piezoelectric compositeis still at the early stage and most works are focused on the fabrication and experiment of the cement based piezoelectric composite. Up till now therehave been only a few literatures dealing with the theoretical analysis of cement based piezoelectric composite, especially for the 2-2, 0-3 and 1-3cement based types. In the present work, the exact solutions of the dynamic behavior of 2-2 cement-based piezoelectric actuator were investigatedunder the harmonic electric signal while considering the poling layer between the cement layer and the piezoelectric layer.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe analytical model was established for the dynamic properties of 2-2 cement based piezoelectric transducer based on the actual engineeringrequirement in the first part of this study. The actuator consists of 2 cement layers (#1 and #5) and 1 piezoelectric layer (#3). In order to be closer to thereal condition, the adhesive layers (#2 and #4) which acts as an elastic layer between the cement layer and the piezoelectric layer are considered.Between the upper and lower surfaces of the piezoelectric layer, there is an external sinusoidal electrical potential V (Figure 1). By using thedisplacement method, exact solutions under the sinusoidal electric signal were obtained for the components of the displacement and stress of eachpiezoelectric layer and each cement layer respectively.ResultsResultsResultsResultsBy using the displacement method, the exact solutions were obtained for the components of the displacement and stress of each piezoelectric layer andeach cement layer respectively under the sinusoidal electric signal.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe second part of the study is focused on the comparisons and discussions with the FEM results. It was found that the numerical results obtained fromthe analytical solution are consistent with FEM results, therefore proving the validity of this study. Besides, other conclusions of the transducer understudy are given. The influence of the frequency for the displacement, the thickness of the poling layers and potential of the piezoelectric layer were alsodiscussed. Finally, it can be seen that the analytical model established in this paper works very well, which could benefit the design of this kind of smartdevices.

Keywords:Keywords:Keywords:Keywords: 2-2 cement based; poling layer effect; piezoelectricity; dynamic; exact solutions; actuator; comparison with FEM resultAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 50908007 and 51072018).


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RESEARCHRESEARCHRESEARCHRESEARCHOFOFOFOFTHETHETHETHE INFLUENCEINFLUENCEINFLUENCEINFLUENCE ONONONONMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRIC EFFECTEFFECTEFFECTEFFECTBYBYBYBYTHETHETHETHE CURVATURECURVATURECURVATURECURVATUREOFOFOFOF

COMPOSITECOMPOSITECOMPOSITECOMPOSITE CYLINDERCYLINDERCYLINDERCYLINDER

Hui-mingWANG1, Yong-kang WEI2, Long ZHOU3*

Department of Engineering Mechanics, Zhejiang University, Hangzhou 310027


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveIn recent years, enhancing the magnetoelectric (ME) effect research in multiferroic material/composite has attracted broad attentions. As single-phasemultiferroic materials exhibit only very weak ME effect, research is now switched to the corresponding composites. There are some methods toincrease the ME effect including the investigation of single-phase materials for the largest possible polarization or magnetization, and the interfacedesign for possible large magnetism. It was recently showed that the ME effect could be enhanced if one can properly grade the material property of thecomposite, or by varying the mechanical boundary conditions. In the ME effect studies discussed above, the multiferroic composites were assumed tobe in a horizontally layered plate shape. While some experimental analyses were carried out using composite cylinders with some interestingobservations, there is no rigorous study on the importance of the curvature. Thus, by deriving an exact-closed form solution for a composite cylinder,this article proves that the ME effect can be tuned and enhanced by the curvature of the cylinder.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsFirstly, we consider a piezoelectric (PE)/piezomagnetic(PM)/ piezoelectric (PE) composite cylinder. The inner layer is piezoelectric, the middle ispiezomagnetic and the outer is piezoelectric. The piezoelectric layer is polarized in the radial direction and is coated with electrodes. And we assumethat the composite cylinder is driven by a time-harmonic uniform radial magnetic field in the PM layer. Secondly, based on the three-dimensionaltheory of magnetoelectroelastic media, the governing equations for PE layer under axisymmetic deformation can be simplified to (under plane-straindeformation). Finally, we carry out the numerical studies after getting the solutions of the boundary value problem. The ME effect for static orlow-frequency case is first investigated. we next consider the ME effect for harmonic driving case in the megahertz(MHz) frequency domain. In thecalculation, the elastic constants of PE and PM layers are multiplied by a complex factor for viscous damping. Such a treatment has two advantages:(1)with the introduced damping, numerical singularity at the resonant frequency can be avoided;(2) it is practical to take account of the energy dissipationin real materials.

ResultsResultsResultsResultsIt should be observed clearly that for the four different sets of mechanical boundary conditions, large ME effect is obtained when the composites aredriven at the resonant frequency, since the resonant frequency can cause a stronger mechanical interaction between PE and PM layers. We also noticethat the mechanical boundary conditions and the radius of the cylinder have significant effect on the resonant frequency and, hence, on the induced MEeffect in the composite cylinder.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsWe can derived an analytical solution for the ME effect in the composite cylinder. The results may show that at a fixed thickness ratio of the layers, thestatic or low-frequency ME effect can be substantially enhanced by increasing the curvature of the cylinder, particularly for the boundary condition caseinvolving traction free.

Keywords:Keywords:Keywords:Keywords: piezoelectric; piezomagnetic; multiferroic material; ME effect; harmonic driving; resonant frequency


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STRUCTURALSTRUCTURALSTRUCTURALSTRUCTURALDYNAMICSDYNAMICSDYNAMICSDYNAMICS DESIGNDESIGNDESIGNDESIGNANDANDANDAND OPTIMIZEOPTIMIZEOPTIMIZEOPTIMIZE OFOFOFOFAXIAL/RADIALAXIAL/RADIALAXIAL/RADIALAXIAL/RADIALCOUPLINGCOUPLINGCOUPLINGCOUPLING

NON-CONTACTNON-CONTACTNON-CONTACTNON-CONTACTPIEZOELETRICPIEZOELETRICPIEZOELETRICPIEZOELETRIC ULTRASONICULTRASONICULTRASONICULTRASONICMOTORMOTORMOTORMOTORWITHWITHWITHWITHAAAA SPHERICALSPHERICALSPHERICALSPHERICALROTORROTORROTORROTOR

Jun-shan WANG1*, Chao CHEN1, Bin JIA1, Xiao-jun YAN2

1 State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics & Astronautics, Nanjing 210016

2 Beijing Aerospace Control Device Institute, Haidian District, Beijing 100039

* Corresponding author, E-mail: [email protected]; Tel.:025-84895945

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUltrasonic motor can be divided into contact type and non-contact type according to driving mechanism at the interface between the stator and rotor.For non-contact type ultrasonic motor, the working mode of non-direct-contact of the stator and the rotor can improve the rotate speed and avoidfriction loss. It is known the acoustics radiation force and the acoustics viscous force generally is the driving force for the non-contact ultrasonic motor.In order to get a high rotate speed, the axial/radial coupling non-contact piezoelectric ultrasonic motor with a spherical rotor was presented in thispaper.An axial suspension and a radial suspension actuator, both of which can form a traveling wave, can provide levitation force and driving force forthe spherical rotor. Unfortunately poor design of constraints and supporting pattern for the suspension actuators have considerate effect on dynamics ofthis type of ultrasonic motor, and low vibration response will be observed in the radial actuator. Thus it cannot provide enough levitation force anddriving force for the spherical rotor. So it’s necessary that the radial suspension actuator is improved to obtain a higher rotate speed of the rotor.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this article, the initial radial stator is analyzed to find out what result in the little vibration amplitude. And some optimization of the structural andconstraint in the radial suspension actuator is made based on the analysis. Then the finite element model of the radial levitation devices built and thedynamics analysis is conducted.The optimized results are compared to the initial one. Then the prototype is manufactured and the suspension actuatormodal parameters are tested. The levitation and driving characteristics of the axial suspension actuator and the radial suspension actuator with aspherical rotor of 40 g are tested respectively through a laser displacement measurement sensor,and compared with characteristics of the wholeaxial/radial coupling ultrasonic motor. After that the coupling effects of the motor are tested to find the levitation and driving characteristics withspherical rotors of different weights.ResultsResultsResultsResultsBy appropriate design and dynamic analysis of the radial suspension actuator, the better vibration response of the prototype was obtained. Moreover itcan be found from levitation and driving characteristics test that the levitation height is not affected much by the radial suspension actuator, but theradial suspension actuator has a very positive effect on the rotate speed of the spherical rotorDiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe appropriate design of supporting pattern and structure parameters, the radial suspension actuator can improve the dynamic characteristics of rotatespeed. However it seems that levitation characteristics won’t be affected too much. Thus the coupling mechanism of NFAL in air gap from bothactuators will be investigated in the future work.

Keywords:Keywords:Keywords:Keywords: levitation; coupling; acoustic radiation pressure; spherical rotorAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: Project Supported by National Natural Science Foundation of China (11174149).



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INFLUENCEINFLUENCEINFLUENCEINFLUENCE OFOFOFOF INITIALINITIALINITIALINITIALSTRESSESSTRESSESSTRESSESSTRESSES ONONONONRESONANCERESONANCERESONANCERESONANCE PROPERTIESPROPERTIESPROPERTIESPROPERTIES OFOFOFOFFBARsFBARsFBARsFBARs

De-jin HUANG*, Xin-yi LUO, Ji WANG

The Faculty of Mechanical Engineering and Mechanics, Ningbo University, Ningbo, Zhejiang 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe piezoelectric thin film bulk acoustic resonators (FBARs) have been used widely as a frequency control device in wireless broadbandcommunication systems nowadays. These devices exhibit several prominent advantages such as small size, high quality factor, high power handlingcapability, high operating frequency, excellent stability against temperature variations and the possibility of being integrated into RFIC (RadioFrequency Integrated Circuits). These kinds of device are usually made of layered structures where thin or thick layers are deposited on an elastic orpiezoelectric substrate. Because of the mismatch of material properties, the layers are most often subjected to high internal residual stress. In themeantime, the layered piezoelectric structure is usually pre-stressed during the manufacture process to avoid brittle fracture. Moreover initial stressesare inevitable in acoustic wave devices due to the complicated manufacturing process with ubiquitous thermal treatment procedures and environmentaltemperature changes. To the author’s knowledge, no studies of initial stress influence on FBAR resonance properties have been reported in theliterature. In this paper, we are concerned with resonance properties of FBARs in thickness-extension mode, where the FBAR is pre-stressed differentmagnitude of initial stress components.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on the fundamental piezoelastic equations of piezoelectric material with initial stresses, the vibration equation of one dimensional ideal FBARunder sine excitation voltage is derived. Free mechanical boundary conditions are applied on the upper and lower surfaces, while sine excitation voltageis applied on these two surfaces for electrical boundary conditions. The solutions of the mechanical displacement and electric potential function withunknown coefficients are obtained by solving these electromechanically coupled field equations. The unknown coefficients can be calculated with theupper and lower surface boundary conditions. The electrical potential is derived from the integral of electrical field, while the current is derived fromthe differential of electrical displacement. Accordingly, the expressions of electrical impedance can be obtained from the electrical potential and current.The series and parallel resonance frequency are then calculated when the electrical impedance tends to infinite and zero. The bandwidth and effectiveelectromechanical coupling factor are calculated from the series and parallel resonance frequency.ResultsResultsResultsResultsThe paper presents the expressions of electrical impedance, series and parallel resonance frequency, bandwidth and effective electromechanicalcoupling factor, which contain the initial stress component. A numerical example is presented to show the influence of initial stress component onelectrical impedance, phase, resonance frequency, bandwidth and effective electromechanical coupling factor.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIt can be found from the procedure of derivation, that among all the initial stress components, only the thickness extension stress component willinfluence the resonance properties. The curves of initial stresses vs. series and parallel resonance frequency, bandwidth and effective electromechanicalcoupling coefficient are plotted. The results show that the initial stress component will improve the resonant frequency and bandwidth. Theapproximately linear relations can be found between frequency, bandwidth and initial stress component. The initial stress component has no influenceon the electromechanical coupling factor. The equations, solutions, and method will be important for the improvement of designing FBARs.

Keywords:Keywords:Keywords:Keywords: FBAR; Initial stress; Resonance frequency; Bandwidth;Acknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the State Key Program of National Natural Science of China(10932004), the Key Team ofTechnological Innovation of Zhejiang Province (2011R09025-02), the Natural Science Foundation of Zhejiang Province (LY12F01015), the KeyScientific Research Fund of the Department of Education of Zhejiang Province (Z201018143) and the Natural Science Foundation of Ningbo（2011A610183）.



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STUDYSTUDYSTUDYSTUDY ONONONON THETHETHETHE FIBERFIBERFIBERFIBER SENSORSENSORSENSORSENSOR PGCPGCPGCPGCMODULATIONMODULATIONMODULATIONMODULATION BASEDBASEDBASEDBASEDONONONON PZTPZTPZTPZT

De-sheng CHEN*, Xiao-di HUANG, Hai-bin WANG, Lei JIANGInstitute of Acoustics, Chinese Academy of Sciences, Beijing 100190

* Corresponding author, E-mail: [email protected] Tel.: 010-82547830

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePhase generated carrier (PGC) modulation-demodulation technique is the main demodulation technique for fiber sensors, which are widely used inacoustic detection, geographic expedition and medical examination. There are two methods to realize PGC modulation. One method is direct lasersource modulation, the other is to modulate PZT in a fiber optic interferometer. The former is called PGC inner modulation, and the later is called PGCexternal modulation. Because the PGC inner modulation needs modulatable laser source, it costs much more than PGC external modulation. However,there is less study on the PGC external modulation than PGC inner modulation. In this paper, we focus on the PGC external modulation to analyze itscharacteristic.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAn experimental system based on PGC external modulation is established. A double-beam fiber optic interferometer is connected with a fiber sensor.The PZT phase modulator is placed in one arm of a double-beam fiber optic interferometer. When PZT is modulated by a single frequency signal, thedeformation of PZT causes the change of fiber length. So the phase difference of the two arms of the fiber optic interferometer is modulated. In thisway, the PGC external modulation is realized, and the signal of the fiber sensor can be demodulated by PGC demodulation technique. What's more, anexperimental system based on PGC inner modulation is established. The self noise of PGC inner modulation and PGC external modulation is measuredto compare their performances.ResultsResultsResultsResultsThe self-noise of PGC external demodulation is 45dB at 1000Hz, which is no greater than that of PGC inner demodulation.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe Experiment results indicate that the PGC external modulation based on PZT can be more widely used in fiber sensors because of its low cost andlow self-noise.

Keywords:Keywords:Keywords:Keywords: PZT; PGC; external modulation; demodulation; fiber sensorAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11074272).


AbstractAbstractAbstractAbstract bookbookbookbook ofofofof TheTheTheThe 2011201120112011 SymposiumSymposiumSymposiumSymposium onononon Piezoelectricity,Piezoelectricity,Piezoelectricity,Piezoelectricity,AcousticAcousticAcousticAcoustic Waves,Waves,Waves,Waves, andandandand DeviceDeviceDeviceDevice ApplicationsApplicationsApplicationsApplications Nov. 23-25, 2012

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RESEARCHRESEARCHRESEARCHRESEARCHONONONONDRIVIDRIVIDRIVIDRIVINNNNGGGGTECHNOLOGYTECHNOLOGYTECHNOLOGYTECHNOLOGYFORFORFORFORAAAA FOUR-PHASEFOUR-PHASEFOUR-PHASEFOUR-PHASE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC LINEARLINEARLINEARLINEAR

MOTORMOTORMOTORMOTOR

Guan-yin YU*, Song PAN, Wei-hua LIU, Yin WANGState Key Laboratory of Mechanics and Control of Mechanical Structures,

Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China

* Corresponding author, E-mail:[email protected]; Tel.:15905172936

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric ceramic has advantages such as: small displacement high resolution, high frequency response, no heat, no noise etc., therefore it becomesan ideal micro-displacement actuator component, which has been widely used in precision positioning, micro electronic mechanical systems (MEMS),and nano-technology. In order to increase the displacement and force of the piezoelectric ceramic actuators, the piezoelectric ceramic stacks are usuallyused, which let the piezoelectric ceramic actuator present high reactive impendence and make it difficult to design the corresponding driving powers.The design of a new driver applied to piezoelectric linear motors is proposed.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsTo reduce the scale of system a embed controller had been used to replace the traditional computer system which takes weaker noise, smaller scale andpower consume. The integrate control system funded gives the foundation of portable micro system based on piezoelectric stack, melting the designeddriver and controller. According to the requirements of piezoelectric linear motor, a signal generator providing 4-phase sin wave voltage signal with 90° phase difference is designed. The embedded chip is used as the main processor, and the DMA data transmission technique is adopted to increase theefficiency of the main processor. Based on the error-amplified principle, a linear power amplifier circuit that enlarges the range of the voltage output ofthe dynamic power supply through using a high-voltage linear amplifier is designed. In order to achieve the linear control of high-voltage output inoperational amplifier, based on the electrical properties of power MOSFET, a high-voltage which adopts half-bridge inverter topology is designed. Theprinciple of the driving power proposed is verified through the simulation results in Multisim10, which also is used to determine the parameters of theelectric circuit and predict the performance of the driving power. The output voltage is 200 V can be acquired. The laser interferometer is used tomeasure the micro displacement of piezoelectric ceramics under 4-phase sin wave voltage excitation with 90°phase difference.ResultsResultsResultsResultsThe 90°phase difference of the 4-phase sin wave voltage signal possesses long-time stability, with the linearity better than 99%. With a piezoelectricceramic load (equivalent capacitance of 500nF), the amplifier characteristics and amplifier performance are analyzed to provide a maximum outputvoltage of 150V, a large-signal bandwidth greater than 1kH, a charge/discharge current of order 250mA. Through the amplitude-frequency anddisplacement-frequency curve, the displacement and its influence factors of the piezoelectric ceramics are discussed initially. The piezoelectric linearmotor operates well under the alternation excitation of the driving 4-phase sin wave voltage signal. By applying the output voltage signal topiezoelectric stacked in a piezoelectric linear motor, the stator of the motor is able to push its mover move with pace length of 1 micrometer.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe experimental and analytical results demonstrate that long-time stability, wide bandwidth and high voltage can be achieved with power MOSFETSand a closed-loop circuit. With the alternation excitation of the stator, the displacement of the piezoelectric linear motor is increased. The driver can bebetter used in piezoelectric linear motors, which indicates the high linearity, and with low cost, it is suitable for application in piezoelectric linearmotors. Therefore there is significance in this driving technology of the capacitive load.

Keywords:Keywords:Keywords:Keywords: piezoelectric linear motor; DMA; linear amplifier; piezoelectric stacksAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the NFSC Guangdong Joint Fund (U0934004).


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DESIGNDESIGNDESIGNDESIGNANDANDANDANDANALYSISANALYSISANALYSISANALYSIS OFOFOFOFAAAA LONGITUDINALLONGITUDINALLONGITUDINALLONGITUDINALPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC VIBRATIONVIBRATIONVIBRATIONVIBRATION EXCITEREXCITEREXCITEREXCITER

Zhi-qiang LI1,2*, Xi-ping MO1, Yong-ping LIU1, Yao-zong PAN1

1 Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190

2 University of Chinese Academy of Sciences, Beijing 100190


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe vibration exciter is widely used in endurance test, tension test and calibration of vibrating transducers by exerting the required sinusoidal force ordisplacement on mechanical equipments. Vibrating machines also need exciters to achieve the function of conveying, screening, compacting andtamping. According to the driving type， the vibration exciters can be classified into inertial exciter, dynamic exciter, electromagnetic exciter,electrohydraulic exciter, gas-operated exciter and piezoelectric exciter. Mostly, the piezoelectric exciters are used in thin-walled structure’s vibration.Application of this kind of exciter is limited because of the low power, narrow bandwidth, high frequency, and associated mass. Improving the power,widening the work bandwidth and reducing the harmonic frequency are the main development trends of piezoelectric vibration exciters. Longitudinalpiezoelectric vibration exciter can excite strong forces at frequencies near the harmonic frequency. The harmonic frequency and bandwidth of excitedforces can be changed by altering the structure of the exciter, and forces can be increased by raising the applied voltage. The longitudinal piezoelectricvibration exciter is expected to produce forces that are more than 10N from 100Hz to 2 kHz.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe paper is about the design and analysis of the longitudinal piezoelectric vibration exciter. Finite element method is applied to simulate the stressdistribution, and the result data are processed by MATLAB. The piezoelectric vibration exciter is mainly composed of three parts---the back plate madeof brass, the driving element made of piezoelectric ceramics, and the business end made of hard aluminum. The back plate should be heavy while thebusiness end should be light so that the stress and displacement are concentrated on the business end. Forces are obtained by calculating the integral ofaveraging stresses on the front surface, which is expected to be more than 10N from 100Hz to 2kHz. The business end is clamped at first to simplify theanalytical model. After the structure being initially settled, different mechanical impedances are applied on the surface of business end to test the effectand make further improvements.ResultsResultsResultsResultsThe frequency-force spectra show that sharp peaks are available at harmonic frequencies (near 1.5kHz); With the decreasing of frequency, forcesdecrease fast and close to zero, while with the increasing of frequency, forces decrease a little slower and close to a nonzero value. The larger appliedmechanical impedances lead to higher harmonic frequencies and forces. Forces at 100Hz to 1 kHz have very small values when the applied voltage is1V, but we can meet the requirement by improving the voltage without exceeding the limited voltage of piezoelectric ceramics.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results reveal that the designed longitudinal piezoelectric vibration exciter fulfills the requirements. Especially, forces at 1.2 kHz to 2 kHz can beeasily achieved at a low exciting voltage.

Keywords:Keywords:Keywords:Keywords: piezoelectric vibration exciter; longitudinal stress; exciting forceAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10372945).


http://www.jukuu.com/show-vibrating-0.html

http://www.jukuu.com/show-machine-0.html


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DOADOADOADOAESTIMATIONESTIMATIONESTIMATIONESTIMATIONOFOFOFOFTHETHETHETHEMOVINGMOVINGMOVINGMOVINGTARGETSTARGETSTARGETSTARGETS ININININ SHALLOWSHALLOWSHALLOWSHALLOWWATERWATERWATERWATER BASEDBASEDBASEDBASEDONONONON

NORMAL-MODENORMAL-MODENORMAL-MODENORMAL-MODETHEORYTHEORYTHEORYTHEORYANDANDANDANDVECTORVECTORVECTORVECTOROPTIMIZATIONOPTIMIZATIONOPTIMIZATIONOPTIMIZATION BEAMFORMINGBEAMFORMINGBEAMFORMINGBEAMFORMING

Nan-song LI1*, Sheng-chun PIAO1, Hai-yan SONG2

1 Science and Technology on Underwater Acoustic Laboratory, Harbin Engineering University, Harbin 150001

2School of Electrical and Information Engineering, Heilongjiang Institute of Technology, Harbin, Heilongjiang 150050


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe performance of the DOA Estimation is one of the most important indexes for sonar system. But in practical engineering, due to ignoring theinfluences of the underwater acoustic channel and the array position errors and some other factors, the resolution and the noise interference suppressionability of the conventional high-resolution methods both become poor. In order to solve the above problems, the Vector Optimization RobustBeamforming method is studied in this paper, which improves the robustness through imposing a strong joint constraint on the weight vector norm andthe steering vector errors. In addition, comparing with the matched-field processing method, the azimuth of underwater Moving Targets can beestimated by combining Adaptive Robust Beamforming and Normal-mode theory. Simulation analysis and experiment results show that this algorithmcan significantly improve the robustness of adaptive beamforming and has better noise interference suppression ability.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThis paper mostly contains: Firstly, Normal-mode theory is used to constitute the model of underwater Moving Targets, whose mode is simulated bysoftware of Kraken.Secondly, a new DOA estimation method named‘Vector Optimization Beamforming’ is proposed. The method improves Standard CaponBeamforming(SCB) through imposing a strong joint constraint on the weight vector norm and the steering vector errors.Thirdly, the robust DOA estimation method for the moving targets is proposed in the application to the remote detecting sonar system in the shallowwater. We establish the array signal model according to the Normal-mode theory and apply a vector optimization method to impose constraintconditions on the actual source vectors in order to improve the robustness for the high-resolution bearing estimation with the uncertainty of waterthermocline depth、water depth, sound velocity gradient and other factors in shallow water.Finally, the robust DOA estimation method for the moving targets in the shallow water is converted into the problem of the second order cone program(SOCP) by the regularization method and is solved by the mathematic tool, SEDUMI. On this basis, the approximate analytic formula for theoptimization weight vector calculation is obtained according to the fast Lagrange algorithm, and then the influence of each normal mode to thegeneralized Diagonal loading is analyzed.ResultsResultsResultsResultsThe simulation and experimental results show that the proposed algorithm has higher spectral peaks and lower sidelobe level under the conditions ofdifferent SNRs, incidence angles, water thermocline depth、water depth and sound velocity gradient uncertainties. At the same time, it keeps bettersuccess probability and bearing estimation accuracy. So the algorithm based on Normal-mode theory has better DOA estimation resolution and noiseinterference suppression ability.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn this paper, the underwater acoustic channel model and the excellent robust adaptive beamforming technique are combined to propose the highlyrobust bearing estimation method for moving targets in shallow water. It is shown that the algorithm performance can be improved significantly whenthe model parameters are uncertainty and mismatched.There are two points which can be further studied: one is the broadband signal processing based on normal mode in shallow water and the other is thatthe real-time algorithm should be improved.

Keywords:Keywords:Keywords:Keywords: normal mode; underwater acoustic signal; vector optimization; moving targetsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11104044); The work was supportedby the Fundamental Research Funds for the Central Universities (No. HEUCFZ1211);The work was supported by the Science and TechnologyFoundation of State Key Laboratory (No. 9140C200103110C20).



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THETHETHETHEMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRIC EFFECTSEFFECTSEFFECTSEFFECTS OFOFOFOFTERFENOL-D/PZT/TERFENOL-DTERFENOL-D/PZT/TERFENOL-DTERFENOL-D/PZT/TERFENOL-DTERFENOL-D/PZT/TERFENOL-D LAMINATEDLAMINATEDLAMINATEDLAMINATED


Long XIA, Jian-ke DU*, Ting-feng MA, Ji WANGSchool of Mechanical Engineering and Mechanics, Ningbo University,

818 Fenghua Road, Ningbo, Zhejiang 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveMagnetoelectric (ME) laminated materials combining magnetostrictive and piezoelectric layers exhibit excellent magnetoelectric coupling effects, andmeet the demands of practical application for sensors, transducers etc. In laminated ME composites, elastic deformation is produced by an externalmagnetic field applied to the magnetostrictive layers by means of magnetostrictive effects, and the strain is then transmitted to the piezoelectric layers,resulting in an induced charge output from the piezoelectric effects. We here focus on the magnetoelectric effects of laminated ME structures ofTerfenol-D/PZT/Terfenol-D by means of experiments.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe testing platform of magnetoelectric effects are designed and built, through which we can test the magnetoelectric effect of theTerfenol-D/PZT/Terfenol-D specimen. The magnetoelectric specimen consists of two Terfenol-D layers and a PZT layer. Terfenol-D layers aremagnetized in their longitudinal direction, while the PZT layer is polarized in its thickness direction. Both Terfenol-D layers and the PZT layer vibratealong the longitudinal direction. The magnetoelectric material specimen is located in the gap of two magnets which can produce changing magneticfield.ResultsResultsResultsResultsAccording to the experiment results we can find ME coupling coefficient is much higher when working at resonance station. The resonance frequencyof the ME specimen decreases with the increasing basic magnetic field, reaches a minimum and then increases. The increasing basic magnetic field alsomakes ME coefficient increasing rapidly then down a little. The bias magnetic field can reduce the current loss of specimen. We further test the effectof a tiny bias magnetic field to the resonant frequency and ME coefficient, and test the sensitivity of ME specimen. Through the above experimentsanalysis, the optimal bias magnetic field can be determined around 350Oe.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsMagnetoelectric voltage transformation coefficient is one of the important indexes of measuring the performances of magnetoelectric laminatedmaterials. Therefore, the emphasis of our experiment is to measure the output voltage of magnetoelectric laminated materials in different conditions,then to obtain the magnetoelectric voltage transform coefficient. The influencing factors upon magnetoelectric voltage transformation coefficientmainly focus on the bias magnetic field and frequency of alternating magnetic field. It is shown that magnetoelectric voltage transformation coefficientwhen working in resonant frequency is much higher than in common condition. When the bias magnetic field of is 400Oe, the frequency of alternatingmagnetic field is from 10Hz to 2kHz, and the alternating magnetic field is about 1Oe, the magnetoelectric voltage transformation coefficient of thetesting platform can be determined about 9.6V/(cm.Oe); when the frequency of alternating magnetic field is from 30kHz to 100kHz, the highestmagnetoelectric voltage transformation coefficient can be up to 584.8V/(cm.Oe) (working around the resonant frequency).

KeywordsKeywordsKeywordsKeywords: terfenol-D; magnetoelectric; piezoelectric; vibrationAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements: The work was supported by the National Natural Science Foundation of China (Nos. 11072116 and 10932004), ZhejiangProvincial Science Fund for Distinguished Young Scholars (No.LR12A02001), K.C.Wong Education Foundation, Hong Kong and K.C.Wong MagnaFund in Ningbo University.



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RESEARCHRESEARCHRESEARCHRESEARCHOFOFOFOFTHETHETHETHE S-TYPES-TYPES-TYPES-TYPE LINEARLINEARLINEARLINEAR PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICMOTORMOTORMOTORMOTOR

Sheng ZHANG1*, Yin WANG2, Wei-qing HUANG 3

1 State Key Laboratory of Mechanics and Control of Mechanical Structures,



Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePeristalsis type precision drivers adopt the laminated piezoelectric ceramics as actuator element, they have the characteristics of low voltage driver,direct output the large deformation, and avoid the strongly nonlinear output performance caused by the resonance, However, a problem in the motordevelopment is the larger spacing between the clamp feet, Which requires higher processing accuracy of the promoter and makes the structure ofsystem complicated, In addition, the piezoelectric motor based on the principle of the inchworm adjusts the clamping force by adjusting thepre-tightening force or spacing between the stator and the promoter , and therefore they don’t have the self-locking ability. In this paper, we propose anS-type linear piezoelectric motor, as a classification of the piezoelectric stepper precision drive, which not only has the above advantages, but also dueto the use of the spring preload agencies, the motor has self-locking function, which reduces the machining accuracy, the cost of the motor, and providea larger driving force.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe structure of S-type linear piezoelectric motor includes a stator component and promoter component, the stator assembly consists of a combinationof S-shaped displacement conversion mechanism, the laminated piezoelectric stack and support structure. The combination of S-shaped displacementconversion mechanism consists of three displacement conversion mechanism layers end to end. The upper and lower levels of displacement conversionmechanism preload a set of laminated piezoelectric stack and play the role of enlarging the laminated piezoelectric stack deformation and clamping.The middle layer of conversion mechanism preload two sets of laminated piezoelectric stack and placed a support component between the two sets oflaminated piezoelectric stack to fix the stator assembly. There are two contact surfaces between promoter components and stator components, one sidecan translate along the vertical direction of the surface, this surface is fixed through parallel institutions, the parallel use of the flexible hinge theiractivities connect the spring preload institutions, which impose a pre-pressure between the stator and the promoter, to achieve self-locking feature.ResultsResultsResultsResultsThe structure and working principle of a inchworm-type piezoelectric linear actuator are analyzed, and the mechanical system dynamic modal of theactuator is established. Based on the analysis of the actuator's stator, the output performance of proposed actuator is analyzed, experimental resultsshow that the output displacement of the actuator is stable, and the displacement for single step is 3μm when the actuating voltage is 100 V. Thevelocity and acceleration properties of the linear actuator are tested. According to the testing results, the dynamic response performance of the actuatoris analyzed deeply. The experimental results show that the proposed piezoelectric linear actuator has good dynamic performance and motion stability.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe displacement for single step is 3μm when the actuating voltage is 100 V and the proposed piezoelectric linear actuator has good dynamicperformance and motion stability.

Keywords:Keywords:Keywords:Keywords: piezoelectric linear motor; inchworm motion; piezoelectric stack; the ground-clampAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the NFSC Guangdong Joint Fund (U0934004).


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STUDYSTUDYSTUDYSTUDYONONONONDESIGNDESIGNDESIGNDESIGNANDANDANDAND EXPERIMENTALEXPERIMENTALEXPERIMENTALEXPERIMENTALOFOFOFOFAAAA PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC LINEARLINEARLINEARLINEARMOTORMOTORMOTORMOTORUSINGUSINGUSINGUSING

DOUBLEDOUBLEDOUBLEDOUBLE DRIVINGDRIVINGDRIVINGDRIVING FEETFEETFEETFEET

Wei-hua LIU1*, Guan-yin YU2, Yu LIANG3, Wei-qing HUANG4

State Key Laboratory of Mechanics and Control of Mechanical Structures,


* Corresponding author, E-mail:[email protected]; Tel.:15895976022

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveWith the rapid development of modern precision manufacturing industry，actuators with high resolution and long stroke are needed in many applicationfields. Because of the unique advantages such as self-locking on the power off, compact structure, fast response etc., piezoelectric actuators have beentaking place of the traditional actuators which are based on the principle of electromagnetic induction. Piezoelectric resonant linear motor works inresonance, so the frequency is restricted. But this research is based on non-resonant and the frequency band is wide. The piezoelectric stacks work asexciting components. One piezoelectric stack is comosed of multilayer piezoelectric ceramics which forms a structure mechanically in series andelectrically in parallel to overcome small output strain of the piezoelectric ceramic. It is capable of large displacement output under low voltage. Themotor can work in a very low frequency. The double feet drive the mover alternately. It improves the efficiency of the motor and makes motor runcontinuously.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsTwo stators are adopted and each of them has four pieces of piezoelectric stacks. Two pieces of piezoelectric stacks are placed together. They aresymmetrical in space and space different 90。. Driven by four sine wave signals with the same frequency and phase difference of 90。.Each of the statorforms an elliptical trajectory at the driving foot. When there is one stator, it works only half of the period. But two stators solved this problem. Thedouble feet drive the mover alternately. That is to say, when the rotor and one of the driving feet are in separated state, the driving foot stays at thedeclining semicircle of the elliptical trajectory, but the other driving foot just right at the rising semicircle of the elliptical trajectory. So the motor candrive the mover continuously.ResultsResultsResultsResultsDesign requirements of this motor were presented first and the structure of the motor was proposed. By modeling its stator, the operating principle ofthe motor was analyzed. In order to validate the feasibility of the principle, a prototype was made. The experimental results of the prototype show that itoperated on non - resonant vibration and used double driving feet. Driven by four sine wave signals with the same frequency and phase difference of90

, the two driving feet moved along the elliptical trajectory alternately and pushed the slider running linearly. When proper preload is applied

between the stator and rotor, the maximum no-load velocity of the motor is 2mm/s, and the maximum thrust force of the motor is 4N.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsA double driving piezoelectric actuator using piezoelectric stacks is designed and fabricated. The operating principle of actuator is presented and thestructure is designed. The actuator has the characteristics of simple in structure and convenient in assembly, and has more advantages in its smallvolume. The structure can be better used in micro-electromechanical system, and with its small volume it is suitable for application in small preciseinstruments, therefore the motor has a good application prospect.

Keywords:Keywords:Keywords:Keywords: piezoelectric linear motor; double driving feet; non-resonant vibration; stator driving footAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by NFSC Guangdong Joint Fund (U0934004) and NUAA Research Funding No. NJ20120001.


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SIMULATIONSIMULATIONSIMULATIONSIMULATIONOFOFOFOFSEISMICSEISMICSEISMICSEISMICWAVEWAVEWAVEWAVE PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININ SHALLOWSHALLOWSHALLOWSHALLOWWATERWATERWATERWATER ENVIRONMENTSENVIRONMENTSENVIRONMENTSENVIRONMENTS

Li LI*, Sheng-chun PIAO, Hai-gang ZHANG, Ya-xiao MOScience and Technology on Underwater Acoustic Laboratory, Harbin Engineering University, Harbin 150001

*Corresponding author, E-mail: [email protected]; Tel.:15124509861

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAn important topic in underwater acoustics is wave propagation simulations in range dependent, shallow water environments. When the acoustic waveis incident at the ocean bottom surface, energy is coupled into the bottom as seismic motion. And sea-floor seismic wave will be generated byunderwater sources if the bottom is elastic. More and more interest and efforts are shifting to simulations of seismic wave propagation in elastic oceanbottom in recent years. To obtain an accurate solution and to meet with the realistic situations, people must take complex environments into account.While many numerical techniques are developed and consummated to solve 2D models, the objectives of ocean acoustics are now focus on handlingsimulations of wave propagation in the time domain for 3D configurations. The purpose of this article is to find a suitable method in the context ofseismic wave propagation induced by sources in water, and both Fourier synthesis method and the spectral element method (SEM) are well introduced.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAs underwater sources are now at low frequency, most of seismic processing methods can be adapted or directly used to underwater acoustic problemsin shallow water with elastic bottom. One part of this work is to study the propagation of broadband sound pulses in shallow water environments. Thenumerical method used to solve the time-dependence acoustic problems is based on Fourier synthesis of frequency-domain solutions. For the other partof this work, more complex geometries and interface conditions are taken into consideration, so the spectral element method becomes the particularchoice for performing wave propagation simulations in underwater acoustics in the time domain. This method combines the generality of the finiteelement method with the accuracy of spectral techniques. Although the computing power has increased considerably, the amount of computation inunderwater acoustics is really great, especially of complex wave propagation. So parallel programming is tried to improve the computational efficiency.ResultsResultsResultsResultsBroadband pulse propagation in shallow water with elastic bottom is simulated with normal mode, fast field, and parabolic equation modelcomputations. Both Fourier synthesis and spectral element method for seismic wave propagation simulations are presented for several underwateracoustic examples. The sound field radiated by a water-bomb source and propagating in shallow water is strongly affected by the acoustic parameters ofthe ocean bottom, especially speeds of the compressional wave and the shear wave. The parameters’ effects on the distribution of normal modes andsurface waves are also analyzed, and the time series modeling agrees with the analysis very well. Transmission losses are computed respectively byinversion of time domain solutions and frequency-domain models, such as parabolic equation model. The comparison of transmission losses shows thatthe SEM is an excellent numerical approach to the simulation of seismic wave propagation.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe frequency domain method, Fourier synthesis, is used to simulate the wave propagation in shallow water, and the frequency-domain solutions areobtained from existent propagation models. The time domain method, SEM is applied to modeling the propagation of acoustic waves in the ocean incomplex configurations and in different types of media. And the transmission losses curves are drawn by processing the received signals through fastFourier transform. Then the validation of the SEM for shallow water propagation simulations is presented. With suitable meshing software, morecomplex models can be simulated by the SEM. And 3D simulations will be made possible as parallel computing develops in the near future, which cansave running time effectively.

Keywords:Keywords:Keywords:Keywords: seismic wave propagation; spectral element method; time domain solutions; Fourier synthesisAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11104044).



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PIEZOMAGNETICPIEZOMAGNETICPIEZOMAGNETICPIEZOMAGNETIC LOVELOVELOVELOVEWAVESWAVESWAVESWAVES ONONONONORTHORTROPICORTHORTROPICORTHORTROPICORTHORTROPIC PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC HALF-SPACESHALF-SPACESHALF-SPACESHALF-SPACES

Yan-ping KONG 1,2*, Ruo-meng TIAN2, Jin-xi LIU2

1 Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044

2Department of Engineering Mechanics, Shijiazhuang Tiedao University, Shijiazhuang 050043*Corresponding author, E-mail: [email protected]; Tel.: 0311-87935529

Layered structures play an important role in MEMS(microelectromechanical systems).This paper investigates Love waves propagating in the layeredplate structure consisting of a piezomagnetic layer and a orthotropic piezoelectric half space. The Love waves can propagate in the resulting structureand the dispersion relations of the Love waves are obtained. In the case of a Terfenol-D layer over a KbNO3 substrate, the wave exists at any rotatedcuts. The results showed the speed of the first mode starts at the B-G wave speed at wave number equal to zero and decrease toward the velocity ofshear body waves. The graphs display the phase velocity dependence of the cutting angle and the speed of these waves is sensitive to the rotated cuttingangle.

Keywords:Keywords:Keywords:Keywords: piezomagnetic material; orthotropic; piezoelectric material; love wave; dispersionAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10912147).



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RAYLEIGHRAYLEIGHRAYLEIGHRAYLEIGHWAVESWAVESWAVESWAVES ININININAAAA PIEZOMAGNETIC/PIEZOELECTRICPIEZOMAGNETIC/PIEZOELECTRICPIEZOMAGNETIC/PIEZOELECTRICPIEZOMAGNETIC/PIEZOELECTRIC STRUCTURESTRUCTURESTRUCTURESTRUCTURE

Qing-guo XIA, Jian-ke DU*, Ji WANGSchool of Mechanical Engineering and Mechanics, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSurface acoustic wave (SAW) devices are widely used in the fields of electric engineering, mechanical engineering, and communications, etc. The thinfilm material structures are more suitable for manufacturing the SAW devices or bulk acoustic wave (BAW) devices because higher frequency can beacquired. The development of micro-acoustic sensors in biosensing and chemical sensing fields provide the need for further investigations of theRayleigh wave propagation in layered magneto-electro-elastic structure, where a piezoelectric substrate is covered with a thin piezomagnetic layer. Inpractice, it is of importance to analyze the effects of biasing fields such as magnetic field and electric field, etc. on the Rayleigh wave propagation forthe design of acoustic resonators, sensors, and actuators.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe investigate the propagation of Rayleigh-type surface acoustic waves in a layered piezomagnetic/piezoelectric structure under a biasing magneticfield. The governing equations of the Rayleigh waves can be obtained on the basis of the linearly magneto-electro-elastic theory. The displacements,electric potential, magnetic potential, stresses, electric displacement, and magnetic induction are continuous across the interface of the thin layer and thesubstrate together with the traction free and the magneto-electrically open and short conditions on the surface of the structure. The phase velocity inbiasing magnetic fields can be obtained by solving the dispersive relation using Matlab software. The relationships between phase velocity andnon-dimensional wave number with consideration of biasing magnetic fields are figured and discussed.ResultsResultsResultsResultsThe analytical solution of dispersion relations are obtained for mechanical and magneto-electrical boundary conditions. The phase velocity is calculatedand figured. The distributions of the displacements, electrical potential and magnetic potential are also investigated and presented. The effects of thebiasing field and piezomagnetic coefficient on the properties of the Rayleigh waves are discussed in detail. We can find that the biasing magnetic fieldshave great effects on the properties of Rayleigh waves.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results show that the phase velocity decreases with the non-dimensional wave number. We can obtain similar results for different boundaryconditions. In addition, the effects of piezomagnetic coefficient and magnetic conductivity on disperse characteristics are analyzed, respectively. Theresults also show that the phase velocity decreases with the piezomagnetic coefficient. The effects of the magnetic conductivity on dispersecharacteristics are not remarkable. It can be seen that the phase velocity is sensitive to the biasing magnetic field, the boundary conditions and thepiezomagnetic coefficient. These analytical method and the results are useful for the design of the magnetoelectric resonators and sensors.

Keywords:Keywords:Keywords:Keywords: rayleigh waves; piezoelectric; piezomagnetic; biasing magnetic fieldAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Nos. 11072116 and 10932004), ZhejiangProvincial Science Fund for Distinguished Young Scholars (No.LR12A02001), K.C.Wong Education Foundation, Hong Kong and K.C.Wong MagnaFund in Ningbo University.



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BANDBANDBANDBANDGAPSGAPSGAPSGAPS CALCULATIONCALCULATIONCALCULATIONCALCULATIONOFOFOFOFSCALARSCALARSCALARSCALARWAVESWAVESWAVESWAVES ININININ TWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALPHONONICPHONONICPHONONICPHONONIC

CRYSTALSCRYSTALSCRYSTALSCRYSTALSWITHWITHWITHWITHGENERALIZEDGENERALIZEDGENERALIZEDGENERALIZEDMULTIPOLEMULTIPOLEMULTIPOLEMULTIPOLETECHNIQUETECHNIQUETECHNIQUETECHNIQUE (GMT)(GMT)(GMT)(GMT)

Zhi-jie SHI1*, Yue-sheng WANG1, Chuan-zeng ZHANG2

1Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044, China2Department of Civil Engineering, University of Siegen, D-57068 Siegen, Germany

*Corresponding author, E-mail: [email protected] ; Tel.: 010-51468750

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThere has been a steady growth of interest in the propagation of the elastic/acoustic waves in phononic crystals both experimentally and theoretically inthe last decades. One primary problem for these investigations is to compute the band structures (dispersion curves) and search for so-called completephononic band gaps. In order to obtain the band structures, several numerical methods have been proposed. But it is well known that each of thesemethods has its own disadvantages. In this paper, an efficient novel method is proposed for band structure calculation for scalar waves intwo-dimensional phononic crystals based on generalized multipole technique (GMT).StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this method, the fields are expanded using the fundamental solutions with multiple origins. This makes it possible to deal with the phononic crystalswith non-circular inclusions. An additional excitation source is introduced, thus the original eigenvalue problem is transformed into a response problem.The minimum points of the responded curve imply the required eigenvalues. To get the smooth responded curve, two regularizing procedures areintroduced. By sweeping the frequency range of interest and sweeping the boundary of the irreducible first Brillouin zone (IFBZ), the band structurewill be obtained.ResultsResultsResultsResultsIn this paper phononic crystals with different lattices and different shaped inclusions are considered. In comparison with the finite element method(FEM), it is found that this method can be used to calculate band structure at a very high accuracy and a reasonable computational cost.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe method proposed in this paper has a high degree of validity, accuracy and flexibility, and is not limited to 2D case, and is easily extendable forapplications involving localized defect modes analysis, various phononic crystals defect waveguide types and visco-elastic phononic crystals, as well.One important feature of this method is that it can yield band structures at an arbitrary frequency range which does not necessarily start from zero.

Keywords:Keywords:Keywords:Keywords: phononic crystals; generalized multipole technique (GMT); band gaps; eigenvalue problemsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The authors are grateful to the National Natural Science Foundation of China (Grant Nos. 51178037 and 10632020), theGerman Research Foundation (DFG, Project Nos. ZH 15/11-1 and ZH 15/16-1) and the International Bureau of the German Federal Ministry ofEducation and Research (BMBF, Project No. CHN 11/045) for the financial support. The second author is also grateful to the support of the NationalBasic Research Program of China (2010CB732104).



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NUMERICALNUMERICALNUMERICALNUMERICALANALYSISANALYSISANALYSISANALYSIS ONONONONTHETHETHETHE SANDWICHSANDWICHSANDWICHSANDWICH DIPOLEDIPOLEDIPOLEDIPOLE LOGGINGLOGGINGLOGGINGLOGGINGTRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCERWITHWITHWITHWITH

VARIOUSVARIOUSVARIOUSVARIOUS LOADSLOADSLOADSLOADS

Qiu-ying CHEN*, Jian-sheng CONG, Xiu-ming WANGState Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAs one of the key parts of acoustic logging instrument, dipole acoustic logging transducer can transfer sound energy into the formation throughacoustically transparent medium (such as silicone oil, mud, etc.) and measure the received signal with stratigraphic information in order to makeformation evaluation. Therefore, study on the effect of fluid load on the logging transducer is significant for the site operations of acoustic logging. Inthis article, it is analyzed how the performance of logging transducer change when excited in fluid loads with different acoustic attributions includingdensity, acoustic velocity and acoustic impedance.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAs the operating mode, the first-order bending vibration of the sandwich dipole logging transducer is numerically analyzed with the finite elementmethod. The impedance characteristics and transmitting voltage response (TVR) level of sandwich dipole logging transducer are numerically calculated.The simulation result is proved by the experimental measurement.ResultsResultsResultsResultsFor the first-order bending vibration of the sandwich logging transducer, the resonant frequency is affected significantly by the density of the load,while it is not sensitive to the acoustic velocity of the load. As the density increases, the resonant frequency decreases. The TVR level of the transduceris affected by both density and acoustic velocity of the load. For the same density, higher acoustic velocity cause lower TVR level, while, for the sameacoustic velocity, higher density cause higher TVR level. In addition, for the two kinds of loads with the same acoustic impedance but different densityand acoustic velocity, the resonant frequency and TVR level are both different from each other.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results above show that the acoustic attributions of fluid loads have effect on the resonant frequency and TVR level of the sandwich acousticlogging transducer. It also shows that the acoustic impedance of fluid loads cannot independently affect the acoustic performance of logging transducer.The analysis results above have certain referent significance for both the simulation design of logging transducer and the site operations of acousticlogging.

Keywords:Keywords:Keywords:Keywords: bending vibration mode; load; resonant frequency; transmitting voltage responseAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the Knowledge Innovation Program of the Chinese Academy of Sciences.



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AAAA STUDYSTUDYSTUDYSTUDYONONONON PERFORMANCEPERFORMANCEPERFORMANCEPERFORMANCEOFOFOFOFSAWSAWSAWSAW DEVICESDEVICESDEVICESDEVICES BASEDBASEDBASEDBASEDONONONONALN/DIAMONDALN/DIAMONDALN/DIAMONDALN/DIAMOND

Hua-lei WANG1, Hui ZHONG1,Yu SHI1, Li-ping LI2, Lin-sheng ZHOU2, Da-guo CAI21State Key Laboratory of Electronic Thin Films and Integrated Devices, University of Electric Science and Technology of China

2Chengdu Liaoyuan Xingguang Electronics Co., Ltd

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSingle-crystal substrates such as LiNbO3, LiTaO3, and quartz are widely used for surface acoustic wave (SAW). Unfortunately, such materials havelow phase velocities, making their operating frequency impractically large above 3 GHz. With the frequency increasing, the pitch of SAW is decreasing,which cause low power duality and high resistance. Diamond substrates, have a SAW phase velocity more than two times higher than those ofsingle-crystal making them suitable for much higher operating frequencies. In this study, we prepare AlN thin film on single-crystal diamond to findhow well the performances of SAW devices are.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAln thin film will be prepared by RF sputtering. Then, we will fabricate one-port SAW resonators using structures of IDT/AlN/ (100) Diamond andIDT/AlN/metal/(100) Diamond. The performance of these resonators will measured and compared. The metal will be Molybdenum, Aluminum andother electrical conductor materials.ResultsResultsResultsResultsPiezoelectric AlN thin films are deposited on Mo/Si by active RF sputter. Al disks with purity of 99.99% as targets and N2 of 99.9% as a gas sourcewere employed for the AlN film deposition. During the deposition, the substrate temperature and deposition rate were kept at 200 and 0.2μm/h,respectively. Fig.1 show the cross section of AlN/mo/Si, the thickness of AlN film is about 1.5μm.

Fig.1 cross section of AlN/Mo/Si

Figure 2 shows the results of XRD analysis for the deposited AlN film. It is seen from Fig. 2 that the c-axis oriented AlN is deposited. From the rockingcurve (see detail in Fig.2), FWHM corresponding to the AlN (002) peak is estimated to be 2.29°. Figures clearly confirm that the RF sputtering methodenables to deposit highly c-axis oriented AlN films on Mo/Si substrates.

30 40 50 60 70 80

0

1000

2000

3000

4000

5000

6000

7000

8000

9000

10000

11000

12000

15 16 17 18 19 20 21 220

2000400060008000

100001200014000

Inte

nsity

(C

PS

)

2 Theta (o)

AlN(002)

AlN(103)

AlN(004)

AlxMoy

Mo(110)

a

Inte

nsity

(CP

S)

Theta (o)

Peak FWHM=2.29o

b

Fig. 2 XRD charts of AlN thin film (thickness = 1.5μm) deposited on Mo/Si substrates


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Fig.3 AFM image of the deposited AlN surface

The surface roughness Ra of the AlN film was estimated to be about 2 nm shown in Fig.3. This suggests that the surface may be smooth enough tofabricate SAW devices consisting of sub-micron Al electrodes.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsResult shows c-axis oriented AlN was deposited successfully on Mo/Si substrate. Next step the AlN film will be prepared on single crystal diamond. Atthe presentation we will show and compare the performance of one port resonator fabricated on the IDT/AlN/Diamond and IDT/AlN/Mo/Diamond.

Keywords:Keywords:Keywords:Keywords: piezoelectric motor, single vibrator, bidirectional rotation, ultrasonic motor


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FABRICATIONFABRICATIONFABRICATIONFABRICATIONOFOFOFOFBULKBULKBULKBULKACOUSTICACOUSTICACOUSTICACOUSTICWAVEWAVEWAVEWAVE RESONATORRESONATORRESONATORRESONATORBASEDBASEDBASEDBASEDONONONONALNALNALNALNTHINTHINTHINTHIN FILMFILMFILMFILM

Jie YANG, Rui ZHANG, Xiang-quan JIAO, Hui ZHONG, Yu SHI*State Key Laboratory of Electronic Thin Films and integrated Devices, University of Electronic Science and technology of China, Chengdu 610054


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveBulk acoustic wave (BAW) resonator based on AlN thin films is compatible with standard IC technologies. This advantage makes sense for realizing aone-chip front-end circuit. AlN thin film is an ideal material for preparing BAW resonator. Preparation of preferred c-axis oriented AlN thin film withno crack in the structure of BAW resonator is the incentive behind this study.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBy optimizing depositing parameters, preferred c-axis AlN film was prepared by an RF reactive sputtering technique. Then a BAW resonator wasfabricated based on AlN thin piezoelectric layer. The CMP process of sacrifice layer and reducing the thickness of bottom electrode were considered toavoid AlN thin film cracked at the stepsResultsResultsResultsResultsThe evolution of preferred orientation and morphology of the AlN films deposited on Mo were studied by X-ray diffraction, field emission scanningelectron microscopy. All results show that the AlN thin film prepared in this work is suitable for the application of BAW resonator. Cross section photoshow that AlN thin film is easy crack at the edge of bottom electrode. By reducing the thickness and extending the edge of bottom electrode, thecracking problem was solved.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsHigh quality c-axis oriented AlN thin film was achieved on Mo electrode. A BAW resonator based on AlN thin film, with 100nm bottom electrode,2500nm AlN piezoelectric layer and 200nm top electrode, was fabricated successfully. The BAW resonator has exhibits a resonant frequency of around1.7GHz.

Keywords:Keywords:Keywords:Keywords: bulk acoustic wave (BAW) resonator; AlN; c-axis oriented; crackAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was supported by National Natural Science Foundation of China (No. 61101038) and Sichuan KeyTechnology R&D Program (No. 2011GZ0220).



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AAAAMETHODMETHODMETHODMETHOD FORFORFORFOR IMPROVINGIMPROVINGIMPROVINGIMPROVINGTHETHETHETHE ELECTRICALELECTRICALELECTRICALELECTRICALLIMITLIMITLIMITLIMITOFOFOFOFLANGEVINLANGEVINLANGEVINLANGEVIN ULTRASONICULTRASONICULTRASONICULTRASONIC

TRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCER

Zhao-feng LIANG1, Xi-ping MO2*, Guang-ping ZHOU1

1Department of Electronic Engineering, Shenzhen Polytechnic, Shenzhen 5180552Institute of Acoustics, Chinese Academy of Sciences, Beijing 100190

*Corresponding author, E-mail: [email protected]; Tel.:0755-26731856

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe demand for high-power ultrasonic transducers is increasing as ultrasonic treatment technology in new areas continues to expand, such as in thechemical and food industry, in sewage sludge plants, et al. Langevin ultrasonic transducer is widely used in high-power ultrasonics because of its highelectro-acoustic efficiency and mechanical strength, as well as easy to optimize. The output power of a Langevin ultrasonic transducer is limited bymany factors, and the electrical limit is one of most important limit factors. The electrical limit of Langevin ultrasonic transducer can be reflectedthrough the voltage-withstand degree of the piezoelectric ceramic wafers used in the transducer. For a common Langevin ultrasonic transducer, allpiezoelectric ceramic wafers have the same thickness and driving voltage, but each wafer’s location in the transducer is different, so theirvoltage-withstand limits are also different. The unequilibrium of voltage-withstand degrees of piezoelectric ceramic wafers hinders the improvement ofLangevin ultrasonic transducer’s electrical limit. In this paper, a method by using piezoelectric ceramic wafers with different thickness in a Langevinultrasonic transducer is presented in order to improve the transducer’s electrical limit.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsSpecifically, under the condition of keeping the overall piezoelectric stack length and the number of the individual ceramics invariable, by increasingthe thickness of the piezoelectric ceramic wafer near the node position and decreasing the thickness of the piezoelectric ceramic wafer far away fromthe node position, the voltage-withstand degrees of all piezoelectric ceramic wafers in the transducer will tend consistent, and accordingly thetransducer’s electrical limit can be improved.ResultsResultsResultsResultsThe FEA software ANSYS is used to analyze the electrical limit of Langevin ultrasonic transducer. A simulation design example shows the validity ofthis optimization method.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsUsing the unequal thickness of piezoelectric ceramic wafers in a Langevin ultrasonic transducer might make the production of wafer slight complex,but it can bring the transducer a longer life and higher electrical limit.

Keywords:Keywords:Keywords:Keywords: langevin ultrasonic transducer; piezoelectric ceramic; electrical limit; ANSYS; optimizationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11174209) and R&D funds ofShenzhen (JC201006020762A).


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AAAADISPERSIVEDISPERSIVEDISPERSIVEDISPERSIVE NONLOCALNONLOCALNONLOCALNONLOCALMODELMODELMODELMODELFORFORFORFOR SHEAR-WAVESHEAR-WAVESHEAR-WAVESHEAR-WAVE PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININ LAMINATEDLAMINATEDLAMINATEDLAMINATED

COMPOSITECOMPOSITECOMPOSITECOMPOSITEWITHWITHWITHWITH PERIODICPERIODICPERIODICPERIODIC STRUCTURESTRUCTURESTRUCTURESTRUCTURE

H. Brito-Santana1*, Yue-sheng WANG1, R. Rodríguez-Ramos21Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044

2Faculty of Mathematics and Computing Sciences, University of Havana, San Lázaro esq. L, Vedado, Havana, CP10400, Cuba

*E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveMany studies in the theory of composite materials are based on the exploitation of the classical continuum model implying that the originalheterogeneous medium can be simulated by a homogeneous one with certain homogenized (so-called effective) mechanical properties. Such anapproach comes naturally from the hypothesis of the perfect rate of microheterogeneity of the composite structure when the microscopic size ofheterogeneities is supposed to be essentially smaller than the macroscopic size of the whole sample of the material so that in the first approximation onemay assume zero. However, this limit is never reached for most practical problems and in real composites the microstructural scale effects may result inspecific non-local phenomena, which cannot be predicted in the frame of the homogenized medium theory.The main objective of this paper is to describe the dispersive behavior of periodic composites by means of time variable asymptotic rescaling, which isa necessary condition for the accurate description of a composite’s global behavior. For this purpose, a reformulation of the problem is made in whichthe slow temporal scale is replaced by a single-frequency time-dependence, and an asymptotic expansion for the main frequencies is assumed to exist.This shows that the time rescaling needed to find the effective law of movement in composites is strongly frequency dependent. As an advantage, thereis no need to study the selection of temporal scales, because the model only treats the fast spatial variable and yields closed form general expressionsfor the coefficients in the global model.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe consider an anisotropic elastic body of periodic structure occupying a bounded region in three- dimensional space with a smooth boundary. Weassume that the region is made up by periodic repetition of the unit cell in the form of a parallelepiped. We also present an analytical solution for theaveraged problem for certain cases.ResultsResultsResultsResultsIn this paper, the problem of shear-wave propagation in laminated composite with periodic structure is studied, and a dispersive asymptotic method forthe description of these dynamic processes is proposed. Assuming a single-frequency dependency of the solution for the two-dimensional waveequation in a periodic composite material, higher-order terms in the asymptotic expansion for the displacement functions are studied. For a selection ofboundary problems, analytic solutions are given and graphically illustrated.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn this work, an asymptotic model for describing wave propagation in periodic composites was proposed. In this approach, the heterogeneous nature ofthe composite introduces a perturbation in the principal frequencies relative to the homogenized problem. As a result, no new temporal scales need beconsidered. Instead, a regular aymptotic expansion for the eigenfrequencies is obtained from the condition of boundedness for the solution. The resultsare graphically illustrated for different types of boundary problems. This approach describes the dispersion effects in periodic composites, and we havediscussed the differences between this model and the classical asymptotic homogenization.

Keywords:Keywords:Keywords:Keywords: composite materials; wave dispersion; asymptotic; homogenization; wave propagation; dynamic asymptotic homogenization.Acknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10632020 and 51178037).


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PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATIONOFOFOFOFNONLINEARNONLINEARNONLINEARNONLINEAR LONGITUDINALLONGITUDINALLONGITUDINALLONGITUDINALWAVESWAVESWAVESWAVES ININININANANANAN ELASTICELASTICELASTICELASTIC RODRODRODROD

Rong-xing WU1,2*, Lan-zhen YU1, Xing-bin ZHU1, Jing YU1, Ji WANG2

1Department of Architectural Engineering, Ningbo Polytechnic, Ningbo 3158002Piezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, Ningbo University, Ningbo 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAcoustic waves propagating in solids have been extensively studied as underline physical principle of many practical methods and techniques forfrequency control and detection applications. Typical examples of such problems include acoustic wave resonators and ultrasonic testing to detect flawsin materials and structure. However, practical applications require such techniques to be extended to consider the propagation of nonlinear waves formore effective evaluation and characterization of material and structural properties and determination of useful ranges. The longitudinal wavepropagation in a nonlinear rod is extremely important because they give us some essential information about nonlinear longitudinal waves and can alsobe used as the preliminary step for the further investigations of nonlinear vibrations of elastic solids with engineering applications in structures andacoustic wave devices.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe nonlinear longitudinal wave propagation in a nonlinear rod is studied by the homotopy analysis method and obtained analytical solutions which arethe same as earlier known results. We also employed the explicit and implicit finite difference methods to solve this nonlinear equation, respectively.ResultsResultsResultsResultsThe analytical solutions we obtained are similar with previous results by other approximate methods and the numerical results showed wave formdepends on many factors such as driving frequency, amplitude, nonlinear elastic constant, and wave velocity. We found that compared with the explicitfinite difference method, the implicit finite difference method need less amount of the grid but require more computational time to obtain reliablesolutions. We also found that the energy of multiple-frequency components becomes larger with longer traveling distance.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results showed that the multiple-frequency components become larger with longer traveling distance which means the energy of the initial singlefrequency component will transfer to the multiple-frequency components. This phenomenon is more obvious for the explicit difference method’s results.It is clear that the nonlinear property of the solid has affected the propagation of the longitudinal waves and solutions reflect the frequency modulationfeature as expected. This has been one of the most important phenomena in the propagation of nonlinear waves with practical applications on thefrequency change due to the material nonlinearity. Known changes of frequency will be important in examining the frequency response anddevelopment strategies in catching the signal which are being modulated due to the material effect.

Keywords:Keywords:Keywords:Keywords: nonlinear; longitudinal wave; homotopy analysis method; finite differenceAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported in part by grants from the National Natural Science Foundation of China (Nos. 10932004 &10772087) and the Doctoral Program Fund of Ministry of Education of China (No. 20093305110003).


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MECHANISMMECHANISMMECHANISMMECHANISMONONONONENERGYENERGYENERGYENERGYTRANSMISSIONTRANSMISSIONTRANSMISSIONTRANSMISSION CONTROLCONTROLCONTROLCONTROLININININ BEAMSBEAMSBEAMSBEAMS BASEDBASEDBASEDBASEDONONONONTHETHETHETHE

PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICTRANSDUCERSTRANSDUCERSTRANSDUCERSTRANSDUCERS

Tian-zhu XU1, Zhen-yu HUANG1*, Hai-li LIU1, Qun GAO2

1Department of Instrument Science and Engineering, Shanghai Jiao Tong University, Shanghai 2002402School of Mechanical Engineering, Shandong University, Jinan 250061

*Corresponding author, E-mail: [email protected]; Tel.: +86-21-34202725

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe piezoelectric transducer is popular in vibration control applications where it can work as not only sensors but also actuators due to itselectro-mechanical coupling property as well as the non-intrusive nature. Piezoelectric transducers connected with electrical impedance, which is calledpiezoelectric shunt damping, can be bonded to or embedded in composite structures for vibration suppression in flexible structures. Such methods donot require an external sensor, and if designed properly, may guarantee stability of the shunted system, seem as improving the damping of the system.For a large scale structure, such as a long beam and large plate, numerous piezoelectric transducers are required to provide good performance onvibration control. This, however, will greatly increase difficulties in realization of the system. A novel method, which controls vibration energy flowinstead of consuming energy by altering connected shunt impedance, is presented. Such method may be used in joints of large scale structures tocontrol the vibration propagation.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThis research is focused on the mechanism of energy transmission controlled by piezoelectric shunt damping in beams. A model of a beam attachedwith a piezoelectric sheet in the middle has been built first. The sheet connects with variable electrical impedance, which will influence the dynamicparameters of the structure. Vibration energy propagates from “dirty-side”, which is no-controlled side of the beam, to “clean-side”, which is controlled.Based on this model, the relationship between the wave reflection (transmission) coefficient and the electrical impedance can be studied to check thepossibility of the method, includes the adjustable frequency range and the effect of reflection. Furthermore, while vibration energy propagates fromboth sides of the beam, whether it’s possible to reflect the energy from dirty-side but transmit the energy from clean-side by using electrical impedanceis also discussed.ResultsResultsResultsResultsIt has been shown from simulation that, changing the electrical impedance of a piezoelectric sheet can influence the dynamic parameters of themechanical structures. So it is possible to create a “switch” to control the propagation of vibration energy between structures connected by apiezoelectric sheet. An adaptive circuit is also developed to realize the control purpose of excitations with variable frequencies. The experiment is alsodone to validate the results.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsTo control the propagation of vibration energy between structures connected by a piezoelectric sheet is probable. Due to the limitation ofelectro-mechanical coupling coefficient, piezoelectric sheet may not control large, heavy structures, but it may be used as the connector of thin, lightbeams or plates and provide good performance on vibration control.

Keywords:Keywords:Keywords:Keywords: piezoelectric; impedance; vibration control; energy transmission; reflection



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AAAAMODIFIEDMODIFIEDMODIFIEDMODIFIED SYNCHRONIZEDSYNCHRONIZEDSYNCHRONIZEDSYNCHRONIZED SWITCHSWITCHSWITCHSWITCH FORFORFORFORMULTI-FREQUENCYMULTI-FREQUENCYMULTI-FREQUENCYMULTI-FREQUENCYPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC

ENERGYENERGYENERGYENERGYHARVESTINGHARVESTINGHARVESTINGHARVESTING BASEDBASEDBASEDBASEDONONONONVOLTAGEVOLTAGEVOLTAGEVOLTAGE SWITCHINGSWITCHINGSWITCHINGSWITCHINGTHRESHOLDTHRESHOLDTHRESHOLDTHRESHOLD

Tian-li LUO, Tian-zhu XU, Hai-li LIU, Zhen-yu HUANG*Department of Instrument Science and Engineering, Shanghai Jiao Tong University, Shanghai 200240


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveOwing to the great reduction on power consumption of integrated circuits (ICs) and miniaturization during the past decades, the energy harvestingtechnique has gained much interest recently with the inspiration that more mobile devices could power themselves by scavenging the ambient energy indifferent forms. Noting that mechanical movement or vibration can be found everywhere in our daily life, it is one of the promising ambient sources tobe exploited. Generally speaking, any electromechanical transducer can be utilized to harvest vibration energy, but three transduction mechanisms, i.e.,piezoelectric, electromagnetic, and electrostatic, are most studied. Among generators based on these three mechanisms, the piezoelectric ones are thesimplest to fabricate; therefore, they are particularly suitable for implementation in Microsystems. Thus piezoelectric energy harvesting (PEH) is one ofthe most widely studied techniques.In piezoelectric energy harvesting (PEH), the technique named synchronized switch harvesting on inductor (SSHI) is usually used to enhance theenergy harvesting efficiency. The SSHI technique reverses the voltage on the piezoelectric element at all extreme voltage. This switching algorithm iseffective for single-frequency excitation. For multiple-frequency vibration, it will, however, reduce the energy converting in low-frequency excitationand waste much energy in the voltage invert. In order to effectively harvest the energy of multiple frequencies vibration, a modified SSHI approachbased on a voltage switching threshold is proposed.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn the modified SSHI approach, the voltage on the piezoelectric element just reverses when its value is higher than the switching threshold.Consequently, more energy is harvested in the low-frequency vibration as well as less energy is wasted due to the reduction of the switching numbers.The voltage threshold in a real system should be adjusted automatically according to the voltage level. Thus, the voltage threshold can be calculatedfrom latest several extreme voltage. The initial value of the voltage threshold is set to zero and updated after each switching action. Numericalsimulations were conducted in terms of different input vibration, i.e. several exciting frequencies in different frequency ratios and amplitude ratios.ResultsResultsResultsResultsResults show that the modified multi-modal SSHI can greatly enhanced the energy harvesting efficiency for multi-frequency vibrations. In order to testthe modified SSHI in experiments, a multi-mode piezoelectric energy harvester was fabricated and the switching action in the modified SSHI wasexecuted by an ultra-low-power MCU. The harvested energy was further to power the ultra-low-power MCU and a wireless temperature sensor.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsAccording to the simulation, the modified SSHI approach can greatly enhance the energy harvesting efficiency.

Keywords:Keywords:Keywords:Keywords: piezoelectric energy harvesting; SSHI; voltage threshold; multi-frequency



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DEDUCINGDEDUCINGDEDUCINGDEDUCINGANDANDANDANDVERIFYINGVERIFYINGVERIFYINGVERIFYINGTHETHETHETHE FREQUENCYFREQUENCYFREQUENCYFREQUENCYEQUATIONEQUATIONEQUATIONEQUATION SETSETSETSETOFOFOFOFDUAL-FREQUENCYDUAL-FREQUENCYDUAL-FREQUENCYDUAL-FREQUENCY

PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICTRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCER

Jia-he FU1, Han-ling MAO2*

1School of mechanical engineering, Guangxi University, Nanning 5300042Guangxi University, Nanning 530004

*Corresponding author, E-mail: [email protected]; Tel.: 13317800020

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveNow, sandwich piezoelectric ultrasonic transducer which mainly radiated ultrasonic from one end is usually used by ultrasonic cleaning and ultrasonicextraction, and generally, it only has one operating frequency. When the single frequency transducer works, it will produce standing waves in the liquidwhich would seriously impact on the effect of the ultrasonic. The use of multi-frequency transducer can well solve this problem, but, generally thecurrent design methods just use one operating frequency to determine the size at first, and then utilize the size to calculate the other frequency in turn.This design method is very complex, and it can not be used to design a multi-frequency transducer according to any two operating frequencies.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThis paper designs a new type of transducer, it has two operating frequencies and two ends with radiation. For obtaining two operating frequencies andtwo ends with radiation, the transducer has two groups of piezoelectric ceramic crystal heap. When the two operating frequencies are not workingsimultaneously or the mutual interference is relatively small, it can be considered that one piezoelectric ceramic crystal heap Is energized and theanother one is as a Mechanical vibrating body. By analyzing single-frequency working state, we can deduce a frequency equation; similarly anotherfrequency equation has been deduced. Then, put the two frequency equations together, we should get the frequency equation set of dual-frequencypiezoelectric transducer. At last, this paper design some dual-frequency piezoelectric transducers which has different two operating frequencies, andsolve the equation set to get dimensions, then, use ANSYS software to do modal analysis and frequency response analysis of the transducer model forverifying this method.ResultsResultsResultsResultsBy do modal analysis and frequency response analysis of the transducer model, the frequency equation set has been verified. According to this designmethod, we can design the piezoelectric transducer base on any two different frequencies on request, and the theoretical frequency is closer to the actualvalue.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe experiments show that this design method is feasible; we can use it to design the piezoelectric transducer base on any two different frequencies onrequest.

Keywords:Keywords:Keywords:Keywords: piezoelectric transducer; dual-frequency; frequency equation set; ANSYSAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the Guangxi Natural Science Fund (No. 0991069) and the subject for Guangxi Key Laboratoryof Manufacturing System and Advanced Manufacturing Technology.



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ACTIVEACTIVEACTIVEACTIVE STRUCTURALSTRUCTURALSTRUCTURALSTRUCTURALACOUSTICACOUSTICACOUSTICACOUSTIC CONTROLCONTROLCONTROLCONTROLOFOFOFOFAAAATHINTHINTHINTHIN SHELLSHELLSHELLSHELLUSINGUSINGUSINGUSING PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC

MATERIALMATERIALMATERIALMATERIAL

Li-jun LI*, Shi-jie ZHENGInstitute of Smart Materials and Structures, State Key Laboratory of Mechanics and Control of Mechanical Structures College of Aerospace Engineering,

Nanjing University of Aeronautics &Astronautics, Nanjing 210016


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveNoise pollution is one of four environmental pollutions, and acoustic radiation emitted by the structure vibration is the main source of noise. Numericalmethods have been introduced to compute the approximate solutions of structural-acoustic, and the standard finite element method is thewell-developed and widely-used numerical methods in solving these acoustic problems on limited field. Over the past decade, an amount of researchhas been devoted to noise reduction techniques. Classically, noise reduction by passive techniques is achieved by using sound absorbing materials, butpassive reduction methods are quite effective at high frequencies. Recent years, the emergence of new actuator mechanisms associated with smartmaterials has triggered the development of active structural acoustic control strategy. In the low frequency range, active techniques using piezoelectricmaterials, which has the following features: low power consumption, lightweight, flexibility, fast response time, are found to be an attractive alternativeor complementary tool.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, we first infer FEM formula of the coupled systems in the Cartesian coordinate system based on the Galerkin method, the elastodynamicequation, the electric charge equation, the Helmholtz equation and the boundary conditions. The negative-velocity constant gain feedback strategy,which means a voltage from the sensors is amplified and fed back into the actuators, is adopted to investigate the sound radiation. Based on abovetheory, we realize the procedure calculates to the problem using FORTRAN language. The eight-node solid-shell element, which adopts the enhancedassumed strain (EAS) method and the assumed natural strain (ANS) method, is used to analysis the structure, and the eight-node hexahedronisoparametric element is used to analysis the sound fields. The unsymmetrical coupling system is decoupling in left and right feature space, and theNew-Mark method and the mode superposition method are used to calculate the time response and the frequency response respectively.ResultsResultsResultsResultsThis paper investigates the acoustic radiation of an enclosed-cavity with one cylindrical panel mounted piezoelectric patches. First, the modalities of themode are analyzed by program and ANSYS respectively. Comparison of the simulation results demonstrates the accuracy of FEM program. Second, bycalculating the responses of the system in single mode to different gain with the New-Mark method, we can conclude that the active control of acousticradiation is successful. Last, we calculate the frequency response of sound pressure using the mode superposition method, and the result show that theactive control of the round radiation with piezoelectric materials is remarkable in the low frequency range.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn this paper, a enclosed-cavity, which a thin and shallow cylindrical panel coupling with a layer of piezoelectric materials backed by a rectangularparallelepiped shaped cavity, is investigated on the active structural-acoustic control using finite element method and negative-velocity feedbackstrategy. Simulation results verify the efficiency of piezoelectric materials in the active control of acoustic radiation.

Keywords:Keywords:Keywords:Keywords: active control; coupling of structure-acoustic; piezoelectric material; finite elementAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10872090, 11172129) and theFundamental Research Funds for Nanjing University of Aeronautics & Astronautics (No. NJ2010011). This financial support is gratefullyacknowledged.



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AAAAMICROREACTORMICROREACTORMICROREACTORMICROREACTORUSINGUSINGUSINGUSING SURFACESURFACESURFACESURFACEACOUSTICACOUSTICACOUSTICACOUSTICWAVEWAVEWAVEWAVEASASASASANANANAN ENERGYENERGYENERGYENERGYSOURCESOURCESOURCESOURCE

Yan ZHA, An-liang ZHANG*Department of Electrical Engineering, Ningbo University, Ningbo 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveIn recent years, microfluidic devices have been seen increasing application in DNA sequencing, protein analysis, single cell analysis, drug screening,and food safety due to their low cost, small size and reduced reagent consumption. A micro-reactor is an important operational unit in a microfluidicdevice. Compared to the microfluidic device working with continuous fluid, the microfluidic device working with a droplet has some advantages suchas higher precision, littler reagent consumption, more compact and lower cost. Thus droplet-based microreactors have attracted wide interest ofresearchers. However, lots of reactions can only occur at above room temperature, which needs a heating micro-system integrated into the microreator.In this paper, we present a new microreactor with SAW heating micro-system to overcome the disadvantages of reported microreactors. The heatingprinciple of the microreactor using SAW as energy source is given at first. Then, the fabrication of the presented microreactor and experimental setupare represented. The color development reaction and melting reactants experiments using the microreactor are also presented. And then, theexperimental phenomena are explained. Finally, the conclusion of the work is given.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe presented microreactor has three functional units, including a piezoelectric substrate with an IDT and a reflector, a sheet metal for heat transfer andtwo PDMS micro-vessels.When a RF signal with suitable frequency is applied to an interdigital transducer (IDT), surface acoustic waves (SAWs) can be excited byacoustic-electrical effect of piezoelectric material and then transport along the piezoelectric substrate. When hitting a microfluid on the piezoelectricsubstrate, the major part of the incident wave energy could radiate into the microfluid by Rayleigh angle θR and the temperature of the microfluid wasraised. The reactant in the PDMS micro-vessel was also heated.ResultsResultsResultsResultsSolid paraffin with 58-60 of melting point was used in the experiments to show heating effect of SAW. If only the solid paraffin in the microreactorcan be melted by SAW, which shows that the microreactor can raise reactant temperature to 58-60 from room temperature, the microreactor can alsobe used for biochemical reactions with less the temperature. A 6 mm×6 mm×0.07 mm copper sheet was used as sheet metal, and 10µl glycerin waspipetted into the PDMS micro-vessel with 4mm diameter on the piezoelectric substrate to ensure that the glycerin can contact with the copper sheet.0.0035 gram solid paraffin was then filled in top PDMS micro-vessel on the copper sheet. Increasing the RF signal power to 31dBm, the solid paraffincan still not be melted completely. Cooling the solid paraffin for 5min and increasing the RF signal power to 34dBm, the solid paraffin was melted after70s.A color development reaction of starch solution was also demonstrated using the microreactor. 4.5µ l mixed solution of 0.20mol/L KI, 0.01mol/LNa2S2O3 and 0.4% starch and 3µl 0.20mol/L (NH4)2S2O8 solution were pipetted into the PDMS micro-vessel on the 6 mm×6 mm×0.1 mm aluminumsheet. A RF signal was applied on an IDT on the piezoelectric substrate. The reaction time is decreased with RF signal power applied to the IDT, whichindicates that the temperature of the reaction solution has been raised with different degrees at different RF signal power.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsA new microreactor has been presented using SAW as energy source in this work. Glycerin microfluid was used to transfer the radiation SAW energyinto its temperature and then raised the temperature of reactant solution in the PDMS micro-vessel. The experiment of melting solid paraffin shows thatthe temperature of the reactant in microreactor can be raised 44 at least. The microreactor can be used in biological or chemical reaction, such asparts of immunity analysis, cell culture, organic synthesis and inorganic matter detection, where the reactant can occur only when the temperature of thereactant solution higher than room temperature. The microreactor can also be integrated into PDMS microchannel in a microfluidic device toimplement biochemical reaction.

Keywords:Keywords:Keywords:Keywords: microreactor; surface acoustic wave; interdigital transducer; PDMS micro-vesselAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the Science and Technology Department of Zhejiang province and Natural ScienceFoundation of Ningbo municipal in China under award number 2009R50025 and 2011A610108.



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INFLUENCEINFLUENCEINFLUENCEINFLUENCEOFOFOFOFBARIUMBARIUMBARIUMBARIUMCONTENTCONTENTCONTENTCONTENTONONONONTHETHETHETHE PROPERTIESPROPERTIESPROPERTIESPROPERTIESANDANDANDAND STRUCTURESTRUCTURESTRUCTURESTRUCTURE OFOFOFOFLOWLOWLOWLOW

TEMPERATURETEMPERATURETEMPERATURETEMPERATURE SINTEREDSINTEREDSINTEREDSINTERED BCZTBCZTBCZTBCZT LEAD-FREELEAD-FREELEAD-FREELEAD-FREE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC CERAMICSCERAMICSCERAMICSCERAMICS

Chun-hua GAO*, Xin-you HUANG, Zhi-wen ZHUSchool of Materials Science and Engineering, Jiangsu University, Zhenjiang 212013,China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric ceramics is a kind of important functional materials which can convert electric energy from mechanical energy. At present, the widespreaduse of piezoelectric ceramics is Pb (Ti, Zr) O3 lead-based piezoelectric ceramic materials. Compared with lead based piezoelectric ceramic materials,the piezoelectric properties of lead-free piezoelectric ceramics is a big gap. But lead free piezoelectric ceramics have pollution-free, without socialeffects of pollution, advantageous to environmental protection and advantage of environmental compatibility. The study of lead-free piezoelectricceramics is paid high attention by all countries. In recent years, researcher report successively BaTiO3 piezoelectric ceramics with high piezoelectricproperties and BaTiO3 piezoelectric ceramics was prepared by conventional solid state sintered method and analytical pure materials was used as rawmaterials, sintered temperature was above 1400. In this paper, the influence of Ba content on the properties and structure of low temperature sintered(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3(BCZT) series lead-free piezoelectric ceramics was studied and by conventional solid state method and TiO2 ischemically pure raw materials, other raw materials were analytical pure raw materials.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/Methods(Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) lead-free piezoelectric ceramics were prepared using a conventional solid state method. The influence of Bacontent on the crystal phase, surface microstructure and properties of the low temperature sintered (Ba0.85Ca0.15)(Zr0.1Ti0.9)O3 (BCZT) lead-freepiezoelectric ceramics were studied by scanning electron microscope(SEM) and X-ray diffraction(XRD) and other analytical methods. TiO2 waschemically pure raw materials, other raw materials were analytical pure raw materials. Low temperature sintered lead-free piezoelectric ceramics withhigh piezoelectric properties was obtained, the related mechanism was probed.ResultsResultsResultsResultsWith the increasing of the content of barium, ceramic grain size decreased gradually, the diffraction peaks of perovskite structure was obvious, therewas miscellaneous peak. With the increasing of the content of barium, the planar electromechanical coupling coefficient（kp）and the piezoelectric strainconstant（d33）and the thickness electromechanical coupling coefficient（kt）and the dielectric constant（εr）of low temperature sintered BCZT ceramicsall increased first and then decreased, dielectric loss（tanδ）of low temperature sintered BCZT ceramics decreased first and then increased. When thecontent of barium was 0.85 mol, the properties of low temperature sintered BCZT ceramics was optimum, which kp was 0.42, d33 was 87 pC/N, kt was0.046, tanδ was 0.013, εr was 2020, the sintered temperature was 1050.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsBecause the radius of Ca2+ (1.06 Å) was small than the radius of Ba2+ (1.43 Å), With the increasing of the amount of Ca2+ replace Ba2+ and thebarium content reduced, the bigger lattice distortion of low temperature sintered BCZT ceramics is produced and electric domain rotation is easy andthere are more orientation of electric domain along the direction of the electric field when polarization of low temperature sintered BCZT ceramics andthe barium content reduced, the piezoelectric properties of low temperature sintered BCZT ceramics increased when the barium content decreased.Electric domain rotation is difficult and there are less orientation of electric domain along the direction of the electric field when polarization and thebarium content further decreased, the piezoelectric properties of low temperature sintered BCZT ceramics decreased when the barium content furtherdecreased. With the increasing of the content of barium, the grain size of low temperature sintered BCZT ceramics decreased gradually, the diffractionpeaks of perovskite structure was obvious, there was miscellaneous peak. With the decreasing of the content of barium, the planar electromechanicalcoupling coefficient（kp）and the piezoelectric strain constant（d33）and the thickness electromechanical coupling coefficient（kt）and the dielectricconstant（εr）of low temperature sintered BCZT ceramics all increased first and then decreased, dielectric loss（tanδ）of low temperature sintered BCZTceramics decreased first and then increased. When the content of barium was 0.85 mol, the properties of low temperature sintered BCZT ceramics wasoptimum, which kp was 0.42, d33 was 87 pC/N, kt was 0.046, tanδ was 0.013, εr was 2020，the sintered temperature was 1050.

Keywords:Keywords:Keywords:Keywords: Lead-free piezoelectric ceramics; Calcium barium zirconate titanate; Low temperature sintering; Piezoelectric propertiesAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by Program of Science and Technology Support of Jiangsu Province (No. BE2008029), The workwas supported by Project of Combination of Producing, Learning and Studying of Guangdong Province and EducationDepartment(No.2011B090400027).


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STUDYSTUDYSTUDYSTUDYONONONON SIGNALSIGNALSIGNALSIGNALCRYSTALCRYSTALCRYSTALCRYSTALPHOTO-ELASTICPHOTO-ELASTICPHOTO-ELASTICPHOTO-ELASTICMODULATORMODULATORMODULATORMODULATORBASEDBASEDBASEDBASEDONONONONLITHIUMLITHIUMLITHIUMLITHIUM

NIOBATENIOBATENIOBATENIOBATE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICANDANDANDAND PHOTO-ELASTICPHOTO-ELASTICPHOTO-ELASTICPHOTO-ELASTIC EFFECTEFFECTEFFECTEFFECT

You-hua CHEN1,2*, Ji-long ZHANG1,2, Yan-chaoWANG 1,2, Li-fu WANG 1,2, Rui ZHANG1,2,Yuan-yuan CHEN1,2, Zhi-bin WANG1,2

1Key Laboratory of Instrumentation Science and Dynamic Measurement，North University of China，Taiyuan 030051，China2Engineering Technology Research Center of Shanxi Province for Opto-Electronic Information and Instrument，North University of China，Taiyuan 030051，China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveIn order to overcome the disadvantage of Kemp-type photo-elastic modulator such as low modulation efficiency, strict match size, bulky et al., weproposed a photo-elastic modulate mode which use LiNbO3 crystal piezoelectric properties to produce the effect of the photo-elastic.Statement of Contribution/MethodsAccording to the theory of piezoelectric vibration and Crystal optics principle, we analyzed the crystal orientation dependence of physical properties,and derived the relations of displacement and retardation amplitudes over voltage amplitude, then, the cut-type and the optical path was been optimized.The device was designed with dimensions 41 mm×7.7 mm× 17.1 mm in x-, y- and z-direction, 0°cutting angle(x-cut), z-axis for the optical path andelectrodes on the xz-surfaces offers basic modulation frequencies at 73.71kHz corresponding to the longitudinal oscillations in x- direction. Finally, thecorrelation experimental equipment was built for the experimental verification;ResultsResultsResultsResultsthe result shows that: the voltage amplitude to achieve a half-wave retardation amplitude is only ~1.6 V for 633nm wavelength, the modulation voltagereduced ~4 times Compared with the LiTaO3 signal crystal photo-elastic modulator whose cutting-type didn't been optimized .DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe SCPEM will have larger dynamic modulation range and lower modulation power dissipation; in addition, the light damage threshold of thisSCPEM will be high, and modulation frequency can be further improved till hundreds of kHz or several MHz. It has important application prospect inthe field of super-laser pulse modulation, super-speed interference modulation and so on.

Keywords:Keywords:Keywords:Keywords: lithium niobate; piezoelectric effect; cutting-type；single crystal; photo-elastic modulatorAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by Special Fund for Instrument of Natural Science Foundation of China (Grant No. 61127051),Cooperation Project of International Science and Technology (Grant No. 2012DFA10680), Cooperation Project of International Science andTechnology (Grant No. 2010XXX), Funding Task of Cooperation Project of International Science and Technology of Shanxi Province (Grant No.2010081038).



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CORRECTIONCORRECTIONCORRECTIONCORRECTION FACTORSFACTORSFACTORSFACTORS FORFORFORFORMINDLINMINDLINMINDLINMINDLIN PLATEPLATEPLATEPLATE EQUATIONSEQUATIONSEQUATIONSEQUATIONSWITHWITHWITHWITHTHETHETHETHE CONSIDERATIONCONSIDERATIONCONSIDERATIONCONSIDERATION

OFOFOFOFSTIFFNESSSTIFFNESSSTIFFNESSSTIFFNESSANDANDANDANDMASSMASSMASSMASS EFFECTSEFFECTSEFFECTSEFFECTS OFOFOFOFELECTODESELECTODESELECTODESELECTODES FORFORFORFOR SC-CUTSC-CUTSC-CUTSC-CUTQUARTZQUARTZQUARTZQUARTZ CRYSTALCRYSTALCRYSTALCRYSTAL

PLATESPLATESPLATESPLATES

Ji WANG*, Gui-jia CHEN, Wen-jun WANG, Rong-xing WUPiezoelectric Device Laboratory, School of Mechanical Engineering and Mechanics, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveMindlin plate theory has been playing a vital role in the analysis of high frequency vibration of quartz crystal resonators, but correction must be made atthe cut-off frequencies. However, with stiffness and mass effects of electrodes considered in the plate equations, correction factors are differentbetween the AT- and SC-cut quartz crystal.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe derived exact frequency equations of the infinite SC-cut quartz crystal plate covered by symmetric electrodes on both sides for thickness vibrationmodes at zero wavenumber. Since SC-cut quartz crystal has more elastic constants, the equations can be used with AT-cut quartz but not vice versa.With the known exact frequencies, we require the Mindlin plate equations have the same results at zero wavenumber, so we can obtain the correctionfactors. For different applications, we have obtained the correction factors with symmetric and natural methods.ResultsResultsResultsResultsAfter we obtained the correction factors, we have made curves fitting on the correction factors, for the relation between correction factors and the massratios for convenience in applications. The symmetric correction factors could be used in the finite element analysis and natural correction factorscould be used in analytical analysis.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsTo satisfy needs of practical applications of the Mindlin plate equations for the analysis of quartz crystal resonators, the mass and stiffness of thickelectrodes have to be considered in the analysis. With those factors we can obtain the accurate frequencies of thickness-shear vibrations of SC-cutquartz crystal plates were much more close to actually.

Keywords:Keywords:Keywords:Keywords: mindlin plate theory; correction factor; electrode; stiffness effectAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported in part by the national Natural Science Foundation of China (Grant Nos. 10932004 & 11072116)and the Ministry of Education of China (Grant No. 20093305110003). Additional support is provided by the K.C. Wong Magna Fund, and StudentResearch and Innovation Program of Ningbo University.


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FREEFREEFREEFREEVIBRATIONVIBRATIONVIBRATIONVIBRATIONOFOFOFOFFIXEDFIXEDFIXEDFIXED SUPPORTEDSUPPORTEDSUPPORTEDSUPPORTEDANDANDANDANDMULTILAYEREDMULTILAYEREDMULTILAYEREDMULTILAYERED

MAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTIC PLATESPLATESPLATESPLATES

Li-bo XIN1*, Zhen-dong HU1

1School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai, 200092


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveWith the increasing technological applications of piezoelectric and piezomagnetic materials in smart structures, the problems associated withmagneto-electro-elastic materials have gained considerable attention recently. This paper is aimed to study the free vibration of fixed supported layeredmagneto-electro-elastic plates.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, free vibration analysis of fixed supported layered magneto-electro-elastic plates has been carried out by using series solution and finiteelement method. The study is aimed to bring out the dynamic behavier of magneto-electro-elastic plates under different boundary conditions.ResultsResultsResultsResultsIn this paper, a finite element solution is derived for the free vibration of three-dimensional magneto-electro-elastic and multi-layered rectangular platewith fixed boundary conditions. On solving the vibration problem, the finite element method are proposed. This solution can be used to deal with thepiezoelectric, piezomagnetic, purely elastic problems, and provides an exact results of vibration problems. The special features can be helpful in theanalysis and design of magneto-electro-elastic composite materials.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsAccording to the analysis of sandwich piezoelectric and magnetostrictive plates, some features are concluded:1. The numerical examples are presented for piezoelectric, magnetostrictive and sandwich plates. It is observed that the frequencies under the fixed

boundary condition is higher than free boundary condition.2. The natural frequencies of the four cases are different, which shows that the piezoelectric and magnetostrictive effect can influence the vibration of

the plates.3. There exist some purely elastic modes which are not independent of the coupling coefficients. They can be identified by simply analysing the free

vibration of the purely elastic plate.4. The material properties and stacking sequences greatly influence the elastic displacements and electric and magnetic potentials. The results can

help design the material to satisfy the need in project.

Keywords:Keywords:Keywords:Keywords: finite element method; magneto-electro-elastic plate; free vibration; multilayered



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SHSHSHSHWAVESWAVESWAVESWAVES ININININ FUNCTIONALLYFUNCTIONALLYFUNCTIONALLYFUNCTIONALLYGRADEDGRADEDGRADEDGRADED PIEZOELECTRIC-PIEZOMAGNETICPIEZOELECTRIC-PIEZOMAGNETICPIEZOELECTRIC-PIEZOMAGNETICPIEZOELECTRIC-PIEZOMAGNETICMATERIALMATERIALMATERIALMATERIAL


Ruo-meng TIAN1,2*, Yan-ping KONG2, Jin-xi LIU1,2

1Department of Engineering Mechanics, Shijiazhuang Tiedao University, Shijiazhuang 0500432Institute of Engineering Mechanics, Beijing Jiaotong University, Beijing 100044


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric-Piezomagnetic composite materials not only realize the mutual transformation between electrical energy and magnetic energy, but alsohave electromechanical coupling and magnetomechanical coupling effect. The concept of functional gradient materials are applied to the theoreticaldesign and preparation of Piezoelectric-Piezomagnetic materials, then functional gradient Piezoelectric-Piezomagnetic materials can be gotten. Thefunctionally gradient material is a type of new material, whose properties vary with the change of space. By controlling gradient variation of materialparameter, the propagation behaviors of waves which are wanted can be obtained, which have a certain reference value in the design of acoustic wavedevice. Therefore, it has an actual meaning for investigating the propagation of elastic waves in functional gradient piezoelectric-piezomagneticmaterial.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, we analyze SH waves propagating in the layered plate structure consisting of a function graded piezoelectric layer and a piezomagnetichalf space. Using index method, we obtain the dispersion equation of the SH waves propagation for electrical short and open cases on the free surface.ResultsResultsResultsResultsThe results show that boundary conditions, gradient coefficient of functionally gradient materials and the thickness of the gradient layer have aremarkable effect on the phase velocities of the SH waves.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe phase velocities are calculated for different numerical examples to discuss the influences of boundary conditions, gradient coefficient offunctionally gradient materials and the thickness of the gradient layer on the propagation behaviors. The Conclusions show that if the wave numberremains the same, the wave velocity will increase with the lager change of the gradient of various material parameters in covering layer; and the wavevelocity will decrease with the increasing of cover thickness; but on electrical short boundary condition, The effects of the thickness changes ofcovering layer on the first mode could be ignored.

Keywords:Keywords:Keywords:Keywords: functionally graded material; piezoelectric material; piezomagnetic material; SH waves; dispersion relationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the Natural Science Foundation of China (No. 10972147).



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THETHETHETHEMULTICOUPLEDMULTICOUPLEDMULTICOUPLEDMULTICOUPLEDMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRIC EFFECTEFFECTEFFECTEFFECT ININININ

THREE-PHASETHREE-PHASETHREE-PHASETHREE-PHASETbTbTbTb1-x1-x1-x1-xDDDDyyyyxxxxFeFeFeFe2222//// Pb(ZrPb(ZrPb(ZrPb(Zr1-x1-x1-x1-xTiTiTiTixxxx)O)O)O)O3333/NdFeB/NdFeB/NdFeB/NdFeB BIMORPHBIMORPHBIMORPHBIMORPH LAMINATESLAMINATESLAMINATESLAMINATES

Zeng-ping XING1*, Kai XU1,2, Bin HE1

1Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, P.R. China, 3152012College of Mechanical Engineering & Mechanics, Ningbo University, Ningbo, P.R. China, 315201


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveMagnetic torque could induce giant magnetoelectric(ME) effect. Here we will show that the magnetic torque could tune the magnetoelectric effect indifferent magnetic DC bias, and it was found that the magnetic torque could enhance the conventional magnetoelectric effect under some specificcondition. This research has provide a way of enhanced the conventional magnetoelectric effect.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsMulticoupled magnetoelectric (ME) effect originated from the interaction of magnetostriction, magnetic-torque and piezoelectricity was proposed. Athree-phase Tb1-xDyxFe2/Pb(Zr1-xTix)O3/NdFeB bimorph laminates with this mechanism was designed and investigated. We found that the magnetic DCbias could tune the multicoupling and lead to an enhancement or attenuation in ME effect. The ME voltage coefficient could be enhanced by a factor of2.6 times (or 2.2 times for practical device construction) that of a conventional bimorph ME device. This research has provided a sight of designingbetter ME devices with the multicoupling consideration.ResultsResultsResultsResultsThe ME voltage coefficient could be enhanced by a factor of 2.6 times (or 2.2 times for practical device construction) that of a conventional bimorphME device.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsMagnetic torque could helps to enhance the conventional magnetoelctric effect. We will supply more in full paper.

Keywords:Keywords:Keywords:Keywords: magnetoelectric effect, magnetic torque, multicouplingAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported by NSFC (No. 11004207), Ningbo Natural Science Foundation (No. 2010A610181) andNingbo Science and Technology Innovation Team (No. 2011B82004). We also gratefully thank the suggestion from Prof. Dwight Viehland in VirginiaTech, Blacksburg, VA, USA, 24061.



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REVERBERATION-RAYREVERBERATION-RAYREVERBERATION-RAYREVERBERATION-RAYANALYSISANALYSISANALYSISANALYSIS OFOFOFOFTIMOSHENKOTIMOSHENKOTIMOSHENKOTIMOSHENKOBEAMBEAMBEAMBEAMONONONON ELASTICELASTICELASTICELASTIC FOUNDATIONFOUNDATIONFOUNDATIONFOUNDATION

WITHWITHWITHWITHARBITRARYARBITRARYARBITRARYARBITRARYDYNAMICDYNAMICDYNAMICDYNAMIC LOADINGSLOADINGSLOADINGSLOADINGS

Ji-qing JIANG1*, Xin-jiang WEI1,2, Gui-ru YE2

1Department of Civil Engineering, Zhejiang University City College, Hangzhou 3100152Department of Civil Engineering, Zhejiang University, Hangzhou 310058


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe dynamic analysis of beams on elastic foundation is very important in many engineering fields, especially in civil engineering for soil/structureinteraction problems. Different beam theories and foundation models have been adopted to deal with this problem. For beams with smalllength-to-height ratio and embedded frames, the shear effect should be considered.There are two kinds of approaches for solving this topic, the exact solution method and the approximate method. The former is based on the differentialgoverning equation, but it is hard to deal with the complex situations. As an approximate method, the FEM is very powerful in modeling butcomputational expansive for solving wave propagation or high-frequency problems.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe MRRM adopted in this paper is based on the continuum model and has been applied for many dynamic problems. The Fourier transform isperformed and the wave expressions are derived in the frequency domain. Dual local coordinate systems are introduced for each beam element. Byconsidering the equilibrium and boundary conditions, the scattering relation is first obtained. For solving all of the unknown coefficients, the phaserelation due to the dual local coordinates is also derived. Combine these two formula we can finally obtain all of the dynamic characteristics andresponses.ResultsResultsResultsResultsIn numerical examples, the uniform and nonuniform elastic foundation beams are both analyzed. The frequencies and wave responses under arbitraryloadings are obtained. By comparing with the known results in the literature, we prove the accuracy of the present method. The effects of nonuniformfactors on dynamic characteristics are also analyzed.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe MRRM provides a uniform formula for dynamics of Timoshenko beams resting on elastic foundation. It is found that the present method can beeasily extended to nonuniform or embedded frame structures, and is accurate and stable in numerical calculation.

Keywords:Keywords:Keywords:Keywords: reverberation-ray matrix method; dynamic; timoshenko beam; elastic foundationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by Zhejiang Provincial Natural Science Foundation of China (No. LQ12E08009), the NationalNatural Science Foundation of China (No. 51278463 and 10972196), and the National Project of Scientific and Technical Supporting Programs fundedby the Ministry of Science & Technology of China (No. 2009BAG12A01-A03-2). Special thanks are given to Prof. Wei-qiu Chen for his valuablesuggestion and instruction.



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2D2D2D2DANDANDANDAND 3D3D3D3D GREENGREENGREENGREEN’’’’SSSS FUNCTIONSFUNCTIONSFUNCTIONSFUNCTIONS FORFORFORFOR PYROELECTRICPYROELECTRICPYROELECTRICPYROELECTRICMEDIAMEDIAMEDIAMEDIA

Peng-fei HOU*, Jie TONG, Hai-yang JIANGDepartment of Engineering Mechanics, Hunan University, Changsha 410082, PR China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric ceramics and piezoelectric polymers, which are extensively utilized in smart structures and intelligent system, all belong to pyroelectricmaterials. Rao and Sunar (AIAA Journal, 1993, 31: 1280-1284) pointed out that temperature variation in the piezoelectric material could affect theoverall performance of a distributed control system. Therefore, in-depth investigation on electro-thermo-mechanical coupling behavior is significant.Green’s functions play an important role in electroelastic analyses of pyroelectric media. However, most works available on this topic are on case ofidentical temperature.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on the 2D and 3D general solution of pyroelectric media, which is expressed in harmonic functions, and employing the trial-and-error method,the 2D and 3D Green’s function for a steady line heat source and a steady point heat source in semi-infinite, infinite and two-phase pyroelectric planeand media is presented by newly induced harmonic functions with undetermined constants. The corresponding coupled field can be obtained bysubstituting these functions into the 2D and 3D general solution, and the undetermined constants can be obtained by boundary conditions, continuousconditions and equilibrium conditionsResults/Results/Results/Results/ DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe 2D and 3D Green’s function for a steady line heat source and a steady point heat source in semi-infinite, infinite and two-phase pyroelectric planeand media are presented completely. And all the components of coupled field can be obtained in full fields. Because all the obtained solutions arepresented in terms of elementary functions, it is very convenient to use.

Keywords:Keywords:Keywords:Keywords: 2D; 3D; Green’s function; semi-infinite; infinite; two-phase; pyroelectricAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 51107110) and Natural ScienceFoundation of Zhejiang Province (No. Y1100581).



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ADVANCESADVANCESADVANCESADVANCES ININININ DESIGN,DESIGN,DESIGN,DESIGN, GROWTHGROWTHGROWTHGROWTHANDANDANDANDAPPLICATIONAPPLICATIONAPPLICATIONAPPLICATIONOFOFOFOFPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC CRYSTALSCRYSTALSCRYSTALSCRYSTALSWITHWITHWITHWITH

LANGASITELANGASITELANGASITELANGASITE STRUCTURESTRUCTURESTRUCTURESTRUCTURE

Yan-qing ZHENG*, Su-xian CUI, Jian-jun CHEN, Xiao-niu TU, Jun XIN, Hai-kuan KONG, Er-wei SHIShanghai Institute of Ceramics, Chinese Academy of Sciences, Jiading, Shanghai 201800, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveCrystals with langasite structure consist of more than one hundred compounds. Only about 20 compounds are grown and characterized. It will takelong time to characterize and sieve the new compounds by traditional method.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this work, we first use first-principles calculation to simulate the crystal structure of 29 ordered langasite compounds and then forecast theirpiezoelectric related properties including dielectric constants, elastic constants, piezoelectric coefficients and electromechanical coefficients.The calculations were carried out using the ABINIT code package. All calculations were at zero temperature.ResultsResultsResultsResultsAlthough the absolute values have difference as large as 1.4 times between theoretical and experimental ones, it is found that the relative trend betweendifferent crystals is correct. Four known ordered crystals including SNGS, STGS, CTGS, CNGS, and several novel crystals including BTGS, CTAS,CNAS were grown by Czochralski method and characterized at room temperature and at high temperature from 400 to 900 °C. The trend of theresistivity from low to high is SNGS < CNAS < STGS < CNGS < CTAS < CTGS for temperature ranging from 400 to 700°C.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe experimental results of piezoelectric properties verified the validity of theoretical forecast and that errors between experimental and theoreticalresults were in reasonable range. Gallium-free crystals show good prospect in application of piezoelectric sensors, combining the advantages of lowcost of raw materials and high performance. More efforts should be paid to the growth of these novel crystals.

Keywords:Keywords:Keywords:Keywords: langasite; piezoelectricity; crystals; first-principlesAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 50772121 and 50802104) and theKnowledge Innovation Program of Chinese Academy of Science under Grand No. KGCX-2-YW-206.


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RESONANTRESONANTRESONANTRESONANTGIANTGIANTGIANTGIANTMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRICMAGNETOELECTRIC EEFFECTEEFFECTEEFFECTEEFFECTOFOFOFOFPIEZOELECTRIC/MAGNETPIEZOELECTRIC/MAGNETPIEZOELECTRIC/MAGNETPIEZOELECTRIC/MAGNET

COMPOSITESCOMPOSITESCOMPOSITESCOMPOSITES

Kai XU1,2, Bin HE1, Jian-ke DU2, Zeng-ping XING1*

1Key Laboratory of Magnetic Materials and Devices, Ningbo Institute of Material Technology and Engineering, Chinese Academy of Sciences, Ningbo, P.R. China, 3152012Piezoelectric Device Laboratory, School of Mechanical Engineering and Mechanics, Ningbo University, 818 Fenghua Road, Ningbo, China 315201


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe Magnetoelectric (ME) effect has drawn much focus with the giant application potential in magnetic sensors, energy transformation, multiferroicmemory, Electrically Assisted Magnetic Recording (EAMR) and other fields, which became one of the central research issues around the world inrecent years. Comparing with the traditional ME devices consisting of piezoelectricity material and piezomagnetic material, the piezo-bimorph /magnetones with the new magnet moment mechanism have the advantages of higher magnetic coefficient, more stable performance, stronger orientationdetectable, and lower cost.The piezoelectricity /magnet laminate composites has dramatically enhanced ME effect that could reach to 2100V/cm.Oe than any others MEcomposites when operating around bending resonance frequency. But the resonant physical mechanism of piezoelectricity /magnet laminate compositesME effect hasn’t revealed and designated. It’s essential that the ME torque (MET) resonant effect of piezo-bimorph /magnet composites should betheoretical calculated and experimental confirmed.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe giant ME effect generated by the coupling of piezoelectricity and magnetic torque in piezoelectricity /magnet composites has been investigated. Toevaluate and predict the ME composites performance at the resonance situation, we’ve derived the theoretical analysis for Pb(Zr1-xTix)O3/ NdFeBdevice model, basing on piezoelectric principle and mechanical vibration theory.Besides, to verify the theory prediction, some relevance ME torque experiments have been preceded and five group dimension of 20mm, 22mm,24mm ,26mm, 28mm length samples have been fabricated with the same other parameters that the piezoelectricity bimorph thickness is 0.6mm and theNdFeB diameter and thickness are 8mm and 3mm，respectively.ResultsResultsResultsResultsThe relation between ME coefficients and frequency expressions of ME piezoelectricity /magnet composites has been acquired from the ME torque

theory model as follows:

)]cos(cosh1sin(sinh[3

11

2

33

031 klklklklklbhMdV −++−−=

ααα

ε）

The calculated results show that the ME coefficients is proportional to the piezoelectricity constant d31 and NdFeB magnetic moment M0 defined by the

residual magnetization intensity m and the imposed AC magnetic field flux density B, and inverse proportional to the wideness , thickness and

equivalent dielectric permittivity 33ε of PZT cantilever. The most significant is that the ME device resonant frequency is piezo-bimorph length

inverse-square dependence. The testing data of vary dimension samples is coincidental with theory predicted ones that the first bending vibration

resonance frequencies of ME composites samples are about 108.55Hz,123.3 Hz,143.3 Hz,167.42 Hz,201.72Hz and for the length 28mm, 26mm,

24mm ,22mm, 20mm respectively. Both calculated and experimental data indicate that the ME resonance voltage coefficients and the resonance

frequency could be adjusted by changing the sample’s dimension.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsResonant giant magnetoelectric torque effect of the piezo-bimorph/magnet composite has been investigated theoretically, experimentally. The relationsbetween the ME voltage and the geometry, materials properties, outside excitation frequency were derived. The theoretical calculation shows that theME voltage is frequency independence, which is smooth and constant at disresonance and reaches to maximum at resonant, while the ME deviceresonant frequency is piezo-bimorph length inverse-square dependence. Our experiments confirmed these derived predictions. These researches haveextended the giant ME effect from the traditional magnetostrictive/piezoelectric system to a common wider system including magnet/piezoelectric,provided a guide of designing better MET devices, and showed promising in constructing low cost and zero power consumption magnetic field sensorsor energy harvesters.

KeywordsKeywordsKeywordsKeywords:::: magnetoelectric effect; equivalent circuit; piezoelectricity; resonanceAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported by NSFC (Grant No. 11004207), Ningbo Natural Science Foundation (Grant No.2010A610181) and Ningbo Science and Technology Innovation Team (Grant No. 2011B82004).


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AAAA CANCANCANCANMETHODMETHODMETHODMETHODTOTOTOTO IMAGEIMAGEIMAGEIMAGETHETHETHETHEQUANTITATIVEQUANTITATIVEQUANTITATIVEQUANTITATIVE BONDINGBONDINGBONDINGBONDING STRENGTHSTRENGTHSTRENGTHSTRENGTHATATATAT THETHETHETHE BONDEDBONDEDBONDEDBONDED

SOLID-SOLIDSOLID-SOLIDSOLID-SOLIDSOLID-SOLID INTERFACEINTERFACEINTERFACEINTERFACE

Jian-jun CHEN*, De ZHANG, Yi-wei MAOThe Institute of Acoustics, Key Laboratory of Modern Acoustics, Nanjing University, Nanjing 210093, P.R.China

*Corresponding author, E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveDue to the massive applications of multilayered composite materials in material industry, aviation industry and other consumer industries, it becomes animportant work to carry on the non-destructive evaluation to the security of composite materials in use. The reliability of a composite material is mainlydecided by the bonding strength of its bonded interfaces. Therefore the examination of the quantitative bonding strength at the interface becomes thehot spot of the current research and application.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWhen a longitudinal acoustic wave propagates through a gap between solids, it causes CAN (Contact Acoustic Nonlinearity) phenomenon because twosurfaces of the gap are mutually collided due to the acoustic vibration. In practice, the bonded interface is non-uniform and there are lots of nanometerlevel micro-cracks in it. The existence of micro-cracks seriously influences the bonding strength of the composite. A CAN parameter defined in thispaper is very sensitive to the bonding strength and can be used to obtain the quantitative value of the bonding strength at the interface. After thevibration amplitude of incident focusing wave at the bonded interface was calculated, the standard bonding strength with complete bonding state wasestablished by tension test and CAN parameter is calibrated, the quantitative imaging of the bonding strength is obtained by CAN microscope inexperiments.

ResultsResultsResultsResultsThe quantitative contours of the bonding strength for two samples are shown in this paper. Compared with their optical photos, they are similar witheach other. From the images, the positions with weak bonding strength could be easily located, which can be used to decide whether the material couldbe employed continuously.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn summary, we can obtain the contour of the quantitative value of the bonding strength by the CAN microscopy and we have testified that the bondingstrength between the bonded solid-solid structures can be clearly described by the CAN parameter from the theoretical analysis and experimentalresults.

Keywords:Keywords:Keywords:Keywords: bonding strength; quantitative imaging; contact acoustic nonlinearity; composite materialAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11174144).



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ANALYSISANALYSISANALYSISANALYSISANDANDANDANDDEVELOPMENTDEVELOPMENTDEVELOPMENTDEVELOPMENTOFOFOFOFTHETHETHETHE PLATEPLATEPLATEPLATE----ATTACHEDATTACHEDATTACHEDATTACHED CYLINDRICALCYLINDRICALCYLINDRICALCYLINDRICAL

ROTARYROTARYROTARYROTARY----LINEARLINEARLINEARLINEAR ULTRASONICULTRASONICULTRASONICULTRASONICMOTORSMOTORSMOTORSMOTORS

Ting-hai CHENG*, Xiang-dong GUO, Gang BAO, Han GAO, Cheng-feng XIAO

School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150080, China

* Corresponding author, E-mail: [email protected]; Tel.: +86-0451-86413446-233

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUltrasonic motor as a new type of actuator has been widely investigated for several decades, and mainly utilizes the inverse piezoelectric effect ofpiezoelectric ceramics to excite the stator to gain a micro vibration in ultrasonic frequency range. Acting as a direct-driving motor, ultrasonic motorrealizes the transition from electric energy to mechanical energy by the friction coupling of stator and rotor. Compared to conventional electromagnetmotor, ultrasonic motor has some advantages such as large torque at low velocity, quick dynamic response, high position accuracy, interferenceimmunity of magnetic field, and so on.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsPiezoelectric element is the core component of ultrasonic motor utilized to transform electric energy into mechanical energy. So, the exciting mode ofpiezoelectric element has a significant influence on the output characteristics of ultrasonic motor. In this paper, the vibration characteristics ofplate-attached cylindrical rotary-linear ultrasonic motor were analyzed in theoretically and simulated by finite element analysis. In detail, the influenceof exciting position and length of PZT plates on the stator output performance were researched. Simulation confirmation was accomplished totheoretical results by finite element analysis.

ResultsResultsResultsResultsOn the basis of theory and simulation results, two plate-attached cylindrical rotary-linear ultrasonic motors with different flight leads of driving screwthread pair were developed, whose stators adopt the hollow square cylindrical structure and first bending vibration mode. A testing system based onvirtual instrument was realized and the prototype motors were tested. One of the prototype motors is achieved and the output velocity with 0.5 N load is6.3 mm/s, the maximum output force is 4.5 N, and the maximum output power is 6.6 mW at a working frequency of 19.70 kHz and a peak-peakexciting voltage of 100 V.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsTwo plate-attached cylindrical rotary-linear ultrasonic motors based on the first bending vibration mode were investigated both in theoretically andexperimentally. The simulation confirmations were accomplished to the theoretical results by the finite melement method. The logical plate location isat the bending vibration wave loop. Increasing the total length of PZT plates plays a crucial role in improving the output characteristics of motor. Butthe length should not be larger than the distance between the two vibration nodes in terms of fixing. At last, a smaller flight lead of driving screw threadpair between rotor and stator is conducive to improve the output force.

Keywords:Keywords:Keywords:Keywords: ultrasonic motor; bending vibration; rotary-linear motion; virtual instrumentAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 51075080).


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ANANANANANALYSISANALYSISANALYSISANALYSIS OFOFOFOFFREQUENCY-TEMPERATUREFREQUENCY-TEMPERATUREFREQUENCY-TEMPERATUREFREQUENCY-TEMPERATURE RELATIONSRELATIONSRELATIONSRELATIONS OFOFOFOFAAAAQUARTZQUARTZQUARTZQUARTZCRYSTALCRYSTALCRYSTALCRYSTAL

TUNINGTUNINGTUNINGTUNING FORKFORKFORKFORK

Ji WANG*, Xiang-Wu XU, Zhen WANGPiezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, Ningbo University,

818 Fenghua Road, Ningbo, Zhejiang 315211, China

* Corresponding author, E-mail:[email protected]; Tel.: 0574-87600467

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveTuning fork-type quartz crystal resonators are widely used as stable frequency sources of timing pulse generator with very low power consumption andvery small size not only in the quartz-driven wristwatch but also in the portable and personal communication devices. The tuning fork-type quartzcrystals are favored because typical requirements are satisfied, such as low frequency for low battery power consumption and minimal frequencychange with temperature and time after thermal or mechanical shock. Further improvement and optimization of turning fork resonators requireaccurate analysis of vibrations under the influences of bias fields such as the temperature through general theory of the thermal effect of quartz crystals.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, we study the thermal effect of tuning fork-type resonators with the known incremental thermal fields theory which was intended for thequartz crystal plate resonators with the consideration of temperature effect in cubic terms. The tuning fork resonator is considered as a cantileverbeam with thermal elastic constants for analytical solutions. The purpose of such approach is to demonstrate the effectiveness of the incrementalthermal field theory for possible improvement of analysis of tuning fork resonators which are subject to refinement in many emerging applications. Itis essential to utilize the effective fundamental theory of quartz crystal resonators for the vibrations of tuning fork which functions at differentfrequency and modes.ResultsResultsResultsResultsWith thermal elastic constants of quartz crystals, we can get the frequency-temperature characteristics of tuning fork resonators in the range of -50 to100. Using the cantilever model, we have the frequency-temperature relations similar to earlier analysis and measurements. It provides thestarting point of refined analysis with the thermal effect through incremental thermal field theory. Further improvements can be obtained through thecoupling of vibration modes and actual boundary conditions related to the tuning fork structures.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsPreliminary analysis of the thermal effect of tuning fork resonators of quartz crystal is carried out with the incremental thermal field theory andcantilever beam model. Consistent results on the vibration frequency of dominant mode are obtained and comparable to actual measurements. Thiswill enable us to improve the current analysis of tuning fork resonators with the refined thermal elastic constants for accurate predictions of vibrationfrequencies and mode couplings.

Keywords:Keywords:Keywords:Keywords: tuning fork; frequency-temperature; Euler-Bernoulli beamAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported in part by the national Natural Science Foundation of China (Grant Nos. 10932004 &11072116) and the Ministry of Education of China (Grant No. 20093305110003). Additional support is provided by the K.C. Wong Magna Fund ofNingbo University, and Student Research and Innovation Program of Ningbo University.


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ANALYSESANALYSESANALYSESANALYSES ONONONONDISPERSIONDISPERSIONDISPERSIONDISPERSIONANDANDANDAND EXCITATIONEXCITATIONEXCITATIONEXCITATION FEATURESFEATURESFEATURESFEATURES OFOFOFOFSYMMETRICSYMMETRICSYMMETRICSYMMETRIC GUIDEDGUIDEDGUIDEDGUIDEDWAVESWAVESWAVESWAVES

ININININAAAA FLUID-FILLEDFLUID-FILLEDFLUID-FILLEDFLUID-FILLED CYLINDRICALCYLINDRICALCYLINDRICALCYLINDRICALSHELLSHELLSHELLSHELL

Xi-qiang LI*, Hao CHEN, Xiao HE, Xiu-ming WANGState Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveTo develop a new calibration standard of acoustic logging, studies on the wave propagation in a fluid-filled cylindrical shell are of great significance. Itis known that the higher orders of symmetric modes have “plateau” characteristics. The velocities of the first-arrival wave extracted by theSlowness-Time-Coherence (STC) method well agree with the values on the dispersion curves in the “plateau” range. In this article, we will makefurther analyses on cylindrical guided waves and try to explain this phenomenon.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsOn the basis of all poles of the acoustic function, we obtain the phase and group velocity dispersion as well as excitation intensity curves. We cantherefore illustrate the propagation features of each mode and explain the phenomenon mentioned above.ResultsResultsResultsResults1. When the frequency of source is low enough, the fundamental mode is excited and dominant. Thus the velocity of the head wave extracted by theSTC method is always lower than the sonic speed in the fluid.2. When the frequency of source becomes higher and is contained in the “plateau” range, the first-arrival wave is not others but the mode whichowns “plateau” characteristic. The velocity of the head wave well agrees with the phase velocity in the “plateau” range.3. When the source frequency is located in any range between two “plateaus”, the first-arrival wave is nearly the sum of two modes who havealmost the same excitation intensities and group velocities. Coincidentally, the average phase velocity of the two modes is very near the “plateau”velocity.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsWhen the source frequency is high enough, the phase velocity of the first-arrival wave is always a definite value. That value is determined by thephysical and geometrical parameters of the model. Such a phenomenon can be applied for the calibration of sonic logging tools.

Keywords:Keywords:Keywords:Keywords: guided wave; symmetric mode; dispersion; excitation spectrumAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Grant No.11274341, No. 11134011 andNo. 41204099) and the Project of Innovation and Prospection in Institute of Acoustics, Chinese Academy of Sciences.



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DIPOLEDIPOLEDIPOLEDIPOLE SOURCESOURCESOURCESOURCEMISMATCHMISMATCHMISMATCHMISMATCHANDANDANDAND ITSITSITSITS EFFECTSEFFECTSEFFECTSEFFECTS ONONONON SONICSONICSONICSONIC LOGGINGLOGGINGLOGGINGLOGGING

Hao CHEN 1*, Xiu-ming WANG1, Xiao HE1

1 State Key Lab of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveA dipole source of a sonic logging tool, especially of a logging-while-drilling tool, is usually composed of two independent monopole sources withopposite phases. In reality, those two monopoles should have equal amplitudes. But this assumption can seldom be insured in the harsh environment ofdownhole. The amplitude mismatch of the dipole source will definitely lead to a more complex wavefield. Therefore, investigation on the directionalpatterns and the sonic logging responses to a mismatched dipole is necessary. How does the dipole mismatch influence the source directional pattern?And will this mismatch make effects on the receiver responses of the logging tool? We are going to answer these questions in the article.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsTo investigate the response excited by a mismatched dipole source, we numerically simulate the acoustic wave in an infinite fluid medium using a finitedifference code. A series of microphones with equal intervals is placed and each is a certain distance from the source. The wave energy can beevaluated from the frequency-domain integration. A plot of the directional pattern of a dipole source is obtained by gathering all receiver data in polarcoordinates. Dependence of the directional pattern on the source frequency is also discussed.The next objective of this study is to evaluate the effect of the dipole source mismatch on the sonic logging. In practice, a dipole logging tool has twoarrays of receivers which are mounted at opposite azimuth on the tool and has the same orientation as the source. The synthetic responses to a dipolecan be modeled by subtracting the records of one array from the other. And we can see the comparison of waveforms from the dipole sources withmismatches of various degrees.ResultsResultsResultsResultsThe numerical results of this study can be summarized as follows.(1) The plot of directional pattern for an ideal dipole is symmetric while that for a mismatched source is totally asymmetric. The source frequency caninfluence the shape of the contour. The numerical results are in excellent agreement with those of acoustic experiments in the water pool.(2) Comparing the responses to an ideal dipole with those to a mismatched dipole in a same formation, it is revealed that the phases and the shapes ofthe synthetic full waves are the same. For example, the waveform from a 2:1 mismatched dipole is exactly 1.5 times in amplitudes compared to thatfrom a 1:1 ideal dipole. These results are obtained under the assumption that the logging tool is located on the borehole axis and the receivertransducers are ideally matched.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe directional patterns and sonic logging responses of a mismatched dipole source are studied. The mismatch of a source will cause the asymmetry ofthe wave energy distribution but will not influence the phases of receiver signals of dipole sonic logging.

Keywords:Keywords:Keywords:Keywords: dipole; mismatch; logging; acousticsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Grant No. 11134011 and No. 41204099)and the Project of Innovation and Prospection in Institute of Acoustics, Chinese Academy of Sciences.



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MEASUREMENTMEASUREMENTMEASUREMENTMEASUREMENTOFOFOFOFTHETHETHETHEACOUSTICALACOUSTICALACOUSTICALACOUSTICALFIELDFIELDFIELDFIELD CHARACTERISTICCHARACTERISTICCHARACTERISTICCHARACTERISTIC OFOFOFOFPHASEDPHASEDPHASEDPHASEDARRAYARRAYARRAYARRAY

TRANSDUCERTRANSDUCERTRANSDUCERTRANSDUCER

Chun-guang XU1,2, Ming-kai DENG 1,2*, Ding-guo XIAO1, 2, Liu YANG1,2, Hui-ling REN1,2

1School of mechanical engineering, Beijing Institute of Technology, Beijing 1000812Key laboratory of fundamental science for advanced machining,Beijing Institute ofTechnology,Beijing 100081

*Ming-kai DENG, E-mail: [email protected]; Tel.: 010-68918436

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAs an advanced NDT technique, the ultrasonic phased array technique is widely used in the fields of aerospace, mechanics, chemistry, petroleum andnuclear industry, etc. Ultrasonic phased array transducer is one of the key devices in the ultrasonic phased array testing system and the characteristics ofthe transducer could make great impact on the testing system. But quit a few un-calibrated ultrasonic phased array transducers are serving inlaboratories and industrial testing sites, leading inaccurate results. So measuring the characteristics and calibrating the ultrasonic phased arraytransducer become quit essential.Acoustic field characteristic is a key factor of the ultrasonic transducer and many acoustic field measuring methods have been studied. This paperintroduces an advanced measuring method to get the acoustic field characteristic of the phased array transducer by means of using hydrophone. Thismethod has been mentioned both in ASTM E 1065-99（2003）“Standard Guide for Evaluation Characteristics of Ultrasonic Search Unit and BSEN12668-1～3:2000～2001 Non-destructive Testing-Characterization and Verification of Ultrasonic Examination Equipment-PartⅡ: Probes.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on a new acoustical scanning method which is appropriate for the ultrasonic phased array transducer, a new measuring systemfeatures the hydrophone and rapid scanning speed with high accuracy is introduced. In this measuring system, a signal transformationcircuit and a synchronization guarantee technique are designed to ensure the synchronization between excitation and data acquisition.Certain experiments are conducted at different focal length, deflection angle and excitation element numbers respectively to test thesystem and verify the method.ResultsResultsResultsResultsHigh definition acoustic field images which parallel the acoustic axis of transducer are obtained, combined with the acoustic field analysis, thefollowing results can be found: Firstly, differences between setting parameters and the measuring parameters of the system are limited; Secondly, withthe increase of the deflection angle, focusing effect and the acoustic beam energy are weakened remarkably; Thirdly, focusing effect is strengthened asthe excitation element numbers increase.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe new scanning acoustic method features hydrophone is appropriate for measuring the acoustic field characteristic of the ultrasonic phased arraytransducer. The test and verify experiments show that focusing effect and acoustic beam energy can be affected remarkably by the deflection anglewhile focusing effect can also be adjusted by the excitation element numbers.

Keywords:Keywords:Keywords:Keywords: ultrasonic phased array transducer; acoustical field characteristic; hydrophone; measurement systemAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National defense science and industry bureau of China.



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GROWTHGROWTHGROWTHGROWTHHABITSHABITSHABITSHABITS OFOFOFOFDOPEDDOPEDDOPEDDOPEDANDANDANDANDUNDOPEDUNDOPEDUNDOPEDUNDOPED LANGATATELANGATATELANGATATELANGATATE SINGLESINGLESINGLESINGLE CRYSTALSCRYSTALSCRYSTALSCRYSTALS

Xiao-niu TU, Yan-qing ZHENG, Yi-fan TU, Kai-nan XIONG, Er-wei SHIShanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800*Corresponding author, E-mail: [email protected]; Tel.: 021-69987662

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveLangatate (La3Ga5.5Ta0.5O14, LGT) single crystal can be used at high temperature. It is a promising material for high temperature acoustic wavedevices and sensors in applications fields of the aerospace, automotive, energy, and so on.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsDoped and undoped LGT single crystals were grown by Czochralski method. Growth habits of those crystals were investigated by use of seeds alongthe direction of three main physical axes X, Y and Z.ResultsResultsResultsResultsThe 2 inch undoped boules grown along Z-axis were very easier, in the terms of growth process control, than growth along X-axis and Y-axis. Thegrowth rate of boules grown along Z-axis were faster, were twice lager than the boules grown along Y-axis. The similar situation was occurred for thedoped crystals. While growth habits of the doped crystals became stronger as increasing of doping content. When 1.5 mol% MoO3 doped in LGTcrystal, the growth habit was as the same with CTGS crystal (Ca3TaGa3Si2O14, which possessed an ordered langasite structure).DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsBeginning from crystallographic structure and growth condition, the mechanisms of growth habits of doped and undoped LGT crystals were discussed,which is useful and important for mass industrial production. Conclusions obtained in this paper also can be used to guidance the growth process ofother langasite structure crystals.

Keywords:Keywords:Keywords:Keywords: langatate; langasite; piezoelectric materials; sensors


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PHASEPHASEPHASEPHASE FIELDFIELDFIELDFIELD SIMULATIONSIMULATIONSIMULATIONSIMULATIONONONONONTHETHETHETHE NONLINEARNONLINEARNONLINEARNONLINEAR FRACTUREFRACTUREFRACTUREFRACTURE OFOFOFOFFERROELECTRICFERROELECTRICFERROELECTRICFERROELECTRIC

MATERIALSMATERIALSMATERIALSMATERIALS

Hong-liang GU, Jie WANG*Department of Engineering Mechanics, School of Aeronautics & Astronautics

Zhejiang University, Hangzhou, Zhejiang 310027, China

* Tel: +86-571-87953110, Fax: +86-571-87953110, E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveFerroelectric material has received considerable attention in industry and academia due to its wide application for actuators, sensors and storage devices.Ferroelectric material often possesses defects, such as notches and voids. It is also brittle and susceptible to cracking at all scales ranging from electricdomains to devices. Under mechanical and electrical loadings, the intensified stresses and electric fields in the vicinity of notches or voids may causepolarization switching in ferroelectric materials. Due to the polarization switching, the linear piezoelectric fracture mechanics cannot predict thenonlinear fracture behavior of ferroelectrics under mechanical and electrical loadings. So it is necessary to investigate the polarization switching and thenonlinear behavior of ferroelectrics.StatementStatementStatementStatement ofofofof MethodsMethodsMethodsMethodsIn order to investigate the polarization switching and the nonlinear behavior of ferroelectrics, a three-dimensional phase field model for ferroelectricmaterials is developed based on the time-dependent Ginzburg-Landau equation (TDGL) which is solved by a Non-linear Finite Element Method. In thephase field model, the polarization is regarded as an order parameter which can change its orientation and magnitude under the external mechanical andelectrical loadings.The developed phase field model is employed to investigate the polarization switching and nonlinear behavior of a ferroelectric single crystal with anelliptical crack subjected to mechanical and electrical loadings.ResultsResultsResultsResultsIn the present work, a 3D PbTiO3 ferroelectric single crystal plate is studied in the simulation, the influence of two kinds of electrical boundaryconditions of crack on the polarization switching around the crack and the hysteresis loop of the materials are investigated. In order to model the twokinds of electrical boundary conditions, we assume that the permeable crack’s normalized dielectric constant is 1500 and the impermeable crack’snormalized dielectric constant is 0.0015.First, polarization switching in the vicinity of the crack tip induced by pure tension loading is simulated.We set all the polarization in the horizontal direction as the initial conditions, a normalized uniform tensile stress is then applied in the vertical directionto start the evolution process. For the permeable crack, the polarization switching starts from the 45°direction of the crack line. When the time stepsincrease, the switching zone becomes larger and finally reaches a steady state. For the impermeable crack, the polarization switching also starts fromthe 45°direction of the crack line which is the same with the permeable crack, while after about 50 time steps, the switching zone becomes differentfrom the permeable crack and finally reach a more complex switching zone than the permeable crack.Second, the hysteresis loops of the materials under different electrical boundary conditions of the crack are investigated. For both permeable crack andimpermeable crack, the evolution starts from a random field with very small magnitudes. For the permeable crack, it is easy to form single domainunder a smaller vertical voltage, while it is need a bigger inverse voltage to form inverse single domain. For the impermeable crack, it forms a morecomplex domain under a saturation voltage and need a smaller inverse voltage to form an inverse electric domain.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsWe employ the method of phase field simulation to investigate the influence of different electrical boundary conditions of the crack on polarizationswitching and the nonlinear behavior of ferroelectrics. It is found that the different electrical boundary conditions of the crack have a significantinfluence on the switching behavior of polarization, the impermeable crack induces a more complex domain switching process than the permeablecrack. Meanwhile, the different electrical boundary conditions of the crack also have a significant influence on the hysteresis loop of the materials, thepermeable crack induces not only a bigger saturation field but also a bigger coercive electric field, while it needs a bigger inverse voltage to form aninverse single domain compared with the impermeable crack.

Keywords:Keywords:Keywords:Keywords: ferroelectrics; electrical boundary condition; non-linear finite element method; hysteresis loopsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was financially supported by the Nature Science Foundation of China under Grants (11002123, 11090333) andZhejiang Provincial Natural Science Foundation under Grant R6110115.


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COMPOSITECOMPOSITECOMPOSITECOMPOSITE STRUCTURESTRUCTURESTRUCTURESTRUCTURE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC ENERGYENERGYENERGYENERGYHARVESTERHARVESTERHARVESTERHARVESTER USINGUSINGUSINGUSING SINGLESINGLESINGLESINGLE

CRYSTALCRYSTALCRYSTALCRYSTAL0.71Pb(Mg0.71Pb(Mg0.71Pb(Mg0.71Pb(Mg1/31/31/31/3NbNbNbNb2/32/32/32/3)O)O)O)O3333-0.29PbTiO-0.29PbTiO-0.29PbTiO-0.29PbTiO3333

Chun-Dong Xu1,2, Zhu Liang1,2, Bo Ren 1, Xiang-Yong Zhao1, Hao-Su Luo1*1Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, China

2Graduate School of the Chinese Academy of Sciences, Beijing 100049, China

* Corresponding author, E-mail: [email protected] ; Tel.: 021-69987759

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUsing piezoelectric materials to harvest ambient vibrating energy has been very a very hot topic during past two decades. Piezoelectric energy harvesterhas higher energy density, better electromechanical coupling and conveniently integrates with micro-electromechanical systems (MEMS) andintegrated circuit (IC) technologies, comparing with electrostatic and electromagnetic vibration energy harvesters. Unique merits make it promising forself-power devices, such as wireless sensor dots, autonomous energy-scavenging sensors and other low power electronics with the applications rangingfrom biomedical to homeland security.In the previous studies, PZT ceramics, piezoelectric polymer polyvinylidene fluoride (PVDF) and copolymers, piezoelectric composites materials andZnO nano-wires were commonly applied on piezoelectric energy harvesting. Recently, relaxor piezoelectric single crystal material(1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT or PMNT) has attracted continuous attention for designing and fabricating high-efficiency piezoelectrictransducers, due to its well-known ultrahigh electromechanical response (d33 and k33 could reach as high as 2500 pC/N and 0.94, respectively).However, the applications of this material in piezoelectric energy harvesting haven’t attracted sufficient attentions.On the other hand, excitation frequencies of the ambient vibration sources are normally below 300 Hz according to previous statistics. Unfortunately,maximum powers obtained at resonance frequencies below 300 Hz would be problematic for micro-scale vibration energy harvesters. Cantileverconfiguration consisting of a piezoelectric beam and a proof mass is a reasonable choice to lower resonance frequency for the piezoelectric energyharvesters. However, mechanical stress in piezoelectric materials along the cantilever beam is non-uniform during bending vibration. Stress graduallyincreases from the base to the tip along the length direction of the cantilever beam, which limits the transduction capacity of piezoelectric materialsnearby the tip of the cantilever beam in vibration energy harvesting. In 1991, E. Newnham presented a high performance piezoelectric transducernamed cymbal, then Kim introduced this structure into energy harvesting in 2004. Cymbal energy harvesters mainly work in the ⟨3-1⟩ excitation modefor rectangle piezoelectric transducers. The mechanical stress generated in piezoelectric materials is uniformly distributing, and is also amplified by thisspecial configuration of the structure, so the transduction capacity of piezoelectric materials can be fully developed. Nevertheless, high resonancefrequency is a main drawback for cymbal, and it is a challenge to lower the resonance frequency below 300 Hz.Here, we introduce a high performance piezoelectric energy harvester named CANDLE (CANtilever Driving Low frequency Energy harvester) usingthe single crystal material Pb(Mg1/3Nb2/3)O3-0.29PbTiO3. The CANDLE consists of one cantilever beam, two PMNT-stainless steel cymbals and analuminum alloy frame. The composite structure piezoelectric energy harvesting not only lowered resonance frequency of cymbal dramaticlly but alsoincreased output power immensely compared with previous resultsStatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA high-quality 0.71PMN-0.29PT single crystal ingot was grown directly from their melt by the modified Bridgman technique in our laboratory, andthen diced to give〈001〉oriented plates with dimensions of 25 mm length, 5 mm width, and 1 mm thickness. The silver electrodes were painted on theplates and fired at 700°C for 30 min. Then, the as-prepared plates were polarized in silicon oil along their thickness directions under an electric voltageof 1 kV for 15 min at 120°C with half of the voltage in the cooling run. The d31 piezoelectric coefficient of the polarized PMNT crystal plates wasmeasured to be -650 pCN-1 by an Agilent 4294A impedance analyzer according to the IEEE standard.The polarized plates were sandwiched between two protruded rectangular stainless steel (SUS 304) caps along the thickness directions usingsilver-loaded epoxy (Applied Products E-Solder 3021) to form the cymbal-type piezoelectric PMNT single crystal-stainless steel transducer. A normalcantilever beam was fabricated by a beryllium copper (C17200) slice with dimensions of 35 mm length, 5 mm width, and 0.5 mm thickness. The twoprotruded rectangular stainless steel caps, each of 25 mm total length, 2.5 mm top-flange length, and 11mm bottom-flange length, were made bydie-punching a stainless steel sheet with thickness of 0.3 mm and the same width as the PMNT plates. One cantilever beam and two PMNT-stainlesssteel cymbal transducers were assembled and clamped in an aluminium alloy frame to form a composite structure piezoelectric energyharvester-CANDLE. Some insulated plastics were filled between the cymbals, cantilever, and aluminium alloy frame to prevent electrical connection.ResultsResultsResultsResultscompared with the traditional cymbal device, the resonance frequency of CANDLE is only 102 Hz with 4.2 g proof mass, while the maximum poweroutput is much higher (3.7 mW at 102 Hz to 0.77 mW above 1000 Hz). It is necessary to emphasize that all the characteristics measured above are justproperties of one PMNT-stainless steel cymbal in CANDLE which consists of two cymbal transducers.The increment of output power decreased when proof mass increased to a large enough value. This phenomenon may be caused by that the fringe of thePMNT-stainless steel cymbal transducer and aluminum alloy frame confine transverse displacement of the cantilever beam when vibration acceleration


app:ds:prevenient

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app:ds:immensely

app:ds:stainless%20steel





app:ds:aluminium%20alloy

app:ds:aluminium%20alloy


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or proof mass are large enough. This property gives the special structure self-protection characteristic that could avoid the stress in the piezoelectricmaterials exceeding its endurance.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn conclusion, a vibration energy harvester CANDLE constituted by cantilever and cymbal structures using piezoelectric single crystal0.71Pb(Mg1/3Nb2/3)O3-0.29PbTiO3 has been designed and fabricated. A new method to study energy harvesting by compositing different piezoelectrictransducer structures is presented. The electrical properties under different proof masses, excitation frequencies and load resistances are studiedpreliminarily. Experiment results show that CANDLE using PMNT single crystal material can lower resonance frequency and increase output powerdramatically. Under the acceleration excitation of 3.2g, the device with 4.2 g proof mass can generate a peak voltage of 38 V and a maximum power of3.7 mW at 102 Hz with a matching load resistance of 251 kΩ.

Keywords:Keywords:Keywords:Keywords: energy harvesting; piezoelectric; single crystalAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was financially supported by the Ministry of Science and Technology of China through 973 Program (No.2009CB623305) and National Key Technology R&D Program (No. 2010BAK69B26), the Natural Science Foundation of China (Nos. 60837003,61001041 and 11090332), Science and Technology Commission of Shanghai Municipality (Nos. 10520712700, 10JC1415900 and 10dz0583400), theInnovation Fund of Shanghai Institute of Ceramics (Nos. O99ZC4140G and O99ZC1110G), Shanghai Rising-Star Program (No. 11QA1407500), andOpen Project from Shanghai Institute of Technical Physics, CAS (No. IIMDKFJJ-11-08).

app:ds:endurance


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PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATIONOFOFOFOFLOVELOVELOVELOVEWAVESWAVESWAVESWAVES ININININAAAATHINTHINTHINTHIN FUNCTIONALLYFUNCTIONALLYFUNCTIONALLYFUNCTIONALLYGRADEDGRADEDGRADEDGRADED PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC

LAYERLAYERLAYERLAYER IMPERFECTLYIMPERFECTLYIMPERFECTLYIMPERFECTLYBONDEDBONDEDBONDEDBONDEDTOTOTOTOAAAA PIEZOMAGNETICPIEZOMAGNETICPIEZOMAGNETICPIEZOMAGNETIC SUBSTRATESUBSTRATESUBSTRATESUBSTRATE

Dong YE1, Li-li YUAN1*, Jian-ke DU2, Ting-feng MA2

1School of Architectural, Civil Engineering and Environment, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211

2School of Mechanical Engineering and Mechanics, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveMagnetoelectric composite materials consisting of a piezoelectric phase and a piezomagnetic phase have magneto-electric effect that is not present insingle piezoelectric or piezomagnetic phase. The thin film material structures are more suitable for manufacturing the surface acoustic wave (SAW)devices or bulk acoustic wave (BAW) devices due to higher frequency. Hence, it has many potential applications in resonators, sensors, and delay lines,etc. The functionally graded materials (FGM) are widely used in many fields and can be used in SAW devices in order to improve the durability and theefficiency of the devices. As a result, there are many studies have been carried out on wave propagation behavior and characteristic in FGM. In reality,the thin layer would not be perfectly coated on the substrate due to various reasons such as damage, aging of adhesive layers, microcracks, cavities anddiffusion impurity, etc. For this reason, it is of practical significance to take the possible interface damages into consideration in the designs andapplications of SAW sensors. In this paper, we study the propagation of Love waves in a functionally graded piezoelectric layer imperfectly bonded toa piezomagnetic substrate. The linear shear-lag model is used to simulate the imperfection of bonding behavior at the interface. The classical transfermatrix method is applied to solve coupling wave equations. The properties of Love waves are studied and discussed in detail.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on the three-dimensional linear magneto-electro-elastic theory, the coupling wave equations are derived from mathematical models and solvedwith consideration of imperfectly bond. The classical transfer matrix method is applied to solve coupling wave equations considered bothmagneto-electrically open and shorted cases. The imperfect interface is described by the so-called shear-lag model that allows the displacement to bediscontinuous across the interface. The dispersion relations are plotted and numerical results showed that the influence of the interface bond parameterand the gradient factor about material constants on the dispersion characteristics is evident. The analytical method and the results can be useful for thedesign of acoustic surface wave devices based on the piezoelectric and piezomagnetic materials.ResultsResultsResultsResultsThe phase velocity versus the wave number can be obtained by the dispersive relation using Matlab software. From the results we can find that theeffects of interface bond parameter and the gradient factor about material constants on the properties of Love waves are remarkable. It can be seen thatthe phase velocity decrease with the non-dimensional wave number and increase with the graded factor when the bond is perfect, the relationshipbetween phase velocity and wave number is nonlinear, the dispersive curve is monotonous. When the bond is not perfect, the curve is non-monotonic,the phase velocity decrease with wave number initiate, then it increase with wave number till it is a linear. However, no matter the bond is perfectly ornot, the trend of different dispersion curve is the same: the phase velocity decreases with the interface bond parameter.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsAn analytical approach is taken to investigate Love waves in a layered functionally graded piezoelectric/ piezomagnetic structures, where a thinfunctionally graded piezoelectric layer was bonded imperfectly to a semi-infinite piezomagnetic substrate. The solutions of dispersion relations areobtained with magneto-electrically open or shorted conditions by analytical method. The effects of the interface bond parameter and the gradient factorabout material constants on the phase velocity are presented and discussed in detail. From the results, it can be seen that the phase velocity decreasewith the interface bond parameter and increase with the graded factor. Furthermore, when the bond is not perfect, we can find that the phase velocitydecreases with wave number at the very start, then increase till to a linear.

KeywordsKeywordsKeywordsKeywords: Love waves; layered structures; functionally graded material; imperfect interfaceAcknowledgementsAcknowledgementsAcknowledgementsAcknowledgements: The authors gratefully acknowledge the supports of the National Natural Science Foundation of China (Nos.11072116and 10932004), Zhejiang Provincial Science Fund for Distinguished Young Scholars (No. LR12A02001), and K.C.Wong Education Foundation, HongKong and K.C.Wong Magna Fund in Ningbo University.


app:ds:ideality

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AbstractAbstractAbstractAbstract bookbookbookbook ofofofof 2012201220122012 SymposiumSymposiumSymposiumSymposium onononon Piezoelectricity,Piezoelectricity,Piezoelectricity,Piezoelectricity, AcousticAcousticAcousticAcousticWaves,Waves,Waves,Waves, andandandand DeviceDeviceDeviceDevice ApplicationsApplicationsApplicationsApplications Nov. 23-25, 2012

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TEMPERATURETEMPERATURETEMPERATURETEMPERATURE DEPENDENCEDEPENDENCEDEPENDENCEDEPENDENCE OFOFOFOFELELELELEEEECTRO-ELASTICCTRO-ELASTICCTRO-ELASTICCTRO-ELASTIC PROPERTIESPROPERTIESPROPERTIESPROPERTIES OFOFOFOFYTTRIUMYTTRIUMYTTRIUMYTTRIUM

CALCIUMCALCIUMCALCIUMCALCIUM PXYBORATEPXYBORATEPXYBORATEPXYBORATE SINGLESINGLESINGLESINGLE CRYSTALSCRYSTALSCRYSTALSCRYSTALS

Fa-peng YU1, Xiu-lan DUAN1, Yong-gui YU1, Shun-jun ZHANG2*, Ji WANG3, Xian ZHAO1*

1State Key Laboratory of Crystal Materials and Institute of Crystal Materials, Shandong University, Jinan 250100, P.R. China2Materials Research Institute, Pennsylvania State University, University Park, PA 16802, USA

3Piezoelectric Device Laboratory, School of Engineering, Ningbo University, Ningbo 315211, P.R. China

* Corresponding author, E-mail: [email protected] and [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveHigh temperature smart technology would increase dramatically if sensors could operate at elevated temperatures. High temperature sensors forstructural control and structural health monitoring would allow the development of lightweight composite military aircraft that could operate withincreased maneuverability and fuel efficiency, and more reliability with less maintenance and downtime etc. Of all the functional materials investigatedfor high temperature sensors, piezoelectric materials attracted extensive attention, due to the merits of structural simplicity, low loss, long life, highsensitivity and reliability etc. Recently, rare-earth calcium oxyborate crystals with monoclinic phase were found to have no phase transition prior to themelting point (~1500 ° C) and relatively large effective piezoelectric coefficients (2~3 times that of quartz), showing the potential use for hightemperature sensors. In this work, crystal growth of yttrium calcium oxyborate (YCa4O(BO3)3, YCOB) were presented and the temperaturedependence of electro-elastic properties was discussed, for high temperature piezoelectric sensor explorations.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsSingle crystals of YCOB were grown by the Czochralski technique. The polycrystalline of YCOB, prepared by solid state method, were heated by a 2kHz low radio-frequency furnace (TDL-F40 single crystal growth furnace) in an iridium crucible with 70 mm in diameter and 50 mm in height. Thetemperature was precisely controlled by using an EU-ROTHERM 818 controller/programmer during crystal growth process. Crystal quality waselevated by using High Resolution X-Ray Diffractometor (HRXRD, Bruker AXS, D5005HR), while for the electro-elastic property investigation, thecapacitance and resonance/anti-resonance frequencies were measured by Agilent 4294A Precision Impedance Analyzer.ResultsResultsResultsResultsLarge single crystal of YCOB with dimension of 25×40 mm3 was grown by Czochralski method. The resistivity anisotropy was investigated atelevated temperature and the values were found to be one and three orders higher than that of GaPO3 and langasite crystals, respectively. Highresolution X-Ray diffractometer measurement show that the as-grown YCOB possess narrow half width of diffraction peak, being on the order of <30”,indicating high perfection of crystal lattice. Resonance frequency, electromechanical coupling factors, elastic compliance and piezoelectric straincoefficients as a function of temperature were studied from 20 to 950°C. Among the investigated crystal cuts, the (ZXw) 33º-cut was found to possesslarge first order temperature frequency coefficient (-91ppm/ ° C), comparable to that of quartz with (XYl) 5.3 ° -cut (~92 ppm/ ° C). The elasticcompliances s33 and s55 were observed to show relatively large first order temperature coefficient, being on the order of -94ppm/°C, and changedlinearly with increasing temperature, while the elastic compliance s11 exhibited relatively low temperature coefficient, being -43ppm/°C. Moreover, theeffective electromechanical coupling factor and piezoelectric strain coefficient of k26 (19%) and d26 (7.9 pC/N) were found to be temperatureindependent. Of particularly significant that, the (ZXw) 30°-cuts not only possess the maximum effective k26 and d26 values, but also the temperatureindependence of electromechanical properties, indicating the potential use for high temperature piezoelectric sensors.

Figure 1. As-grown YCOB single crystal

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsYttrium calcium oxyborate crystals (YCOB) are newly developed high temperature piezoelectric materials. The high electrical resistivity, largepiezoelectric coefficient together with relatively high stability of electromechanical properties at elevated temperatures, makes YCOB a good candidatefor high temperature sensing.

Keywords:Keywords:Keywords:Keywords: piezoelectric properties; single crystal; temperature dependenceAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 91022034) and a grant from theImpact and Safety of Coastal Engineering Initiative, a COE Program of Zhejiang Provincial Government at Ningbo University (Grant No.ZJ1111).




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MODEMODEMODEMODE COUPLINGCOUPLINGCOUPLINGCOUPLING ININININ PIMNTPIMNTPIMNTPIMNT SINGLE-CRYSTALSINGLE-CRYSTALSINGLE-CRYSTALSINGLE-CRYSTALRECTANGULARRECTANGULARRECTANGULARRECTANGULAR BEAMSBEAMSBEAMSBEAMSANDANDANDAND ITSITSITSITS

APPLICATIONAPPLICATIONAPPLICATIONAPPLICATION ININININ ULTRASONICULTRASONICULTRASONICULTRASONIC LINEARLINEARLINEARLINEARARRAYSARRAYSARRAYSARRAYS

Wei WANG1,2*, Qin-wen YUE1,2, Xiang-yong ZHAO1, Hao-su LUO1

1Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, China2Graduate School of the Chinese Academy of Sciences, Beijing 100049, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveRecently, much attention has been paid to the relaxor ferroelectric single crystals for their ultrahigh piezoelectric properties. High quality and large sizePb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-PT) single crystals has been grown well by the modified Bridgman technique, and can meet the demands indifferent ultrasonic transducer applications gradually, especially in medical ultrasonic transducers applications. However, relative low phase transitiontemperature and conceive field of PMN-PT are limitations to their long term reliability. Based on this, we have grown high Cure temperature and largercoercive field ternary Pb(In1/2Nb1/2)O3- Pb(Mg1/3Nb2/3)O3-PbTiO3 (PIN-PMN-PT) single crystals, while maintain comparable piezoelectricproperties with PMN-PT. For medical ultrasonic linear array and phased array applications, the piezoelectric elements are rectangular beams. Theresonance mode of the piezoelectric element is greatly determined by the width-to-height ratio G (G=L/H) of the rectangular beams. When the ratio isvery small, the piezoelectric element becomes a tall-and-narrow beam and operates in height-extensional mode. When the ratio is large, thepiezoelectric element becomes a thin-and-width plate and operates in thickness-extensional mode. However, when the width L is comparable withheight H, coupling of different resonance modes occurs. In order to take full advantages of the excellent piezoelectric properties of PIMNT singlecrystal in ultrasonic linear array applications, it is important to study the mode coupling in PIMNT single-crystal rectangular beams.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe studied the mode coupling in PIMNT single-crystal rectangular beams firstly. Mode coupling in PIMNT single-crystal rectangular beams isinvestigated both theoretically and experimentally. PIMNT samples with ratios increased from 0.4 to 14.0 were prepared and characterized by theresonance method. Based on the research results, we designed and fabricated three types of ultrasonic linear arrays which worked in different resonancemodes.ResultsResultsResultsResultsWhen G increases from 0.40 to 0.7, we can see that the beam mode fH1 stays quite steadily. However, due to the increase in L, the lateral moderesonance frequency fL shifts to the lower-frequency side and couples with fH1. When the sample is subsequently widened, fL decreases accordinglywhile a thickness mode fH2 emerges and becomes the dominant mode at the higher frequency range. Furthermore, with the increasing of G from 0.8 to10.0, the fundamental and harmonic of beam mode is weakening until become ignorable and the lateral mode resonance frequency shifts to frequenciesfar below the thickness mode.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe resonance characteristics of PIMNT beam agreed with the mode-coupling theory prediction. The uncoupled resonance can be get when thewidth-to-height ratio is less than 0.7 or larger than 10, which corresponding to works at uncoupled beam mode and thickness mode, respectively. Astrong mode-coupling region can be found in the range of 1.4 to 3.1, in which both beam mode and thickness mode coexist strongly and theelectromechanical coefficients are around 73% and 50%, respectively. Based on the mode-coupling effect, broadband linear array, multifrequencylinear array, and high frequency linear array were designed and fabricated.

Keywords:Keywords:Keywords:Keywords: mode coupling; relaxor ferroelectric single crystals; PIMNT; ultrasonic linear array



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THEORYTHEORYTHEORYTHEORYONONONONTHETHETHETHE LASERLASERLASERLASER EXCITEDEXCITEDEXCITEDEXCITEDWAVEWAVEWAVEWAVE PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININAAAA SINGLESINGLESINGLESINGLE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC

PLATEPLATEPLATEPLATE UNDERUNDERUNDERUNDERAAAA BIASBIASBIASBIAS ELECTRICELECTRICELECTRICELECTRIC FIELDFIELDFIELDFIELD

Gen CHEN1, Yong-dong PAN2*, Zheng ZHONG2

1 Institute of Acoustics, Tongji University, Shanghai 2000922 School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092

* Corresponding author, E-mail: [email protected].; Tel.: 86-021-65983797

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSince the discovery of the piezoelectric effect, piezoelectric materials are widely applied to sensors, actuators, filters and delay lines, used inmechanical engineering, electric engineering, and some other industrial fields. However, with the rapid development of the technology in recent years,the demand for the smart or intelligent devices grows as well. A kind of the typical smart devices is the one with the function of active controlling by anexternal field. For the convenience of the industrial manufacturing, the devices made of piezoelectric material are often designed to be layeredstructures. Therefore, it is very important to understand the physical nature of the active controlling for layered structures. In this paper, the laserexcited wave propagation in a single piezoelectric plate under a bias electric field is studied theoretically.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe wave propagation in a single piezoelectric plate under a bias electric field is treated as the problem that the waves propagate in a singlepiezoelectric plate with initial stress and electric displacement, and then the state vector approach is used to derive the differential equations for thepiezoelectric plate under a bias electric field. The laser is modeled as a transient force at the boundary. The softness matrix method is further used tosolve the differential equations to avoid the numerical instability when the product of thickness and frequency increases.ResultsResultsResultsResultsBy solving the differential equation, both the dispersion curves and surface displacement of the epicenter of the single piezoelectric plate under the laserablation excitation with bias electric field are obtained. It is found that the wave propagation in the piezoelectric is influenced by the bias electric field.The numerical calculation shows that along the polarization direction, the velocity of the quasi-longitudinal wave in the piezoelectric plate with positivebias electric field is larger than that without any electric field, which is just an inversed situation for the negative configuration.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn addition, the behavior of wave propagation in the piezoelectric plate is varied by loading different bias electric field. By choosing a certain biaselectric field, the velocity of the acoustic wave in the piezoelectric plate is determined respectively, which will make the possibility of activelycontrolling the acoustic wave. The theoretical findings will provide the basis for the further experimental investigation.

Keywords:Keywords:Keywords:Keywords: piezoelectric plate; laser ultrasonic; bias field; active controlAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10834009, 11090333) and was alsosupported by the Fundamental Research Funds for the Central Universities, Tongji University (0270219037).

mailto:[email protected].


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FASTFASTFASTFASTALGORITHMALGORITHMALGORITHMALGORITHMFORFORFORFORTHETHETHETHEMETHODMETHODMETHODMETHODOFOFOFOFFUNDAMENTALFUNDAMENTALFUNDAMENTALFUNDAMENTALSOLUTIONSOLUTIONSOLUTIONSOLUTION SUBJECTEDSUBJECTEDSUBJECTEDSUBJECTED TOTOTOTO

MULTI-SYMMETRYMULTI-SYMMETRYMULTI-SYMMETRYMULTI-SYMMETRYPROBLEMSPROBLEMSPROBLEMSPROBLEMS

Li-na WU1, Hai-e WEI1, Quan JIANG1,2*

1College of Science, Nantong University, Nantong, 2260192College of Civil Engineering, Nantong University, Nantong, 226019


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe method of fundamental solution (MFS) is a true boundary type meshless method for the boundary value problems. This meshless method ofintegral free is a powerful tool for the general elliptical PDEs in many computational fields. MFS is related to the combination of the fundamentalsolutions, which does not need integral on the boundary.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on the idea of image technique, the fundamental solutions are reconstructed for the symmetrical problems to reduce the computational cost. Thebasic equations of a type of ellaptical PDEs and the coordinate transformation technique are provided.ResultsResultsResultsResultsFrom the numerical experiments, it is seen that the results in this paper have good accuracy and high efficiency. MFS with coordinate transformationtechnique can solve more elliptical PDES compared with the classic field of harmonic and biharmonic equations. In particular, the programming, datepreparing and the linear equations for computing can be greatly reduced by using the reconstructed fundamental solutions with image technique.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsMFS with coordinate transformation and image technique is introduced to the numerical solution of a class of the elliptical PDEs in this paper. Thecoordinate transformation is used for converting the general PDEs into the harmonic function. For the symmetrical problems, the improvedfundamental solutions are reconstructed by using the special boundary conditions on the symmetrical axises. With the help of these reconstructedfundamental solutions, the efficiency of computing is greatly improved. The method in this paper has the merit of integral free, and only the algebraiccalculus is needed.

Keywords:Keywords:Keywords:Keywords: method of fundamental solution; image technique; coordinate transformationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10902055 and 11172252).



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ELECTRICALELECTRICALELECTRICALELECTRICALANDANDANDAND STRESSSTRESSSTRESSSTRESS FIELDSFIELDSFIELDSFIELDS OFOFOFOFTHETHETHETHE SURFACESURFACESURFACESURFACE ELECTRODESELECTRODESELECTRODESELECTRODES ONONONONTHETHETHETHE

ELECTROSTRICTIVEELECTROSTRICTIVEELECTROSTRICTIVEELECTROSTRICTIVEMATERIALMATERIALMATERIALMATERIAL

Hai-e WEI1, Quan JIANG1,2*, Li-na WU1

1College of Science, Nantong University, Nantong, 2260192College of Civil Engineering, Nantong University, Nantong, 226019


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAs a necessary carrier of electric loading, electrodes are usually used in smart structures and devices, which are in general made of electrostrictivematerials. No work can be found for the cases of electrodes on the surface of an electrostrictive material. It is therefore the purpose of this work to studythe field singularities of surface electrodes.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe basic equations based on the work of Stratton, Landau and Lifshitz. The general solution for the potential functions of electric and stress fields aregiven for two-dimensional problem. The field singularities of electrodes on the surface of a half-infinite electrostrictive solid are studied with thecomplex variable method.ResultsResultsResultsResultsThis work has presented the general solution for the electroelastic fields of surface electrodes of a half-infinite electrostrictive material. It is found thateven at the low level of applied electric loading, considerable high stresses will be induced around the tip of electrodes.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIt is concluded that the stress fields in an electrostrictive material can be finally expressed by the electrical potential. Thus, once the electrical potentialis obtained, one can easily determine the electroelastic fields.

Keywords:Keywords:Keywords:Keywords: electrostriction; surface electrode; singular stress fieldAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10902055 and 11172252).



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THEORYTHEORYTHEORYTHEORYONONONONTHETHETHETHEAIR-COUPLEAIR-COUPLEAIR-COUPLEAIR-COUPLEWAVEWAVEWAVEWAVE PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININ LAYEREDLAYEREDLAYEREDLAYEREDCOMPOSITECOMPOSITECOMPOSITECOMPOSITE

MATERIALSMATERIALSMATERIALSMATERIALSWITHWITHWITHWITHLAMINATELAMINATELAMINATELAMINATE DEFECTDEFECTDEFECTDEFECT

Song LING1, Yong-dong PAN2*, Kao-shan DAI31Institute of Acoustic, Tongji University, Shanghai 200092

2School of Aerospace and Applied Mechanics, Tongji University, Shanghai 2000923School of Civil Engineering, Tongji University, Shanghai 200092


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveLaminated composite materials such as glass fiber laminate (GLARE), carbon fiber reinforced plastics (CFRP) and honeycombs are extensively used inmodern aerospace, civil engineering and manufacturing & industry. Due to the safety and reliability requirements, these materials must be evaluatedand characterized during manufacturing process and maintenance. Currently, laminated composite materials are mostly tested by the immersiveultrasonic technique. However, this technique is inconvenient and time consuming for industrial applications; it cannot be applied to materials such ashoneycombs or hot structures that can neither be immersed nor touched. Therefore, effective non-contact sensing methods should be developed.Although lasers can be sued for charactering material properties without contacting the measuring object, they are costly and complex experimentalsetup hinder on-site industrial applications of laser sensors. Air-coupled techniques show great potential for composite material characterization. So far,the air-coupled sensing limited to qualitative detection. e. g. determining whether or not there is a defect. The objective of the investigation is toimprove this technique the quantitative assessment of laminated composite materials.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, the spring model for the layered composite materials was established to stimulate wave propagation in the defect along its interface. Theinterface was introduced as a zero thickness ‘material layer’, which has specified material constants that govern stiffness. Since the interfacial springstiffness can be evaluated through ultrasonic reflection and transmission analysis, the proposed model can be used to determine the quality of disbandarea between two dissimilitude layers, which is directly related to the quality of adhesive interface. The numerical instability in the standard transfermatrix method was resolved. A stiffness matrix-based numerical method was applied for quantifying the reflection and transmission coefficients of theplane wave.ResultsResultsResultsResultsA numerical model was developed to simulate the acoustic pressure on the layered composite materials with defect being emitted by air-coupledtransducers. To study these properties to a large domain, the model assumes that the attenuation is proportional to the frequency. The coefficientspectrum of transmission and reflection with regard to frequency domain was obtained. Three types of interfaces that describe the adhesive conditionsof laminate materials, which include rigid connection, feeble connection and slip connection. These different models were computed and compared inthis study.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsAir-coupled wave propagation in layered composite materials with laminate defect has been investigated. The boundary conditions that model interfaceare introduced for the use of stiffness matrix of the multi-layers. Thanks to the stability of the stiffness matrix method, the solutions of the transmissionand reflection are numerically stable and efficient. This work has shown that the spring models are well adapted to control the quality and integrity ofcomplex composite structures.

Keywords:Keywords:Keywords:Keywords: spring model; stiffness matrix; laminate composite materials; air-coupledAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No.10834009, 11090333) and theFundamental Research Funds for the Central Universities, Tongji University (0270219037).



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INVERSIONINVERSIONINVERSIONINVERSIONOFOFOFOFSHEARSHEARSHEARSHEARVELOCITYVELOCITYVELOCITYVELOCITYPROFILEPROFILEPROFILEPROFILE ININININAAAA CASEDCASEDCASEDCASED BOREHOLEBOREHOLEBOREHOLEBOREHOLE

Ming-ming MA*, Hao CHEN, Xiao HE, Xiu-ming WANGState Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSonic logging through casing in petroleum industry is significant and widely applied. In cased wells, the formation near the borehole wall is oftendamaged. Thus the formation shear velocity show radial variations. In this paper, we will develop an inversion method for the shear velocity profilefrom flexural dispersion data.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe model in this study is constructed by a fluid-filled well-bonded cased borehole with a radially layered formation outside. The thickness and shearvelocity of each layer are different from that of others, and can’t be inverted from flexural dispersion data easily, because the number of them isexcessive.In order to reduce the number of inverted parameters, we use an exponential profile controlled by three parameters to express the radial variations of theformation shear velocity approximately. The objective function for inverting the three parameters based on the perturbation method is established. Thevalues of the parameters that minimize the function are estimated from flexural dispersion data using Gauss-Newton and VFSA method, respectively,hence the radial variations are obtained.ResultsResultsResultsResultsUsing flexural dispersion data over a wide frequency bandwidth helps inversion. Great error of the result will come out when the casing shear wavevelocity is inaccurate. In our problem, compared with VFSA method, Gauss-Newton method has the same calculation accuracy, and is more efficient,but its convergence is strongly dependent on the choice of the initial values.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsRadial variations of the formation shear velocity can be obtained by minimizing the objective function. It is very important to obtain casing shearvelocity accurately before inverting the three parameters. A bad result will be obtained if the initial values are not properly selected when usingGauss-Newton method.

Keywords:Keywords:Keywords:Keywords: sonic logging; cased well; shear velocityAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Grant No. 11134011 and No. 41204099)and the Project of Innovation and Prospection in Institute of Acoustics, Chinese Academy of Sciences.



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THETHETHETHEANALYTICALANALYTICALANALYTICALANALYTICALSOLUTIONSOLUTIONSOLUTIONSOLUTIONANDANDANDANDNUMERICALNUMERICALNUMERICALNUMERICALSIMULATIONSIMULATIONSIMULATIONSIMULATIONOFOFOFOFTHETHETHETHE P-SVP-SVP-SVP-SVWAVEWAVEWAVEWAVE

PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININ THETHETHETHE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC LAMINATELAMINATELAMINATELAMINATE

Lei LIU, Yong-dong PAN*, Zheng ZHONGSchool of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveRecently, the active control of the wave propagation in the medium attracted a lot of attentions all around the world. The material with piezoelectricityis named piezoelectric material, and plays a key role in the active control of the wave propagation. It is found that the piezoelectricity has changed theconstitutive equation of the material and has made the materials smart. Specially, the piezoelectric laminate was mostly used in the manipulation ofwave propagation, and various acoustic devices, for instance, the transducer and etc. Although the propagation of P-SV wave in the laminate has beenanalyzed, the acoustic field distribution of the piezoelectric laminate is not definitely post, and the relationship between the transmission coefficientsand the incident angle is still not enough revealed, even if the piezoelectricity is ignored. The acoustic field distribution can help people to understandthe wave propagation in the piezoelectric laminate easily. The transmission coefficients can be observed directly through the experiments, so it is ofgreat importance to study them. The electrical boundary conditions of the piezoelectric material may significantly affect the behavior of wavepropagation due to the introduction of piezoelectricity. In this paper, the P-SV wave propagation in the piezoelectric laminate is studied analytically andnumerically. The transmission coefficients with the different electrical boundary conditions will be obtained numerically by using the COMSOLsoftware, contrastively the analytical results are obtained through the softness matrix method. Considering the incident angle, the different wave modesare brought forth.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsCOMSOL is a software of solving PDE by the finite element method; it can solve the problem of multi-physics. The coupling of the acoustic field andelectric field can be simulated by COMSOL software commendably. The analytical results are gained through the softness matrix method, and used toverify the numerical results. The P-SV wave propagation in the piezoelectric laminate is revealed profoundly through the analytical solution andnumerical simulation; it can be used to help the design and production of piezoelectric device.ResultsResultsResultsResultsThe analytical model of piezoelectric laminate is established, and the P-SV wave propagation problem is studied. The model is introduced into theCOMSOL, and the acoustic field and electric field with open/closed electric boundary conditions are simulated. The transmission coefficients spectrumwith variational incident angle is obtained analytically and numerically. The analytical and numerical results agree quite well for the piezoelectricityignored plate and the electric circuit open or closed piezoelectric plate.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe piezoelectricity increases the acoustic speed, and it may be explained that the piezoelectricity make the material compacted, just as the prestress.The electrical boundary condition affects the wave propagation slightly, only in some special wave pattern. The critical incident angles are also raiseddue to the piezoelectricity.

Keywords:Keywords:Keywords:Keywords: piezoelectricity; laminate; P-SV wave; simulation; transmission coefficientAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10834009, 11090333).


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THREE-DIMENSIONALTHREE-DIMENSIONALTHREE-DIMENSIONALTHREE-DIMENSIONALVIBRATIONVIBRATIONVIBRATIONVIBRATIONANALYSISANALYSISANALYSISANALYSIS OFOFOFOF SPLITSPLITSPLITSPLIT ELECTRODEELECTRODEELECTRODEELECTRODEVIBRATORVIBRATORVIBRATORVIBRATORUSINGUSINGUSINGUSING

FINITEFINITEFINITEFINITE ELEMENTELEMENTELEMENTELEMENTMETHODMETHODMETHODMETHOD

Lin FU*, Dong WANG, Xiu-ming WANGState Key Laboratory of Acoustics, Institute of Acoustics, Chinese Academy of Sciences, Beijing, 100190


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe piezoelectric ceramic thin strip is a kind of longitudinal extension vibrator. When the vibrator’s electrode is split, it turns to be a high frequencyresonator. Few studied on the split electrode vibrator. In order to make good use of this kind of vibrator, it is necessary to know the vibration featuresand its relationships with the split electrode area and numbers.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsFor the cases that are difficult to get an analytical solution, the finite element method with three-dimensional theory of piezoelectricity can efficientlysolve such problems. ANSYS is used to obtain numerical results. The curves of frequency to length and width are plotted. The effect of the electrodearea and the number of electrodes to the frequency and admittance which relates to the vibrator’s sensitivity, the end displacement which is cared moreare all studied.ResultsResultsResultsResultsNumerical results show that the frequency decreases as the length increases, and the width has little influence. When the electrode area decreases, thefrequency increases small. The number of electrodes determines the order of resonance frequency. The way of splitting electrode can increase thevibrator’s admittance. The end displacement decreases as the electrode area decreases.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsNumerical results are in agreement with the existing theoretical result. Splitting electrode is a way to get high frequency and high sensitivity. The resultobtained in this paper can be considered in the design of high-frequency and high-performance transducer.

Keywords:Keywords:Keywords:Keywords: longitudinal extension vibration; split electrode vibrator; ANSYSAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Grant No. 11134011).



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SOLIDSOLIDSOLIDSOLID ELEMENTSELEMENTSELEMENTSELEMENTSWITHWITHWITHWITH SURFACE-BONDEDSURFACE-BONDEDSURFACE-BONDEDSURFACE-BONDED PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC PATCHPATCHPATCHPATCH

Rong-qiao XU1*, Jing YANG1, Yun WANG2

1Department of Civil Engineering, Zhejiang University, Hangzhou 3100582School of Mechanical Engineering, Hangzhou Dianzi University, Hangzhou 310018


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveDue to the outstanding electromechanical coupling property, piezoelectric materials had wide applications in smart structures, structural healthmonitoring and energy harvesting. Consequently, the investigation of interaction behaviors between the piezoelectric materials and host structuresattracted many researchers. Because of its feasibility, the finite element method also played an important role in this field. In civil engineering, thepiezoelectric materials was usually fabricated in form of patches and bonded on the surfaces of host structures. As a result, the interaction between thesurface-bonded piezoelectric patch with the host structures should be well understood to design or manufacture. Since the thickness of the piezoelectricpatches were much less than the sizes of the host structures, the existed solid elements of piezoelectric materials were not suitable because they did nottake advantage of the geometrical features of piezoelectric patches. On the other hand, the shell or beam elements of piezoelectric materials hadrotational degrees of freedom and the effect of the adhesive layer was neglected.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on the theory of piezoelectricity and variational principles, this works developed some solid elements with surface-bonded piezoelectric patch, inwhich the geometrical features of the piezoelectric patches were considered as well as the effect of the adhesive layer.ResultsResultsResultsResultsSome numerical examples were given to demonstrate the present elements and the results were compared with those by conventional finite elements.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIt was shown that the presented elements could be conveniently used to model the host civil structures with surface-bonded piezoelectric patches.

Keywords:Keywords:Keywords:Keywords: finite element method; piezoelectric patch; electromechanical impedance method; piezoelectric strain gauge; energy harvestingAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by Zhejiang Provincial Natural Science Foundation of China under Grant No. LY12A02001.



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DEPTHDEPTHDEPTHDEPTH PROFILINGPROFILINGPROFILINGPROFILINGOFOFOFOFCOATINGCOATINGCOATINGCOATING BYBYBYBYLASERLASERLASERLASER ULTRASONICULTRASONICULTRASONICULTRASONICTECHNIQUETECHNIQUETECHNIQUETECHNIQUE

Xue-hang SONG1, Yong-dong PAN1*, Kao-shan DAI2, Zheng ZHONG1

1School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 2000922School of Civil Engineering, Tongji University, Shanghai 200092


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveIn aerospace and other high-tech engineering areas, coating structures are becoming more and more widely applied to eliminate thermal stress of thestructures. Accurate and nondestructive approaches are needed to characterize the coating for quality evaluation, feedback to production improvement,or testing purposes. Laser ultrasonic technology is proved to be a powerful tool with high temporal and spatial resolutions and precision for layeredmaterial assessment. Penetration of Rayleigh waves or surface acoustic waves (SAW) is associated with the Rayleigh wave frequency; in other words,the longer wavelength (or lower frequency), the deeper the wave can reach beneath the surface. Therefore, SAW spectroscopy is used to characterizethe depth-depending subsurface properties of coatings.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsUsing the reflection and transmission coefficients method developed by Kennett and his coworker (Kennett, 1974; Kennett and Kerry, 1979; Kennett,1983), the sensitivity of dispersion curves to depth-profiling parameters of coating was studied. Laser ultrasonic testing of a coating was implemented.Experimental dispersion curves were obtained by the two-dimension Fourier transform. Intelligent methods such as the artificial neural network and thegenetic algorithm were used to solve the inverse problem of coating characterization. For the genetic algorithm, the object function was establishedbased on the experimental phase velocity and theoretical phase velocity comparison.ResultsResultsResultsResultsAmong the parameters affecting dispersion curves, transverse wave velocity is proved more sensitive than longitudinal wave and density. Variousdepth-profiling coatings have different dispersion spectra. For example, when the wave travels faster within the surface layer compared the rest, there isonly one Rayleigh wave mode; and the phase velocity decreases as the frequency increases. Both the artificial neural network and the genetic algorithmwell reconstruct the depth-profiling properties of coatings in this study.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsDispersion curves are sensitive to the transverse wave velocity but they are not very sensitive to longitudinal wave velocity and density. Intelligentmethods handle the inverse problem well. The reconstructed depth-profiling material properties agree with the experimental ones. Although there arestill many challenges in solving the inverse problem reliably, intelligent method is an efficient approach to solve complex inverse problems.

Keywords:Keywords:Keywords:Keywords: coating; laser ultrasonics; inverse problem; intelligent methodsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work is supported by the National Natural Science Foundation of China (No. 10834009, 11090333) and theFundamental Research Funds for the Central Universities, Tongji University (0270219037).



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ANALYSISANALYSISANALYSISANALYSIS OFOFOFOFPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC LAMINATEDLAMINATEDLAMINATEDLAMINATED PLATESPLATESPLATESPLATES USINGUSINGUSINGUSINGTHETHETHETHE LAYERWISELAYERWISELAYERWISELAYERWISE PLATEPLATEPLATEPLATE

THEORYTHEORYTHEORYTHEORYANDANDANDANDRADIALRADIALRADIALRADIALBASISBASISBASISBASIS FUNCTIONFUNCTIONFUNCTIONFUNCTION COLLOCATIONCOLLOCATIONCOLLOCATIONCOLLOCATIONMETHODMETHODMETHODMETHOD

Yu YIN1, Lin-quan YAO2*

1School of Mathematical Science, Soochow University, Suzhou 2150062School of Urban Rail Transportation, Soochow University, Suzhou, 215006


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveRecently, the coupled mechanical and electrical properties of piezoelectric ceramics make them well suited for using as sensors and actuators in smartstructures. The direct and converse piezoelectric effects govern the interaction between the mechanical and electrical behavior of this type of material.Additionally, the fiber-reinforced laminated composite materials with the high strength-to-weight ratio find several applications, such as in theaerospace fields. The construction of a laminated composite by stacking many thin layers, including piezoelectric ceramic layer and non-piezoelectriclayer, together, makes the monitor and the automatic control possible. However, this effort requires the development of the detailed coupling relationbetween mechanic and electricity. During the research process, stress-strain fields should reflect the 3-D constitutive relationship and interfacialphenomena. As we known, the layerwise plate theory provides a good compromise for the piezoelectric laminated composite plates by introducingdiscrete layer transverse shear and normal effects into the assumed displacement field.In the last 20 years meshless methods enlarge their application field, and are today a competitive and alternative numerical method. Various approachesare proposed, namely the smooth particle hydrodynamics (SPH), the reproducing kernel particle method (RKPM), the hp-clouds method, the partitionof unity method (PU), the meshless local Petrov-Galerkin method (MLPG), the element-free Galerkin method (EFG), the meshless collocation method,the meshless weak-strong form method (NWS) and so on. Of these, the collocation method has been applied with success to some engineeringproblems because it is simple to obtain the discretized equations, computationally efficient and a truly meshless method.In this paper, a new formulation of piezoelectric laminated plates based on the linear piezoelectricity theory, the layerwise theory and radial basiscollocation method is developed to analyze the bending behavior of piezoelectric laminated plates.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe linear piezoelectricity theory focuses on the coupling between mechanical deformations and the charge equations of electrostatics. The layerwisetheory is used for the mechanical displacement field and the potential function. The equations of motion and boundary conditions are developed usingan energy principle. A meshless collocation method based on the radial basis function is used to discrete the system equations. The problem domain isdivided into the couple of 2-D surfaces and 1-D thickness lines. 2-D surfaces can be represented by scattered nodes. The approximation functions haveinterpolation property to enforce the boundary conditions directly.ResultsResultsResultsResultsSeveral kinds of piezoelectric laminated plates are computed by the proposed method. They have different geometry sizes, materials, boundaryconditions and so on. Numerical results are listed in the tables and figures of this paper by comparing with the existing results, including seriessolutions and FEM’s results.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsLaminated plates and the corresponding coupled electromechanical models are developed and described. The described laminate theory entails mixeddisplacement and electric field formulations and implements layerwise representations of the displacements and electric potential. Collocation methodis a truly meshless method and saves much cost of preprocess. The proposed approach is good in that it can reflect the laminar stress effect, produceexactly electromechanical behaviors and accommodate multiple voltage inputs or outputs.By comparing the results with series solutions and FEM’s solutions, numerical examples demonstrate the validity and precision of the proposed method.Additionally, this method can also extend to model the nonlinear behavior, vibration, buckling and active control of piezoelectric laminated plates orshells.

Keywords:Keywords:Keywords:Keywords: piezoelectric laminated plate; layerwise theory; meshless collocation method; radial basis functionAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was supported by the National Natural Science Foundation of China (No. 11172192) and the CollegePostgraduate Research and Innovation Project of Jiangsu province (No. CXZZ12_080).


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PREPARATIONPREPARATIONPREPARATIONPREPARATIONANDANDANDAND PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICANALYSISANALYSISANALYSISANALYSIS OFOFOFOFTHETHETHETHEMULTILAYERMULTILAYERMULTILAYERMULTILAYER FILMSFILMSFILMSFILMS FORFORFORFOR FBARFBARFBARFBAR

Lin SU1*, Bao-he YANG1,2, Cui-ping LI21College of Precision Instrument and Opto-Electronic Engineering, Tianjin University, Tianjin 300072, China

2Tianjin Key Laboratory of Film Electronic and Communication Devices, Tianjin University of Technology, Tianjin 300384, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe film bulk acoustic resonator (FBAR) device can meet the requirements of 3G mobile communication due to their excellent properties such as highresonant frequency (up to 10GHz), small size and high energy conversion efficiency.For a FBAR device of back-etched type or air-gap type, a support layer is usually added between the bottom electrode and the silicon substrate toenhance the mechanical strength of the device because its sandwich structure of “top electrode/piezoelectric/bottom electrode” is very thin (severalmicrons). Currently the Si3N4 film is selected as the support layer for the FBAR device because of its perfect properties such as high hardness andetching selectivity. The diamond-like carbon (DLC) film with higher hardness and better corrosion resistance compared to Si3N4 film can be depositedat low temperature, so we can expect that the substitution of DLC film for Si3N4 film as a support layer can improve the mechanical strength andIC-compatibility of the FBAR device.The preparation of high-quality piezoelectric films with high c-axis orientation and high piezoelectric coefficient is a key factor influencing theperformance of FBAR devices. Zinc oxide (ZnO) films have excellent electrical, optical and piezoelectric properties giving them wide applications aspiezoelectric films of the surface acoustic wave (SAW) devices and FBAR devices.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this research, a multilayered structure of Al/ZnO/Al/DLC for FBAR devices is proposed based on the above analysis. The preparation andcharacterization of DLC and ZnO films are investigated, and the microscopic piezoelectric properties of ZnO films are also studied in this paper. Untilnow, there are few reports about the multilayered structure of Al/ZnO/Al/DLC used for FBAR device, especially its piezoelectric propertiesmeasurement. In this research, DLC films were deposited by using electron cyclotron resonance chemical vapor deposition (ECR-CVD) system.Compared with MPCVD, ECR_MPCVD system has a microwave resonance magnetic field, so the ionization rate of reaction gas is improved greatly,and high-quality DLC films can be deposited at low temperature or even at room temperature. The microstructure and surface morphologies of the DLCfilms deposited by using ECR_CVD system at low temperature(＜100) are investigated by Fourier transform infrared spectroscopy (FTIR), Ramanspectroscopy, and atomic force microscopy (AFM).X-ray diffraction (XRD), AFM and SEM are employed to investigate the microstructure and surfacemorphology of the ZnO films prepared by using RF magnetron sputtering system. In particular, the local piezoelectric uniformity of the ZnO films withhigh c-axis orientation is tested by piezoresponse force microscopy (PFM). PFM is a scanning probe microscopy based on the theory of inversepiezoelectric effect, recoding the piezoelectric information through the deformation of the samples caused by an AC voltage applied between theconductive probe and the bottom electrode.ResultsResultsResultsResults andandandand DiscussionDiscussionDiscussionDiscussionThe DLC film with a smooth surface roughness and high sp3 content was prepared by using ECR-CVD system with the power of 1200W, the totalpressure of 1Pa, as well as the CH4 and Ar ratio of 1:9, meeting the requirements of FBAR technology and IC-compatibility.An Al electrode layer was prepared by using DC magnetron sputtering system, and then the ZnO film with high c-axis orientation was prepared at250 temperature, with total pressure of 1 Pa, the RF power of 100 W as well as the argon and oxygen gases ratio of 10:5. The sample was annealed at350 temperature in oxygen ambient for 1 hour. The results indicate that the annealing treatment can improve the performance of ZnO film.The piezoresponse magnitude and phase of the ZnO film with high c-axis orientation was measured by using PFM. The results indicate that there is alarge piezoresponse magnitude in the direction perpendicular to the surface of the film, inferring a strong piezoelectricity in this direction. A weakpiezoresponse in the direction parallel to the surface of the film also can be detected. The results also show good piezoresponse phase uniformity in thedirection perpendicular to the surface of the film, inferring that the piezoresponse is uniform.ConclusionsConclusionsConclusionsConclusionsThe DLC films deposited at low temperature(<100) have good performance and smooth surface morphology, meeting the requirements of FBARdevice technology. High c-axis oriented ZnO films can be prepared with the optimized process parameters, and the annealing treatment can improve theperformance of the ZnO films.The PFM measurements indicate that there is a large piezoresponse magnitude in the direction perpendicular to thesurface of the prepared ZnO film, and the piezoresponse is uniform.

Keywords:Keywords:Keywords:Keywords: FBAR; ZnO; PFM; piezoresponseAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work has been supported by the National Natural Science Foundation of China (No.50972105), the Key SupportingPlan Program of Tianjin (No.10ZCKFGX01200), and the Tianjin Natural Science Foundation (No. 09JCZDJC16500, 10SYSYJC27700).



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STUDYSTUDYSTUDYSTUDYONONONONAAAAHIGHHIGHHIGHHIGH SENSITIVITYSENSITIVITYSENSITIVITYSENSITIVITYTANGENTIALTANGENTIALTANGENTIALTANGENTIALPOLARIZEDPOLARIZEDPOLARIZEDPOLARIZEDACOUSTIC-PRESSUREACOUSTIC-PRESSUREACOUSTIC-PRESSUREACOUSTIC-PRESSURE

HYDROPHONEHYDROPHONEHYDROPHONEHYDROPHONE

Hu ZHANG*, Hong-juan CHEN, Qi LIScience and Technology on Underwater Acoustic Laboratory, Harbin Engineering University, Harbin 150001


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveEnhance the sensitivity of the hydrophone has a significant impact on improving its reception performance. Along the radius of the cylindrical acousticpressure hydrophone has a uniform directivity and high sensitivity along the radius, and has a simple structure, so it is widely used in various fields ofmarine development, underwater acoustic technology, and ultrasound technology, and is often used as the standard hydrophone. Denmark B & Kproduction 8104 type cylindrical acoustic pressure hydrophone is a model of them.This paper has theoretical analyzed the cylindrical piezoelectric ceramic pressure hydrophone, based on piezoelectric ceramic circular tube freevibration and cylindrical piezoelectric ceramic receiver static theoretical analysis, we can get the sensitivity of hydrophones covered with plate whosehave three different polarization models, and carries on the comparison, determine the hydrophone use tangential polarized way has the relatively highsensitivity. We has design and make a hydrophone sample, it’s working frequency band is 100Hz-20kHz,acoustic pressure sensitivity greater than-192dB, within this working frequency band, hydrophone sample sensitivity is about 10dB higher than 8104 standard hydrophone sensitivity.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe core element of cylindrical piezoelectric transducer is piezoelectric ceramic tube, there are three different polarization models: radial polarization,vertical polarization and tangential polarization. Actual transducer mechanical boundary conditions are the following three cases: tube end suffers noforce(shielding end), per unit area of the pipe end suffers a uniform pressure(exposure end),at the tube end covered with a plate(capping end).Combinethree polarization modes and three boundary conditions, there are nine kinds of open-circuit receiver voltage sensitivity in working state. In the designof the actual transducer, we generally covered plates on the two ends of the tube, thus formed a covered plate hydrophone, covered plate has a acousticpressure amplification effect, which can significantly improve the sensitivity of hydrophone. Therefore, we will use the covered plate hydrophone in thedesign of hydrophone in this paper .Compare three different polarization models sensitivities in the same size, we can find that the free field voltage sensitivity of tangential polarizedpiezoelectric ceramic tube is significantly higher than the longitudinal polarized and radial polarized piezoelectric ceramic tube, therefore we choose therelatively high sensitivity tangential polarized piezoelectric ceramic as the hydrophone sensor, the tube’s outside radius 14b = mm, wall thickness

2.5t = mm, inside radius 11.5a = mm, tube length 15l = mm, average radius 12.75r = mm.ResultsResultsResultsResultsAccording to the theoretical calculation formula ,the resonant frequency of tangential polarized tube hydrophone in air is 32.7kHz,acoustic pressuresensitivity is -178dB,actual test result is that ,resonant frequency in air is 32.4Hz,sensitivity is -190dB.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe acoustic pressure hydrophone designed in this paper using PZT-5 piezoelectric ceramic tube as vibration element, the resonant frequency in air is32.4KHz,which is basically consistent with the theoretical design, there is a certain deviation between the measured free-field open-circuit voltagesensitivity of the hydrophone and the theoretical design receiving sensitivity, the theoretical design receiving sensitivity of the hydrophone is -177.6dB,and the actual measurement hydrophone receiver sensitivity is about -190dB, there is a certain deviation with the theoretical design, the main cause ofthe deviation is the major influence of the production process of the hydrophone and cable distribution capacitor.

Keywords:Keywords:Keywords:Keywords: high sensitivity; pressure hydrophone; tangential polarizationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the Science and Technology on Underwater Acoustic Laboratory Foundation of China (No.9140C200203100C20).


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STUDYSTUDYSTUDYSTUDYONONONONAAAAHIGHHIGHHIGHHIGH SENSITIVITYSENSITIVITYSENSITIVITYSENSITIVITYANDANDANDAND STRONGSTRONGSTRONGSTRONGANTI-JAMMINGANTI-JAMMINGANTI-JAMMINGANTI-JAMMINGCO-VIBRATINGCO-VIBRATINGCO-VIBRATINGCO-VIBRATINGVECTORVECTORVECTORVECTOR

SENSORSENSORSENSORSENSOR

Hu ZHANG*, Qi LI, Hong-juan CHENScience and Technology on Underwater Acoustic Laboratory, Harbin Engineering University, Harbin 150001


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAt present, acoustic vector sensor technology is one of the focus objects of the research in the field of underwater acoustic. Among which, co-vibratingacoustic vector sensor has been rapidly applicated in underwater acoustic engineering fields because of its good low frequency directivity and higherlow frequency sensitivity and relatively small volume and weight.According to different sensitive element, co-vibrating vector sensor can be divided into piezoelectric type, moving coil type, piezoresistive type andoptical fiber type. At present, the sensitivity of piezoelectric co-vibrating acoustic vector sensor is about -215dB（0dB re 1V/µPa）, and the diameter isabout φ 150mm. But because of its special work mode, co-vibrating vector sensor is more easily to be influenced by the applicated carrier vibrationand the flow noise. Experiment show that when water fluid is quick enough to form turbulent on the surface of sensor, co-vibrating sensor is affectedmore than acoustic pressure-sensor. But, if cover rubber layer on its surface, the flow noise can be significantly decreased.This paper basis for the design theory of co-vibrating acoustic vector sensor, design and manufactured a high sensitivity and strong anti-jammingco-vibrating cylinder acoustic vector sensor, sensitivity is -195dB(re 200Hz), length is 166mm, diameter is 50mm. And this vector sensor can be fixedinstalled, eliminating the adverse effects from the suspension system of co-vibrating vector sensor.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAcoustic theory study have shown that, if the geometric dimensions of the acoustic rigid cylinder is much smaller than the acoustic wavelength, that iskL<<1(k-wavenumber; L-maximum size linear dimension). And if, the average density of the rigid cylinder is equal to the density of the water medium,the vibration velocity amplitude of cylinder is the same to the vibration velocity amplitude of the water particles of the geometric center of the cylinderin the sound field, and the phase difference tends to zero, this is the basic design theory of co-vibrating acoustic vector sensor. The lower of the averagedensity of cylinder sensor (Refers to less than the density of the water medium), the larger of the amplitude and phase of velocity ranges affected by thecylinder size, on the contrary, the higher of the average density of cylinder sensor, the smaller of the amplitude and phase of velocity ranges affected bythe cylinder size. But there is a inflection point for phase influence, when cylinder size achieve this the inflection point, phase fluctuation suddenaggravate. So, according to design theory, the designed acceleration sensor density is about 0.8g/cm3,length is 48 mm, diameter is 16 mm, accelerationsensitivity is 340 mv/a.In order to reduce the effect of flow noise and elastic installation of acoustic sensor, in this paper, the acceleration sensor has be connected with theouter shell of acoustic vector sensor through the damping gaskets, at the same time, the outside of acceleration sensor is the sound pressure channelwrapped the rubber layer. The external piezoelectric ceramic rings formed sound pressure channel, scalar information can be achieved, internalacceleration sensor constitute one dimensional vector channel, vector information can be achieved.ResultsResultsResultsResultsThe co-vibrating acoustic vector sensor has been measured in the standing wave field. The test results show that the pressure sensitivity of sample isabout -195dB (re 200Hz). In atmospheric pressure the directivity meet the cosine directivity.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThis paper basis for the design theory of co-vibrating acoustic vector sensor, design and manufactured a high sensitivity and strong anti-jammingco-vibrating cylinder acoustic vector sensor, sensitivity is -195dB(re 200Hz)，and this vector sensor can be fixed installed, eliminating the adverseeffects from the suspension system of co-vibrating vector sensor.

Keywords:Keywords:Keywords:Keywords: co-vibrating acoustic vector sensor; fixed installation; high sensitivity; strong anti-jammingAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the Technology Foundation of Nation (No. J192013C001).


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THETHETHETHEMEASUREMENTMEASUREMENTMEASUREMENTMEASUREMENTOFOFOFOFELASTICELASTICELASTICELASTIC CONSTANTSCONSTANTSCONSTANTSCONSTANTSOFOFOFOFQUARTZQUARTZQUARTZQUARTZ CRYSTALCRYSTALCRYSTALCRYSTALBYBYBYBYRESONANTRESONANTRESONANTRESONANT

ULTRASOUNDULTRASOUNDULTRASOUNDULTRASOUND SPECTROSCOPYSPECTROSCOPYSPECTROSCOPYSPECTROSCOPY

Ji WANG*, Zhen WANG, Xiang-wu XU, Jian-ke DUPiezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics, Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211,China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveNowadays, for the design precision devices, it is essential to have accurate elastic constants of piezoelectric materials. However, traditional approach tomeasure both electrical and acoustic properties of different orientations and configurations involving lengthy time of sample preparation and expensivecosts. The method reported in this paper is based on the Resonant Ultrasound Spectroscopy (RUS) which allows to identify the elastic constants ofmaterials with only one single specimens. This method has been successfully applied to elastic materials and then extended piezoelectric samples andthe results are compared to FEM calculation. In the paper, we solved equations under trigonal crystal structure and extracted the elastic constants withthe new algorithm.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe determined the elastic constants of quartz crystal by calculating the spectrum of free vibration of quartz crystal specimens. We developed our ownFortran program for the trigonal crystal structure which is not included in the known RUS algorithms. Finally, the elastic constants of trigonal materialsare obtained with the RUS technology.ResultsResultsResultsResultsAfter inserted the Fortran program into RUS instrument, we compared resonance frequencies between the results and ANSYS. The results are veryclose to each other. We measured the elastic constants of quartz crystal with the configurations of cube, cylinder, and sphere respectively. The resultswe measured come into close agreement with the existed elastic constants.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsWe have successfully modified the RUS algorithm for the calculation of trigonal materials, and the data from the RUS measurement is in agreementwith earlier data. The current effort provides needed experiences and confidence for the future measurement of novel materials for possible applicationsin acoustic wave devices.

Keywords:Keywords:Keywords:Keywords: elastic constants; resonant ultrasound spectroscopyAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported in part by the National Natural Science Foundation of China (Grant No. 10932004, 11072116and 11272161) and the Ministry of Education of China (Grant No. 20093305110003). Additional support is provided by the K.C. Wong Magna Fund ofNingbo University, and Student Research and Innovation Program of Ningbo University.


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MAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTIC LAMINATEDLAMINATEDLAMINATEDLAMINATED PLATESPLATESPLATESPLATESWITHWITHWITHWITHANANANAN ELLIPTICALELLIPTICALELLIPTICALELLIPTICALHOLEHOLEHOLEHOLE

SUBJECTEDSUBJECTEDSUBJECTEDSUBJECTEDTOTOTOTOOUT-OF-PLANEOUT-OF-PLANEOUT-OF-PLANEOUT-OF-PLANE BENDINGBENDINGBENDINGBENDINGMOMENTSMOMENTSMOMENTSMOMENTS

Xiang-hua DAI, Cun-fa GAO*

State Key Laboratory of Mechanics and Control of Mechanical Structures, Nanjing University of Aeronautics &Astronautics, Nanjing 210016


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveIt is well known that piezoelectric and piezomagnetic materials have the ability of converting the system energy from one form (among magnetic,electric and mechanical energies) to the other. However, due to their brittleness, cracks and flaws are inevitably presented in suchmagneto-electro-elastic materials, which will cause high stress, electric and/or magneto field concentrations. Because of the multiple coupling effects, itseems the problems related to the magneto-electro-elastic composite laminates with cracks or inclusions are not easy to be solved analytically.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper through the classical Mushhelishvili-Lekhnitskii complex variable method, the Kirchhoff assumptions and exact boundary conditions, weobtain the Lekhnitskii solutions for the cylindrical bending of the piezoelectric and piezomagnetic laminates with an elliptic hole.ResultsResultsResultsResultsThe stress potential, deflection, electric and magnetic potential are firstly derived for the piezoelectric and piezomagnetic laminates subjected touniform bending moments at infinity. Then, the explicit expressions for the stresses, electric displacements and magnetic inductions around and outsidethe elliptic hole are also derived. Besides, numerical results for the stress distribution around the elliptic hole are presented to discuss the piezoelectricand piezomagnetic effects on the stress and moments.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsAccording to the results of the numerical calculation, it is found that the stress concentration near the hole depend on the material constants and the holegeometry.

Keywords:Keywords:Keywords:Keywords: magneto-electro-elastic composite laminates; elliptical hole; cylindrical bending; mushhelishvili-lekhnitskii complex variable methodAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10972103).

../Documents/Tencent Files/710888864/FileRecv/[email protected]


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THETHETHETHEANTI-PLANEANTI-PLANEANTI-PLANEANTI-PLANEVIBRATIONVIBRATIONVIBRATIONVIBRATIONOFOFOFOFQUARTZQUARTZQUARTZQUARTZ PLATEPLATEPLATEPLATEWITHWITHWITHWITHANANANANADDITIONALADDITIONALADDITIONALADDITIONALPARTIALPARTIALPARTIALPARTIAL

NON-UNIFORMNON-UNIFORMNON-UNIFORMNON-UNIFORMMASSMASSMASSMASS LAYERLAYERLAYERLAYER

Peng LI, Feng JIN*State Key Laboratory for Mechanical Structure Strength and Vibration, Xi’an Jiaotong University, Xi’an 710049


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveFrequency shifts in a crystal resonator or mass sensor that occurs due to a thin mass layer added to its surface is an important issue in frequencystability analysis of crystal resonators used for time-keeping and telecommunication. When a thin layer of another material is added to the surface of aresonator, the resonant frequencies become lower; that this primarily occurs because of the inertia of the mass layer is the simplest explanation(Sauerbery’s equation). This effect has been used to make mass sensors for measuring the density and thickness of the layer. For instance, quartz crystalmicrobalance (QCM) is used to detect the micro-mass changes and physical properties of thin layers deposited on crystal surfaces, which haveimportant applications in chemical and biological sensing devices.Sauerbery’s equation gives the linear relationship between the resonance frequency shift of QCM and mass attached on the electrode surface. However,this equation and its various refinements generally assume that the mass is uniform and fully attached to the QCM surfaces, and it is not a goodapproximation in practical application. It has been noted that Sauerbery’s equation can yield incorrect results when the mass and amplitude of vibrationdistribution are not uniform, and when the mass is not attached rigidly. When the mass layer is non-uniform or partially distributed on the plate surface,the first-order perturbation integral and Mindlin’s two-dimensional equation can be used to obtain the solution for thickness-shear vibration. Anotherapproximate solution can be obtained by dividing the mass layer into many subsidiary thinner layers. Most of the research works reported are withregard to the thickness-shear vibration. In reality, however, due to the finite sizes of devices, pure TSh modes cannot exist in finite crystal platesbecause of edge effects. To the best of the authors’ knowledge, there is a lack of relatively systematic theoretical results for the anti-plane vibration ofcrystal plate.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe anti-plane vibration of an AT-cut quartz plate having an additional partial non-uniform mass layer is solved using the Fourier sine and cosine seriessolution. The results can be reduced when applied to some special cases, such as the uniform or additional fully attached mass layer.ResultsResultsResultsResultsAfter the convergence is examined, some numerical simulations are carried out based on the solution, while including the frequency shift, the modenumber and the energy-trapping phenomenon. The results reported may enable applications of anti-plane vibrations of crystal devices, for example,QCM, resonators, mass sensors and so on.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe trigonometric series method, which gives good convergence and high precision, is employed for solving the problem of anti-plane vibration of aquartz plate, which is compose several types of additional partial non-uniform mass layers on its surface, with the interface perfectly bonding. Thefrequency spectrums with the length and mass fraction of mass layer are discussed separately. The energy-trapping phenomenon is displayed althoughthe mass layer is non-homogeneous. All the results obtained give theoretical guidance not only for physical phenomena explanations but also forexperimental measurement of layer properties in mass sensor devices.

Keywords:Keywords:Keywords:Keywords: anti-plane vibration; non-uniform mass layer; frequency shift; energy trappingAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11272247) and Scholarship Award forExcellent Doctoral Student granted by Ministry of Education.



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WAVEWAVEWAVEWAVE PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION ININININAAAA LAYEREDLAYEREDLAYEREDLAYEREDMAGNETO-ELECTRICMAGNETO-ELECTRICMAGNETO-ELECTRICMAGNETO-ELECTRIC HOLLOWHOLLOWHOLLOWHOLLOWCYLINDERCYLINDERCYLINDERCYLINDER

Yong-dong PAN1*, Zheng ZHONG1, Kao-shan DAI21 School of Aerospace Engineering and Applied Mechanics, Tongji University, Shanghai 200092

2School of Civil Engineering, Tongji University, Shanghai 200092

*Corresponding author, E-mail: [email protected].; Tel.: 86-021-65983797

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectivePiezoelectric and piezomagnetic materials are widely used to fabricate various sensors, conductors, and actuators, etc.. Recently, the layeredmagneto-electric plates have been successfully manipulated to improve the magneto-electric effects for various applications and the coupling betweenthe mechanic, electric and magnetic fields has been studied extensively. However, scientific research related to the coupling between the acoustic,electric and magnetic fields is limited, Understanding this coupling mechanism may play a role for the development of smart devices, e.g., activelytuning the acoustic wave propagation for possible smart acoustic filters and delay lines. Acoustic wave propagation within layered magneto-electrichollow cylinder was theoretically studied in this paper. The observations of this research pave the way for further laser ultrasonic investigation of thecoupling behaviors of the acoustic, electric and magnetic fields.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWave propagation in a layered magneto-electric hollow cylinder was decoupled into the SH wave and PSV wave propagation. Basic wave equationswere then formulated. Moreover, the state vector approach was used to derive the differential equations for the layered structures; and thecorresponding system matrices were developed. This work will facilitate further numerical calculations and experimental investigations.ResultsResultsResultsResultsSH and P-SV waves propagating along both the axial and circumferential directions of the layered magneto-electric hollow cylinder were formulatedexplicitly. The corresponding wave equations and system matrices were obtained. It is founded that the axially propagating SH wave and thecircumferentially propagating P-SV wave are not coupled to the electric and magnetic fields, i.e., the corresponding dispersion pattern is same as thatfor a layered hollow cylinder without any piezoelectricity and piezomagneticity. However, the axially propagating P-SV wave and the circumferentiallypropagating SH wave are coupled to the electric and magnetic fields, which was indicated by the observation that the corresponding dispersion patterndepends on the applied electric and magnetic field and the dispersion curves are different under the open and close electric boundary conditions ormagnetic field.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe results provide the theoretical base for the excitation and detection of the various SH and PSV waves in a layered magneto-electric hollow cylinder.It can be concluded that the piezoelectricity and piezomagneticity contribute to coupling when the orientation of the electric and magnetic fields areparallel to the displacement of the SH and PSV waves. The findings pave a way to implement the active tuning of acoustic wave propagations.

Keywords:Keywords:Keywords:Keywords: piezoelectricity; piezomagneticity; SH wave; P-SV wave; hollow cylinderAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10834009, 11090333) and theFundamental Research Funds for the Central Universities, Tongji University (0270219037).

mailto:[email protected].


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FIRSTFIRSTFIRSTFIRST PRINCIPLESPRINCIPLESPRINCIPLESPRINCIPLES STUDYSTUDYSTUDYSTUDYONONONON THETHETHETHE FLEXOELECTRICFLEXOELECTRICFLEXOELECTRICFLEXOELECTRIC COEFFICIENTSCOEFFICIENTSCOEFFICIENTSCOEFFICIENTS OFOFOFOF BARIUMBARIUMBARIUMBARIUMTITANATETITANATETITANATETITANATE

Tao XU, Jie WANG*Department of Engineering Mechanics, School of Aeronautics & Astronautics

Zhejiang University, Hangzhou, Zhejiang 310027, China

* Tel: +86-571-87953110, Fax: +86-571-87953110E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveFlexoelectricity describes the linear response of electric polarization to strain gradient, which has drawn more and more attention in recent scientific

studies due to its broad application potential in the functional devices of dielectrics. In contrast to piezoelectric effect, the flexoelectric effect is not

subjected to symmetry restriction due to the break of inversion symmetry by the strain gradient, that is, flexoelectricity can exist in all point groups

regardless of symmetry center.However, people was not consciously aware of the phenomenon for a long time, the main reason being that the

flexoelectric effect is negligible at the macro level. But it could be significantly enhanced at the nanoscale, where the huge strain gradient often presents,

exceeding those of epitaxial growth thin film. In this paper, we predict the flexoelectric coefficient of f3311 from the first principles calculation for the

first time. First-principles calculations are effective methods to gain an insight into the nature of ferroelectricity in the microscopic level.

StatementStatementStatementStatement ofofofof MethodsMethodsMethodsMethodsFlexoelectric coefficients associate the electrical polarization with strain gradient in the following relationship:

(1)

Where is the polarization induced by flexoelectric effect, is the strain gradient and the fourth rank tensor stands for flexoelectric

coefficients. In this paper, our main objective is to predict the transverse flexoelectric coefficient of in the following formula:

(2)

In the calculation we create the supercells in the form of（n+1）x 1 x m unit cells in x, y and z direction, that is, there are (n+1) unit cells , one unit cell

and m unit cells in x, y, z directions respectively. Then we apply a periodic strain in the x direction as to n unit cells

along z direction, and the strain of is applied to the remain unit cells on the edge row in one supercell in order to

satisfy the periodic boundary conditions. In addition, the cell length in y and z directions keep unrestrained.

In the calculation, Born effective charges is used to calculate the local polarization in each unit cell:

(3)

Once the polarization and strain gradient are known, we can easily obtain the flexoelectric coefficients by the definition.

ResultsResultsResultsResultsIn all cases(n=3,5,7,9 and m=8,12,16) of our calculations ,the unfixed atoms in the superlattice are relaxed to the stable state with the existence of strain

gradient. The strain gradient is a little smaller than that of the fixed case. However, the difference decreases with the increase of n and m. It shows that

such a difference is induced by the insufficient size of supercell. What’s more, the cells also appear cosine strain gradient in the z direction after

relaxation so that we should eliminate the contribution of the longitudinal flexoelectric polarization. In this case, we employ the longitudinal

flexoelectric coefficients f3333 obtained by Hong et al in the similar way to eliminate the longitudinal flexoelectric effect in total polarization. Finally, the

flexoelectric coefficient f3311 is calculated from the polarization and applied strain gradient.

The predicted flexoelectric coefficient is around 0.54nc/m, which is about three-order smaller than the experiment data in magnitude. However, it


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consists well with the theoretical estimation (i.e., f~e/a, where e is the electronic charge and a is the lattice constant) and also with the theoretical

calculations of Hong et al.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe transverse flexoelectric coefficient is predicted using first-principles calculation for the first time in the present study, which is an extension of the

atomic level studies in the literature. The discrepancy between the predicted coefficient and the experiment one attributes to the extreme sensitivity of

the soft optic mode to temperature in the perovskite ferroelectrics. In the present study, the coefficient is calculated at 0K, while the experimental one

was measured at room temperature. The present work provides new insights into flexoelectric effect from atomic point of view and pave the way for

further in-depth studies on this topic.

Keywords:Keywords:Keywords:Keywords: flexoelectricity; first-principles simulation; strain gradientAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was financially supported by the Nature Science Foundation of China under Grants (11002123, 11090333) andZhejiang Provincial Natural Science Foundation under Grant R6110115.


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EFFECTSEFFECTSEFFECTSEFFECTSOFOFOFOFELASTICELASTICELASTICELASTICMATRIXMATRIXMATRIXMATRIX ONONONON LONGITUDINALLONGITUDINALLONGITUDINALLONGITUDINALWAVEWAVEWAVEWAVE PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATION

ININININ NANONANONANONANO SCALESCALESCALESCALE PLATEPLATEPLATEPLATE

Yi-ze WANG1*, Feng-ming LI2*1 P. O. Box 137, School of Astronautics, Harbin Institute of Technology, Harbin 1500012College of Mechanical Engineering, Beijing University of Technology, Beijing 100124

*Corresponding authors, E-mail: [email protected] (Y.-Z. Wang), [email protected] (F.-M. Li)

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSince the pioneer work by Iijima, nano scale structures have attracted a lot of attention. The nonlocal continuum theory which is presented by Eringenassumes the stress at a reference point as a function of the strain at every point in the body. Therefore, the nonlocal elastic model is more suitable forthe mechanical properties of nano structures.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsAs the typical case, the vibration and wave propagation for the axial and longitudinal mode in nano structures have been analyzed in detail. In ourprevious work, the longitudinal wave in the nano plate is investigated. However, it’s a pity that the elastic medium around are not considered. In thepresent paper, the effects of elastic matrix on the same mode are discussed. From the results, some new and interesting phenomena can be observed.ResultsResultsResultsResultsIt can be observed that the wave frequency becomes lower with the matrix stiffness increasing, which is obvious for larger wave numbers. The phasevelocity can be reduced by the increasing the matrix stiffness. Moreover, both the frequency and phase velocity decrease with the scale coefficientbecoming larger.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe matrix stiffness has significant influences on the longitudinal wave in nano scale plate embedded in elastic matrix. Furthermore, the classical modelwill present a higher result for both frequency and phase velocity but the nonlocal continuum can give a suitable approximation.

Keywords:Keywords:Keywords:Keywords: nano scale plate; nonlocal continuum theory; longitudinal wave; elastic matrixAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The authors wish to express gratitude for the supports provided by the National Natural Science Foundation of Chinaunder Grant Nos. 11002045, 11172084, 10632020 and 10672017 for this research work. Yi-Ze Wang also would like to acknowledge the supportsprovided by Harbin Institute of Technology under Grant Nos. HIT.KLOF.2012.082 and HIT.BRETIII.201213.




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THETHETHETHE FINITEFINITEFINITEFINITE ELEMENTELEMENTELEMENTELEMENTANALYSISANALYSISANALYSISANALYSIS OFOFOFOFULTRASONICULTRASONICULTRASONICULTRASONIC REFLECTIONREFLECTIONREFLECTIONREFLECTIONMETHODMETHODMETHODMETHODUSEDUSEDUSEDUSED ININININ

ACOUSTICACOUSTICACOUSTICACOUSTIC LOGGINGLOGGINGLOGGINGLOGGING

Zhi-feng SUN*, Hong-hai CHEN, Xi-en LIUChina Oilfield Services Limited, Beijing 101149


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveTransducer size, frequency and casing curvature have a great influence on ultrasonic wave propagation in casing well. This article simulates acousticpropagation of plane ultrasonic transducer in multilayer medium in casing well by using the finite element method.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsEffects of transducer length on resonance wave of casing and frequency spectrum is studied in cases of both free pipe and well-bonded cement. Therelation between transducer length and energy of resonance wave is discussed. Effect of casing curvature on amplitude of reflection wave andfrequency spectrum of resonance wave is also studied.ResultsResultsResultsResultsIn free pipe or in well-bonded cement, with the increase of transducer length, reflection wave and resonance wave signals are gradually increasing, andleakage peaks of reflected wave spectrum changes from single mode to multiple. With transducer length increases, resonance wave amplitude decreases,and it increases to a certain extent, resonance wave amplitude change shock. With casing curvature decreases, signals intensity of reflection wave andresonance wave increase, and leakage peaks of frequency spectrum changes from multiple to a single mode.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsLarger transducer chip will make refractive shear in casing, and has also a little distinguishing ability for acoustic impedance of interface betweencasing and cement ring. Casing curvature has a certain effect on resonance wave of casing. A smaller length transducer should be selected in theassurance of ultrasonic excitation intensity.

Keywords:Keywords:Keywords:Keywords: ultrasonic pulse echo; casing curvature; finite element analysis; acoustic loggingAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Key Projects (No. 2011ZX05020-005) and the National High TechnologyResearch and Development Program of China (No. SQ2010AA0920229001).



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TWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALTWO-DIMENSIONALMINDLINMINDLINMINDLINMINDLIN PLATEPLATEPLATEPLATE EQUATIONSEQUATIONSEQUATIONSEQUATIONS OFOFOFOFVIBRATIONSVIBRATIONSVIBRATIONSVIBRATIONS OFOFOFOFCIRCULARCIRCULARCIRCULARCIRCULAR

ELASTICELASTICELASTICELASTIC PLATESPLATESPLATESPLATES

Ji WANG*, Wen-jun WANG, Gui-jia CHEN, Ting-feng MA, Jian-ke DUPiezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics Ningbo University, Ningbo, Zhejiang, 315211, CHINA


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe piezoelectric devices have a wide variety of applications in communications, aviation, navigation, instrumentation, and computers, and the trend ofthe development is to produce more accurate and stable devices at a lower cost. To achieve this goal, efforts have to be made on accurate numericalmodels of piezoelectric devices based on plate elements with different configurations. We extend the systematic analysis of high frequency vibrationsof plates for rectangular type resonators to circular plates for the refined analysis of circular plates with further objective of overtone mode vibrations.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe systematic derivation of Mindlin plate equations has been fully presented in the monograph of Mindlin and some of his papers. Most applicationsafterwards are focused on the straight-crested wave in rectangular quartz crystal plates due to the necessity in the design of rectangular type resonatorsand relative simplicity of analysis. Some applications concerning circulate plates vibrating at the thickness-shear mode or the shear effects areanalyzed by transforming the relatively simple equations of the thickness-shear and flexure modes to the cylindrical coordinates with a simpleprocedure, as we can find from a few papers and books. The systematic derivation by following rigorious procedure of Mindlin plate equations arenot presented before, and subsequent applications to coupled vibrations of circular plates at thickness-shear modes have not be studied with theMindlin plate equations for circular type quartz crystal resonators. Particularly, vibrations of overtone modes with more coupled displacementsrequire a systematic derivation which is more clear if derive from the cylindrical coordinates. We completed the procedure of the derivation ofMindlin plate equations with circular plates in this study.ResultsResultsResultsResultsA complete set of two-dimensional Mindlin plate equations for circular plates with the cylindrical coordinates are obtained. The plate equations havealso been truncated by following the procedures outlined by Mindlin, thus resulting a set of simplified equations for the high frequency equations ofcircular plates. These equations are particularly useful for the analysistical studies of quartz crystal resonators of circular type at the overtonevibrations.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe derivation is based on the same procedure for rectangular plates, and the essential vibrations of circular plates are analyzed in the cylindricalcoordinates. The truncated and simplified equations will find similar applications in the studies of circular quartz crystal resonators.

Keywords:Keywords:Keywords:Keywords: elastic plates; Mindlin plate theory; equations; cylindrical coordinatesAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work is supported in part by the National Natural Science Foundation of China (Grant Nos. 10932004 & 11072116)and the Ministry of Education of China (Grant No. 20093305110003). Additional support is provided by the K.C. Wong Magna Fund of NingboUniversity.



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FREQUENCY-TEMPERATUREFREQUENCY-TEMPERATUREFREQUENCY-TEMPERATUREFREQUENCY-TEMPERATUREANALYSISANALYSISANALYSISANALYSIS OFOFOFOFTHICKNESS-SHEARTHICKNESS-SHEARTHICKNESS-SHEARTHICKNESS-SHEARVIBRATIONSVIBRATIONSVIBRATIONSVIBRATIONSOFOFOFOFSC-CUTSC-CUTSC-CUTSC-CUT

PLATESPLATESPLATESPLATESWITHWITHWITHWITHTHETHETHETHE FIRST-ORDERFIRST-ORDERFIRST-ORDERFIRST-ORDERMINDLINMINDLINMINDLINMINDLIN PLATEPLATEPLATEPLATE EQUATIONSEQUATIONSEQUATIONSEQUATIONS

Ji WANG*, Wen-jun WANG, Gui-jia CHEN, Jian-ke DU, Ting-feng MAPiezoelectric Device Laboratory, School of Mechanical Engineering & Mechanics Ningbo University, 818 Fenghua Road, Ningbo, Zhejiang 315211, CHINA


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe analysis of quartz crystal resonators requires detailed solutions of vibration frequency and mode shapes of all vibration modes for the optimaldesign of resonator structures with the presence of thermal field. The vibration analysis should be done in different stages starting from free vibrationsinvolving mechanical variables and gradual consideration of electrical field and other factors such as electrodes, temperature, and supporting structures.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA procedure has been established for the calculation of dispersion relations, frequency spectra, selected vibration modes, and analysisfrequency-temperature behavior of free vibrations of SC-cut quartz crystal plates with the incremental thermal field theory proposed by Lee and Yongwith the material constants. Similar analysis to the AT-cut quartz crystal plates has been successful and applications to the SC-cut plates are equallyin demands for the circular resonator design and analysis. By utilizing the Mindlin plate equations with corrections and truncation, we have completedthe vibration analysis of partially plated SC-cut quartz crystal plates as needed in resonator design, and the frequency-temperature analysis with theincremental thermal field theory will provide further vital reference.ResultsResultsResultsResultsWith the incremental thermal field and associated material constants, we have truncated equations for the analysis of thickness-shear vibrations ofSC-cut crystal plates. By assuming straight-crested waves in a rectangular plate, we can obtain the frequency-temperature relations of thethickness-shear mode to study the effect of plate configurations as well as the electrodes. As before, such results will be useful in the accuratedetermination of resonator structures.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe incremental thermal field theory has been successfully adopted for the analysis of vibrations of quartz crystal plates of AT-cut as part of the designprocess of resonators. Through adopting the thermal elastic constants for the SC-cut and newly obtained equations, we can now perform the sameanalysis to the SC-cut crystal plates. The results, upon validation from measurements, will be important in the resonator design process.

Keywords:Keywords:Keywords:Keywords: SC-cut plate; Mindlin plate theory; vibration analysis; frequency-temperature behaviorAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work is supported in part by the National Natural Science Foundation of China (Grant Nos. 10932004 & 11072116)and the Ministry of Education of China (Grant No. 20093305110003). Additional support is provided by the K.C. Wong Magna Fund of NingboUniversity.



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DESIGNDESIGNDESIGNDESIGNANDANDANDANDANALYSISANALYSISANALYSISANALYSIS OFOFOFOFAAAA SELF-SENSINGSELF-SENSINGSELF-SENSINGSELF-SENSING SMARTSMARTSMARTSMARTTOOLTOOLTOOLTOOLINTERGRATEDINTERGRATEDINTERGRATEDINTERGRATED

PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC FLIMSFLIMSFLIMSFLIMS FORFORFORFORCUTTINGCUTTINGCUTTINGCUTTING FORCEFORCEFORCEFORCEMONITORINGMONITORINGMONITORINGMONITORING ININININ ULTRA-PRECISIONULTRA-PRECISIONULTRA-PRECISIONULTRA-PRECISION

MACHININGMACHININGMACHININGMACHINING

Cai-wei XIAO1*, Kai CHENG1,2, Ding HUI1, Shi-jin CHEN1

1School of Mechatronics Engineering, Harbin Institute of Technology, Harbin, 150080, China2School of Engineering and Design, Brunel University, Uxbridge, Middlesex UB8 3PH, UK


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveCutting force monitor is the most effective method to estimate cutting tool condition in the cutting process which has been well recognized bymachining communities. At present, it is highly desired to develop the real-time process monitoring systems which satisfy the demand of the largesurface consistency processing, constant cutting force machining, cutting surface quality control and adaptive smart machining in ultra-precisionmachining. So it’s necessary to develop a smart tool which can real-time monitor cutting forces and have no additional equipment; minimummodification of tool; easy to install and employ and low cost.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA self-sensing smart tool was proposed and designed for monitoring cutting forces which integrate the sensors using piezoelectric films into the specialdesigned insert tool with two strain cavities for piezoelectric films placed. Piezoelectric films generate electrical signals according to the piezoelectriceffect when subject to small strain of the insert tool, due to cutting loads of tool nose. The output electrical signals can be amplified and processed tocapable of monitoring cutting forces. The FE-model of smart tool was established and structural mechanics and piezoelectric coupling analysis wereimplemented considering different mechanical load conditions using simulation software Ansys.ResultsResultsResultsResultsThe multi-physics coupling FE-model based on piezoelectric-structural interaction is established to verify the structure reliability of the smart tool andthe validity of the proposed method. The FE-simulation results that the structure of smart tool has well mechanical performance, no weakness thestiffness and strength, and output charges obtained from the sensors agree with the different mechanical loads within an acceptable accuracy. Therelationship between output charges and cutting forces almost is a linear proportional capable to monitor the cutting force signals.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThis paper proposed the novel self-sensing smart tool for monitoring cutting force in ultra-precision machining, which integrate the sensors usingpiezoelectric films. The special designed insert tool has been presented, which has two small and special stress cavity structures so as to improve themeasure sensitivity. The FE-simulation based on multi-physics coupling model of smart tool results illustrate the relationship between different cuttingforce and electrical signals and can be used reliably to monitoring the cutting force. In particular, the self-sensing smart tool is able to measure the smallloads and low force variations. Future works will mainly focus on optimization of smart tool size to obtain better sensitivity, analysis of heat effect forbetter stability.

Keywords:Keywords:Keywords:Keywords: smart tool; piezoelectric films; cutting force monitoring; multi-physics coupling model.


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THICKNESS-SHEARTHICKNESS-SHEARTHICKNESS-SHEARTHICKNESS-SHEARANDANDANDANDTHICKNESS-TWISTTHICKNESS-TWISTTHICKNESS-TWISTTHICKNESS-TWISTMODESMODESMODESMODES ININININANANANANOBLATEOBLATEOBLATEOBLATE ELLIPTICALELLIPTICALELLIPTICALELLIPTICAL

CERAMICCERAMICCERAMICCERAMIC CYLINDERCYLINDERCYLINDERCYLINDERANDANDANDAND ENERGYENERGYENERGYENERGYTRAPPINGTRAPPINGTRAPPINGTRAPPING ININININ CONTOUREDCONTOUREDCONTOUREDCONTOUREDACOUSTICACOUSTICACOUSTICACOUSTICWAVEWAVEWAVEWAVE

RESONATORSRESONATORSRESONATORSRESONATORS

Hui-jing HE1, Jia-shi YANG1*, Yi-hua HUANG2

1Department of Mechanical and Materials Engineering,University of Nebraska-Lincoln, Lincoln, NE 68588-0526, USA2Department of Electronic and Communication Engineering, Sun Yat-sen University, Guangzhou 510006


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThickness-shear and thickness-twist modes of crystal plates are the modes used most often as the operating modes of bulk acoustic wave resonators. Animportant behavior of these modes is the energy trapping phenomenon in which the vibration is confined to be near the center of the plate. Near theedge of the plate there is essentially no vibration left so that mounting at the edge does not affect the vibration of the plate. Energy trapping can becaused by the mass effect of the electrodes deposited near the center of the plates. Contoured plates with varying thickness can also produce strongenergy trapping when the plates are thicker near the center. Energy trapping has been under sustained study theoretically, numerically, andexperimentally. It has become more crucial with the miniaturization of resonators. Most of the theoretical results in the literature on energy trapping areapproximate and are for elastic plates. We attempt to perform an exact piezoelectric analysis of energy trapping for thickness-shear and thickness-twistmodes in a ceramic cylinder with an oblate elliptical cross section as a contoured resonator.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe use elliptical coordinates for the elliptical cross section of the cylinder. Thickness-shear and thickness-twist modes belong to the so-calledshear-horizontal or antiplane motions. They are governed by differential equations with two-dimensional Laplacian operators. These equations areseparable in elliptical coordinates. This allows us to solve the governing equations over the elliptical cross section by the method of separation ofvariables in partial differential equations. The procedure involves the calculation of various Mathieu’s functions.ResultsResultsResultsResultsExact thickness-shear and thickness-twist modes are obtained for an oblate elliptical cylinder. They are exact in the sense that they satisfy thethree-dimensional equations of linear piezoelectricity and their boundary conditions. Both electroded and unelectroded cylinders are considered.Displacement and potential fields for modes of various orders are calculated.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsOur numerical results show that thickness-shear and thickness-twist modes in an oblate elliptical cylinder exhibit strong energy trapping. Higher-orderthickness-shear modes with more nodal points (zeros) along the plate thickness have rapidly increasing frequencies and are better trapped. Higher-orderthickness-twist modes with more nodal points along the plate middle plane have slowly increasing frequencies and are less trapped. The modesobtained provide basic understanding of energy trapping in contoured acoustic wave resonators. The results are valid for both polarized ceramics andcrystals of class 6mm including ZnO and AlN for thin film acoustic wave resonators (FBARs) of current research interest.

Keywords:Keywords:Keywords:Keywords: shear horizontal; plate; vibration; thickness shear; energy trappingAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was partially supported by the US Army Research Laboratory/US Army Research Office under agreementnumber W911NF-10-1-0293.


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OVERTONE-MODEOVERTONE-MODEOVERTONE-MODEOVERTONE-MODELIMITSLIMITSLIMITSLIMITS ONONONONAT-CUTFUNDAMENTALAT-CUTFUNDAMENTALAT-CUTFUNDAMENTALAT-CUTFUNDAMENTALCRYSTALCRYSTALCRYSTALCRYSTALRESONATOR,RESONATOR,RESONATOR,RESONATOR,

THROUGHTHROUGHTHROUGHTHROUGHTWICETWICETWICETWICE PLATINGPLATINGPLATINGPLATINGMETHODMETHODMETHODMETHOD

Lin-lin ZHANGBeijing Chenjing Electronics co., Ltd


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSometimes we may encounter such a situation, overtone mode appeared when the crystal resonators were designed to work in desired fundamentalmode. Generally, fundamental circuit does not have an LC circuit; with the highly frequency-impedance dependence, crystal resonator will work in theminimum impedance mode. In most cases, impedance of AT-cut overtone mode crystal resonators closes to that of the fundamental mode. Thereforethe above phenomenon occurred.This paper introduces a new method of overtone-mode limits on the AT-cut fundamental crystal resonators.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsUsing the energy trapping theory, we can achieve the overtone-mode limits through a new electrode design. Energy trapping theory shows that: 1.Thewave can only spread above the frequency which called limiting frequency; so that stationary wave and vibration will form; the below ones will presentexponential decay. 2. The energy trapping coefficient decreases as the overtone order decreases; consequently, the trapped energy of the fundamentalmode may be weaker than that of overtone mode; that is why the energy of overtone mode mostly concentrates on electrode region.According to the above theory, twice plating method is employed to realize the overtone mode limits. Here the twice plating would be different shape,different size, different thickness, but the same materials. Crystal blanks may be plated basic film with basic size and thickness as usual; then adopt thesame technology to form the second film with special size and thickness, which have be designed at the initial. Two key design parameters are thethickness ratio and the size ratio of twice plating, which are determined so that the maximum ratio of the impedance at the overtone mode to that at thefundamental mode may be achieved.ResultsResultsResultsResultsThough the theoretical calculation, a number of experiments were carried out to verify the effectiveness. Results showed that the impedance of overtonemode may be several times larger than that of the fundamental mode, when the thickness and size ratios between the second film and basic film presenta special proportion.Experimental results in AT-cut 4MHz fundamental mode have shown that impedance of overtone mode is almost ten times larger than that of thefundamental mode.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe energy trapping theory of quartz crystal has solved a number of application problems; including spurious response inhibition, fundamentalsuppression. The majority were achieved by means of electrode design and mass load. Unfortunately, most of the above only stay at the experimentlevel. This paper also uses the energy trapping theory to realize the overtone mode limits through a new electrode design. It was not only certificated byexperiment, but has been applied to the manufacturing field. A small number of users have been using this kind of products. This is the way to reflectthe value of design.

Keywords:Keywords:Keywords:Keywords: energy trapping theory; twice plating; impedance; overtone mode; fundamental modeAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by Beijing Chenjing Electronics co., Ltd.



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PRESSURE-INDUCEDPRESSURE-INDUCEDPRESSURE-INDUCEDPRESSURE-INDUCED ENHANCEMENTENHANCEMENTENHANCEMENTENHANCEMENTOFOFOFOFPIEZOELECTRICITYPIEZOELECTRICITYPIEZOELECTRICITYPIEZOELECTRICITY

OFOFOFOFQUARTZ-LIKEQUARTZ-LIKEQUARTZ-LIKEQUARTZ-LIKE SINGLESINGLESINGLESINGLE CRYSTALSCRYSTALSCRYSTALSCRYSTALS

Kai-nan XIONG, Su-xian CUI, Yan-qing ZHENG*, Er-wei SHIShanghai Institute of Ceramics, Chinese Academy of Sciences, Jiading, Shanghai 201800, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe piezoelectricity of a crystal is often affected by its form (such as bulk single crystal, low dimension materials, epitaxial thin films and so on) andpressure, stress and strain it bearing.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, by first-principles calculation, the piezoelectricity of quartz-like crystal, synthetic quartz, AlPO4, GaPO4, GaAsO4 and GeO2, wasinvestigated with virtual isostatic pressure.ResultsResultsResultsResultsThe virtual negative pressure changes its structure close to high temperature quartz phase with a higher symmetry, which leads to first-order phasetransition and normal strain piezoelectric coefficient along a-axis disappearing eventually. The piezoelectricity is related closely with tetrahedrontorsion angle which is used for characterizing the degree of divergence from centrosymmetry. Uniaxial stress or other non-isostatic pressure can alsolead to this kind of enhancement or declining, which is a general phenomenon. For a specific type of structure, piezoelectric coefficient can berepresented as a simple function of pressure or order parameter. Furthermore, the contribution of piezoelectric effect can be divided into two parts,clamping ion contribution and internal strain contribution. Then the internal strain contribution is divided to each ion of unit cell to get microscopicpiezoelectric coefficient of every ions and oxygen tetrahedrons.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsBy compared variation of tetrahedron torsion angles and microscopic piezoelectric coefficients of these five kinds of crystal, we get an explanation ofthe relationship between structure parameters and piezoelectric effect of quartz-like crystals in microscopic level.

Keywords:Keywords:Keywords:Keywords: quartz; piezoelectricity;pressure; first-principlesAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 50772121 and 50802104) and theKnowledge Innovation Program of Chinese Academy of Science under Grand No. KGCX-2-YW-206.


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SCATTERINGSCATTERINGSCATTERINGSCATTERING PROBLEMPROBLEMPROBLEMPROBLEMOFOFOFOFTHETHETHETHE INTERFACEINTERFACEINTERFACEINTERFACE CIRCULARCIRCULARCIRCULARCIRCULAR CAVITYCAVITYCAVITYCAVITY

ININININ PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICMEDIAMEDIAMEDIAMEDIA

Lei LIU, C. F. GAO*

State Key Laboratory of Mechanics and Control of Mechanical StructuresNanjing University of Aeronautics &Astronautics, Nanjing 210016

*Corresponding author, E-mail:[email protected]; Tel.: 025-84896237

MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveWave propagation in piezoelectric materials has received considerable attention due to the increasing use of smart materials such as electromechanicalsensors, transducers and actuators. These devices are designed to work under combined electro-mechanical loads. But such as dislocations,cracks andinclusions can greatly influence their characteristics and coupled behavior. Therefore, it is important to study the wave propagation about piezoelectricmaterials.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on Green function, the scattering problem of plane SH wave in piezoelectric materials is studied. First，in terms of wave functions expansionmethod, a construction method is given for the Green’s function. Green’s function is a solution of displacement field and electric potential field for anelastic half space with a half cylindrical cavity subjected to a time-harmonic out-plane line source loading at horizontal surface. Then，refraction waveand reflection wave of piezoelectric material and solution of electromechanical field are investigated. By combining two half spaces with unknownloading at interface into an infinite elastic piezoelectric body, the interface circular cavity can be formed. Integral equations to determine the unknownloading are established by use of Green’s function.ResultsResultsResultsResultsThrough integral equations, the deflection, electric potential are derived. And then, the expressions for the stresses and electric displacements aroundthe circular cavity are also derived.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsSome examples are given to show how the influence of the material parameters of different piezoelectric media parameters upon dynamic concentrationfactors.

Keywords:Keywords:Keywords:Keywords: piezoelectric materials; SH wave; Green’s function；dynamic stress concentration factor; interface circular cavity

../Documents/Tencent%20Files/710888864/FileRecv/[email protected]


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ENERGYENERGYENERGYENERGYHARVESTINGHARVESTINGHARVESTINGHARVESTING USINGUSINGUSINGUSINGAAAACANTILEVERCANTILEVERCANTILEVERCANTILEVER STRUCTURESTRUCTURESTRUCTURESTRUCTURE BASEDBASEDBASEDBASEDONONONONTHETHETHETHE SHEARSHEARSHEARSHEARMODEMODEMODEMODE

OFOFOFOF0.71Pb(Mg0.71Pb(Mg0.71Pb(Mg0.71Pb(Mg1/31/31/31/3NbNbNbNb2/32/32/32/3)O)O)O)O3333-0.29PbTiO-0.29PbTiO-0.29PbTiO-0.29PbTiO3333 SINGLESINGLESINGLESINGLE CRYSTALCRYSTALCRYSTALCRYSTAL

Zhu LIANG1,2, Bo REN 1, Chun-dong XU1,2, Xiang-yong ZHAO1, Hao-su LUO1*

1Key Laboratory of Inorganic Functional Material and Device, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai 201800, China2Graduate School of the Chinese Academy of Sciences, Beijing 100049, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveEnergy harvesting is a hot topic in recent years, several techniques can be used to convert the ambient energy into electrical energy such aspiezoelectric, electromagnetic and electrostatic transducer, but using piezoelectric effect is the most popular choice which well adapts to theapplications of micro power suppliers. The harvested energy can replace the battery and be used as a power supply for autonomous wireless sensors andwearable electronics.PZT ceramics, piezoelectric films, polyvinylidene fluoride (PVDF) and piezoelectric fibers were widely used in piezoelectricenergy harvesting systems. It was reported that the relaxor piezoelectric single crystal material (1-x)Pb(Mg1/3Nb2/3)O3-xPbTiO3 (PMN-xPT) hasultrahigh piezoelectric and electromechanical coupling properties (d33 and k33 could reach as high as 2500 pC/N and 0.94, respectively), more and moreresearchers were interested in designing and fabricating high-efficiency piezoelectric transducers and energy harvesters using PMN-xPT. However,seldom study was reported about the application based on the single PMN-0.29PT crystal with shear mode which has an even higher piezoelectricproperties (d15 and k15 could reach as high as 5980 pC/N and 0.97, respectively). On the other hand, Cantilever structure consisting of a piezoelectricbeam and a proof mass at the end is an effective way to lower the resonance frequency for the piezoelectric energy harvesters. Considering that thestress of the cantilever beam gradually increases from the base to the end along the length direction, the PMN-xPT single crystal shim could be sticknear the base to get largest stress during the vibration. In this work, we proposed a unimorph bender as a cantilever beam structure for harvestingmechanical energy based on the shear mode of PMN-0.29PT single crystal.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn the experiment, the 0.71PMN-0.29PT crystal was grown by a modified Bridgman technique, and then cut into wafers 13mm×6mm×1mm with theorientations of [111]/ [11 2 ]/ [110], which is the best orientation for shear mode usage. The silver electrodes were firstly painted on the [110] platesand fired at 700°C for 30 min. Then, the [110] plates were polarized in silicon oil under an electric voltage of 2.8 kV for 15 min at 120°C. The silverelectrodes were grinded off and the cold silver slurry were then printed on the [111] plate. The d15 piezoelectric coefficient of the polarized PMNTcrystal plates was measured to be 3080 pCN-1 by an Agilent 4294A impedance analyzer according to the IEEE standard and the k15 was calculated to be0.932.The plate was bonded and together with a brass shim (50.0 mm×6.0 mm×0.3 mm) at the base end using a silver-loaded epoxy (Applied ProductsE-Solder 3021). A proof mass was boned at the other tip of the brass shim.ResultsResultsResultsResultsA maximum output power of 4.16 mW and a peak voltage of 91.2 V were obtained from the device at 60 Hz with a matching load resistance of 1 MΩ,when bonding a proof mass of 0.5 g at the end of the brass shim and a 0.05 N peak value of the cyclic excitation force was applied. Another power andvoltage peak (0.22 mW and 10.1 V, respectively) were observed at 350 Hz. The maximum outputs were remarkably enhanced compared with thedevice without proof mass.Compared with the cantilever device based on the transverse mode (31-mode) PMN-PT single crystal (13.0 mm×6.0mm×1.0 mm) with a proof mass of 0.5-1.25g, the smaller size cantilever we introduced here (50.0 mm×6.0 mm×0.3 mm with a proof mass of 0.5g) cangenerate much higher power output , 4.16 mW at 60 Hz to 0.586 mW at 174 Hz.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn summary, a vibration energy harvesting device using the cantilever bender based on the shear mode of PMN-PT single crystal has been designed andfabricated. The electrical properties under different frequencies, load resistances, and proof masses were studied systematically. The device can givelarge output voltage and power due to the high piezoelectric constant of the material and the flexible performance of the structure. Also, the flexiblestructure makes the resonance frequency very low. Under the cyclic force of 0.05 N peak value, the device with a 0.5 g proof mass can generate a peakvoltage of 91.2 V and a maximum power of 4.16 mW at 60 Hz with a matching load resistance of 1 MΩ. This proposed device has the potential to beapplied to low-power portable electronics and wireless sensors.

Keywords:Keywords:Keywords:Keywords: energy harvesting; piezoelectric; PMN-xPT; shear modeAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was financially supported by the Ministry of Science and Technology of China through 973 Program (No.2009CB623305) and National Key Technology R&D Program (No. 2010BAK69B26), the Natural Science Foundation of China (Nos. 60837003,61001041 and 11090332), Science and Technology Commission of Shanghai Municipality (Nos. 10520712700, 10JC1415900 and 10dz0583400), theInnovation Fund of Shanghai Institute of Ceramics (Nos. O99ZC4140G and O99ZC1110G), Shanghai Rising-Star Program (No. 11QA1407500), andOpen Project from Shanghai Institute of Technical Physics, CAS (No. IIMDKFJJ-11-08).



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ACOUSTICACOUSTICACOUSTICACOUSTIC PROPERTYPROPERTYPROPERTYPROPERTYOFOFOFOFSLIGHTLYSLIGHTLYSLIGHTLYSLIGHTLYCOMPRESSIBLECOMPRESSIBLECOMPRESSIBLECOMPRESSIBLE POROUSPOROUSPOROUSPOROUSMEDIAMEDIAMEDIAMEDIAANDANDANDANDUNDERWATERUNDERWATERUNDERWATERUNDERWATERSTRUCTURE-BORNESTRUCTURE-BORNESTRUCTURE-BORNESTRUCTURE-BORNE NOISENOISENOISENOISE REDUCTIONREDUCTIONREDUCTIONREDUCTION

Bo QIN*

College of Aerospace Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016

*E-mail: [email protected]; Tel.: 13601589360

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveNoise radiated from the working ship hull has been studied for many years because of its widely application. There are usually two ways to reduce thesound radiated from the ship shell. One way is to optimize the inner structure designation and improve the ship’s power system. The other way is tocoat the shell with an acoustical baffle layer to reduce the structure-borne noise radiated to the water. According to acoustic theory, the soundimpedance of the baffle layer should be farthest mismatch with the impedance of water and hull of ship. The optimal case is that there is a layer of air oreven vacuum between the ship hull and water. However, any single solid media cannot satisfy the condition.The acoustic properties of slightly compressible viscoelastic medium permeated with air-filled micro-bubbles have been studied in detail in recent years.This material has some special acoustic properties owing to the multi-scattering and nonlinear oscillation of bubbles. The effective sound velocity andimpedance are very small at low frequency range and mismatch with the water and ship hull’s velocity and impedance. Thus, the slightly compressibleporous material can be used as the baffle layer to reduce the underwater structure-borne noise.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe slightly compressible media permeated with air-filled micro-bubbles has strong dispersive and strong nonlinear. The effective sound speed can beacquired by effective medium method. In this paper, the slightly compressible porous media is used as the baffle layer. Based on the acoustic waveequations, boundary condition and continuous condition, the infinite long cylindrical shell is used as the model to analyze the reduction ofstructure-borne noise generated by an axially symmetric ring force. The noise reduction is evaluated by the insertion loss which is defined as the ratio ofthe pressure at the standoff distance in the presence of the baffle layer to the pressure at the standoff distance in the absence of baffle layer. In numericalsimulation of noise reduction, as a parameter is varied, all other parameters keep invariable.ResultsResultsResultsResultsThe noise reduction varying with the porosity, thickness, damping and shear modulus of matrix are simulated and analyzed in detail. The effects ofnoise reduction also vary with the sound frequency. Numerical results have confirmed that the underwater structure-borne noise can be reducedeffectively by the porous media.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe acoustic property of slightly compressible medium permeated with air-filled micro-bubbles is analyzed. It has strong dispersive and its effectivevelocity can be obtained by effective medium method. As a new type of baffle layer material, the underwater structure-borne noise reduction for infinitelong cylindrical shell excited by an axially symmetric ring force is studied. Numerical simulation has confirmed that the slightly compressible porousbaffle layer can reduce the structure-borne noise effectively except at very low and resonant frequency of cylinder shell. The porosity, thickness ofbaffle layer and shear modulus of matrix have great effects on the structure-borne noise reduction. And the larger porosity, the thicker baffle layer andthe lower shear modulus of matrix are more suitable for structure-borne noise reduction. This work is helpful in designing the material for underwaternoise reduction.

Keywords:Keywords:Keywords:Keywords: slightly compressible medium; porous media; structure-borne noiseAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11172132).



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UHFUHFUHFUHFSAW-BASEDSAW-BASEDSAW-BASEDSAW-BASED RFIDRFIDRFIDRFIDWITHWITHWITHWITH INTEGRATEDINTEGRATEDINTEGRATEDINTEGRATEDANTENNAANTENNAANTENNAANTENNA

Duo LIU 1*, Xin-en ZHU 1, Tao HAN 2

1UM-SJTU Joint Institute, Shanghai Jiao Tong University, Shanghai 2002402Department of Instrument and Science, Shanghai Jiao Tong University, Shanghai 200240

*Corresponding author, E-mail:[email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSurface acoustic wave (SAW) based RFID has emerged as a substitutive technology to the traditional silicon based RFIDs due to the followingadvantages: passive operation, working at a large temperature range, and cost effective fabrication. In order to fulfill the demands of a longer readingrange and faster reading speed, UHF band has been a popular choice for the system operating frequency. Both the antenna performance and SAW RFIDbehavior change with respect to the temperature variation. The resultant impedance mismatch between the antenna and the SAW RFID will decreasethe effective reading distance. To solve this problem, we propose a fully integrated RFID for size miniaturization and an antenna/SAW deviceco-design and tuning strategy to compensate the mismatch caused by the temperature variation.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIntegration of this antenna with the SAW RFID is achieved through fabricating the antenna and SAW on one substrate. The antenna characteristicsunder different temperatures are studied in the full-wave simulation software by incorporating a temperature dependent function of the permittivity of128°YX-LiNbO3 substrate while the thermal expansion of the metallization is proved to be negligible.ResultsResultsResultsResultsSome compact SAW RFID prototypes with a folded dipole antenna within a dimension of 16mm*10mm are simulated and fabricated. A 15MHz -10dBbandwidth and a gain of -8dBi are implemented. The impedance mismatch between the antenna and the SAW RFID are also measured within the rangefrom -20°C to 100°C.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn this paper, an UHF folded dipole antenna is employed to achieve an electrically small footprint. This work has the advantages of compact size, hightemperature resistance, and easy fabrication.

Keywords:Keywords:Keywords:Keywords: SAW; RFID; fully integrated; miniaturized antennaAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11174205).


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INFLUENCEINFLUENCEINFLUENCEINFLUENCE OFOFOFOFCRACKCRACKCRACKCRACKORIENTATIONORIENTATIONORIENTATIONORIENTATIONANDANDANDAND BOUNDARYBOUNDARYBOUNDARYBOUNDARYCONDITIONSCONDITIONSCONDITIONSCONDITIONS ONONONON FRACTUREFRACTUREFRACTUREFRACTURE

BEHAVIORBEHAVIORBEHAVIORBEHAVIOROFOFOFOFPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICMATREIALSMATREIALSMATREIALSMATREIALS

Cui-ying FAN 1, Ming HAO 1,2 *, Jia-peng WANG2

1The School of Mechanical Engineering, Zhengzhou University, Zhengzhou, Henan, 450001, China2Department of Engineering Mechanics, Zhengzhou University, Zhengzhou, Henan, 450001, China


In recent years, piezoelectric materials have been widely used in many high-tech areas. Fracture is one of the major failure modes of these materials.Previous studies of piezoelectric fracture were mostly limited to cracks lying in transversely isotropic plane. In reality, however, cracks in materials andstructures could be orientated arbitrarily. Meanwhile, the influence of electric boundary conditions on fracture is rather complex. Therefore, the study ofcracks with arbitrary orientation under different boundary conditions is of great theoretical significance and application value.In this paper, an arbitrarily oriented crack in a finite two-dimensional (2D) piezoelectric medium is analyzed by using the polarization saturation (PS)model. Using the extended Green's functions corresponding to the extended point-displacement discontinuities of an arbitrarily oriented crack and thehybrid extended displacement discontinuity-fundamental solution (HEDD-FS) method, the extended field intensity factors and the local J-integral nearthe crack tip are studied for an electrically nonlinear crack under different electrical boundary conditions. The influence of the crack orientation andboundary condition on the fracture behavior is investigated.

Keywords:Keywords:Keywords:Keywords: piezoelectric material; arbitrarily oriented crack; boundary condition; PS modelAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11102186, No.11072221), theProgram for Innovative Research Team (in Science and Technology) in University of Henan Province (2010IRTSTHN013)


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ULTRAHIGHULTRAHIGHULTRAHIGHULTRAHIGHTEMPERATURETEMPERATURETEMPERATURETEMPERATURE PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICACCELEROMETERACCELEROMETERACCELEROMETERACCELEROMETER USINGUSINGUSINGUSING LANGATATELANGATATELANGATATELANGATATE

SINGLESINGLESINGLESINGLE CRYSTALSCRYSTALSCRYSTALSCRYSTALS

Pan GAO1*, Yan-qing ZHENG1, Xi LIU1, Cheng-feng YAN1, Juan XIN1, Yi-fang TU1, Er-wei SHI11 Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, P.R. China, 201800


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveHigh temperature sensors are widely used in many fields such as aerospace, automotive, energy generation, and other systems. Industrial applications ofhigh temperature sensors exist in engine health monitoring for both turbine and piston engines, in which the sensors must be able to operate reliablyunder the harsh internal environments of an engine. Extensive effort has been expended to develop high temperature sensors including thermocouples,platinum (Pt) strain gages, microelectromechanical system (MEMS), silicon carbide (SiC) sensors, and fiber optic sensors. However, they suffer fromlow sensitivity, short lifetimes, limited operational temperature ranges and/or complex packaging. Piezoelectric sensors for high temperatureapplications have attracted significant attention, offering relatively simple structures, fast response times, and easy integration. Accelerometers based onpiezoelectric materials are of interest for measuring and recording dynamic mechanical parameters including shock, stress, and vibration. However, theuse of the piezoelectric materials at elevated temperature often presents challenges in addition to the simple change in electromechanical propertiesaccording to a predictable temperature coefficient. Those challenges include: material phase transitions, which lead to large variations in theelectromechanical coefficients and can cause irreversible degradation of the material properties; increased electrical conductivity which interferes withthe detection of the piezoelectrically induced charge; and increased attenuation of acoustic waves from mechanical loss. All of these factors must beconsidered when choosing the appropriate material for a particular high temperature application.Recently, high temperature properties of piezoelectric langatate (LGT) single crystals have been attached much interesting. Thus, in this letter, a hightemperature monolithic compression-mode piezoelectric accelerometer is fabricated using LGT single crystals firstly. The performance of theaccelerometer is tested as function of temperature up to 800 °C and it shows that the LGT piezoelectric accelerometers are promising candidates forhigh temperature sensing applications.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/Methods

Figure 1. (a) As-grown LGT single crystals; (b) Schematic diagram of the monolithic compression mode accelerometersensor assembly

The LGT single crystals were grown using the Czochralski technique and this method has been widely reported. The transparent as-grown LGT singlecrystals with 3 inches were shown in Figure 1(a). Figure 1(b) shows a schematic diagram of the monolithic compression-mode accelerometer assembly,which mainly includes the preloading case, seismic mass and the piezoelectric LGT crystal transduction element.ResultsResultsResultsResults

Figure 2. Sensitivity of the LGT piezoelectric accelerometer as function of temperature up to 649°C at 160 Hz

Figure 2 shows the sensitivity of the accelerometer as a function of temperature. It was found that the LGT monolithic compression mode


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accelerometer demonstrated a sensitivity of 10 + 0.4 pC/g with little variation across the tested temperature from-200°C to 649°C.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn summary, a compression-mode accelerometer prototype based on piezoelectric single crystal LGT was designed, fabricated, and tested as a functionof temperature from -200 °C to 649 °C at 160 Hz. The sensitivity of the accelerometer was found to be 10 + 0.4 pC/g across the measured temperature.The high temperature dwell tests revealed stable behavior, thus demonstrating the potential of LGT as a material for vibration sensing in an extremeenvironment and it offers a high working temperature range up to at least 649 °C with a low temperature coefficient, high temperature stability andmoderate sensitivity.

Keywords:Keywords:Keywords:Keywords: piezoelectric accelerometer; langatate; high temperature; sensitivityAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported by the National Natural Science Foundation of China (No. 51002167) and the KnowledgeInnovation Program of the Chinese Academy of Sciences (No. KGCX-2-YW-206).


1


DESIGNDESIGNDESIGNDESIGNOFOFOFOFTEMPERATURETEMPERATURETEMPERATURETEMPERATURE SENSORSENSORSENSORSENSORARRAYARRAYARRAYARRAY ININININ SMARTSMARTSMARTSMARTELECTRICELECTRICELECTRICELECTRIC GRIDGRIDGRIDGRID BASEDBASEDBASEDBASEDONONONON SAWSAWSAWSAW

RESONATORSRESONATORSRESONATORSRESONATORS

Yu-lin HAN1, Yong-wei WANG1 , Chen-rui ZHANG1, Tao Han1*，Ji Wang21Shanghai Jiaotong University, China, People's Republic of, [email protected]

2Ningbo University*Corresponding author, E-mail: [email protected]; Tel.: 021-34204761

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveTemperature is one of the key elements to be on-line monitored to ensure the stability of smart electric grid. The equipment and devices requiringmonitoring temperature in smart grid include: the overhead line conductor and the switch contacts in high voltage switchgears in order to optimizetransmission capacity of the lines. Compared with the classical approaches of monitoring temperature online such as the infrared radiation, the opticalfiber and the wireless active sensor, the application of surface acoustic wave (SAW) sensor array is more appropriate to monitor temperature in smartgrid because of its unique characteristics-- truly passive(no need of power in sensors), naturally wireless(not affected by any kind of electrical, magneticor thermal stress that may occur during service), high voltage insulation properties and dielectric, thermal and high frequency behavior. In practice, thedistributed temperature measurement is required; but the sensor capacity in array is limited by bandwidth in the ISM band.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe complete temperature sensor consists of a SAW resonator chip, an antenna which receives and transmits the signal from and to the reader unit andan encapsulation for installation and for protection against environmental influence. Surface transverse wave (STW) resonators are adopted since STWmodes have manifested a higher intrinsic Q factor at the same central frequency over their Rayleigh wave counterparts, thus improve the resolution ofwireless SAW sensors [Fig. 1]. We use the Green’s function simulator combined with effective material constants to precisely simulate the temperaturesensitivity of STW resonator on quartz. The temperature sensitivity can be accurately controlled by the metallization thickness of the resonator so as tokeep the temperature-induced frequency shifts of each sensor within a limited bandwidth over a wide operating temperature ranging from -40°C to+150°C. The thermal parameters of sensor encapsulation are optimized according to the high voltage switchgear application. Wireless SAW sensorarray is interrogated by a frequency stepped continuous-wave signal. In the super heterodyne reader, some novel demodulation approaches are proposed.For example, we remain a fixed frequency difference of 1MHz between the interrogation and the demodulation for perfectly detecting each sensor echo.Logarithmic amplifier is also used to increase dynamic range of the receiver so as to improve resolution of frequency estimation.ResultsResultsResultsResultsThe sensor array with eight SAW resonators working at the frequency range of 429-436 MHz is designed and fabricated. The standard deviation of theestimated resonator frequency through the methods mentioned above is within 150Hz. The measurement uncertainty of the prepared SAW temperaturesensor is less than 0.5 , and the sensitivity of sensor is up to 4 kHz/, the temperature-frequency characteristic is linear in the temperature range of–40－+150.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn this paper, design of wireless temperature sensor array based on SAW resonators is introduced since SAW resonators in wireless systems are benefitfor their narrow band interrogation with an RF burst. Several high voltage tests to verify the operating characteristics and the performance areperformed. The result demonstrates that the SAW temperature sensor array is capable of stable and accurate measurement in the smart electric grid.

Keywords:Keywords:Keywords:Keywords: SAW; smart electric grid; temperature; sensor arrayAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This paper is supported by NSFC with grant No. 11174205 and the Impact and Safety of Coastal Engineering Initiative, aCOE Program of Zhejiang Provincial Government at Ningbo University (Grant No. zj1101).

Fig.Fig.Fig.Fig. 1:1:1:1: WirelessWirelessWirelessWireless SAWSAWSAWSAW TemperatureTemperatureTemperatureTemperature SensorsSensorsSensorsSensors



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THETHETHETHE BOUNDARYBOUNDARYBOUNDARYBOUNDARYCONDITIONSCONDITIONSCONDITIONSCONDITIONS OFOFOFOFTHETHETHETHE FIXEDFIXEDFIXEDFIXED ENDENDENDENDOFOFOFOF PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC CANTILEVERCANTILEVERCANTILEVERCANTILEVER

BEAMSBEAMSBEAMSBEAMS

Lian-zhi YANG1, Liang-liang Zhang1, Yang GAO1*, Min-zhong WANG2

1College of Science, China Agricultural University, Beijing 100083, China2Department of Mechanics and Aerospace Engineering, Peking University, Beijing 100871, China


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAppropriate boundary conditions are necessary to the piezoelectric beam theories otherwise the higher-order accuracy provided by the theories wouldbecome meaningless. By using the reciprocal theorem and the general solution of piezoelectricity, the concise and universal boundary conditionsaccurate to all orders have been obtained by Gao et al., in which two sets of mixed boundary conditions of stresses and displacements have been firstestablished. The pure stress boundary conditions are the same with conventional stress conditions, however, pure displacement boundary conditionshave not been obtained yet.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn this paper, the bending of piezoelectric cantilever beam was investigated. The simplified linear elastic equations of piezoelectric cantilever beamwere derived according to the characters of the problem. Using the inverse method, the stress function and the electric potential function wereestablished, and then the analytical expressions of stress, electric displacement and electric potential were obtained.Two different displacement boundary conditions of the fixed end of a cantilever beam are used to study the deformation of the beam. One is theconventional simplified displacement boundary condition, and the other is a new boundary condition determined by least squares method.ResultsResultsResultsResultsComparing with the results from the finite element method, it’s shown that the exact beam theory by using the new boundary condition provides betterresults than using the conventional boundary condition.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe new boundary condition determined by least squares method of a cantilever beam could remarkably improve the analytical solution of thepiezoelectric beam. Even though the displacement boundary condition at the fixed end is still not strictly satisfied, the solution obtained by using thenew boundary condition is an approximation closer to the reality.

Keywords:Keywords:Keywords:Keywords: cantilever beams; piezoelectric; the exact theory; least squares methodAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11172319) and Chinese UniversitiesScientific Fund (No. 2011JS046).



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AAAANOVELNOVELNOVELNOVELAPPROACHAPPROACHAPPROACHAPPROACHTOTOTOTO SIMULATESIMULATESIMULATESIMULATE LOW-LOSSLOW-LOSSLOW-LOSSLOW-LOSS SURFACESURFACESURFACESURFACEACOUSTICACOUSTICACOUSTICACOUSTICWAVEWAVEWAVEWAVE DEVICESDEVICESDEVICESDEVICES

USINGUSINGUSINGUSING DISPERSIVEDISPERSIVEDISPERSIVEDISPERSIVE COMCOMCOMCOMPARAMETERSPARAMETERSPARAMETERSPARAMETERS

Hao WANG1, Wei-biao WANG2, Bo SU1, Jian WANG3, Hao-dong WU1, Yong-an SHUI1*1Key Laboratory of Modern Acoustics (MoE), Institute of Acoustics, Nanjing University, Nanjing 210093

2The 55th Research Institute of China Electronic Technology Group Corporation, Nanjing 2100163School of Electronic Science and Engineering, Nanjing University, Nanjing 210093


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveSAW devices have been widely used as the core components of mobile communication systems. The COM model are widely used in the design oflow-loss SAW devices. Traditional COM parameters were considered as non-dispersive, but there was a considerable error when leaky SAW deviceswere simulated. Many works had been devoted to study dispersive COM parameters. The key problem of extracting dispersive parameters is that thereflection coefficient and central frequency could not be obtained independently. One way to solve the problem is to assume either one is constant [1-2].But from the physical point of view, the assumption was not proper. Although the simulation had been improved more or less, the discrepancy betweensimulation and practical behavior is still detectable.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsA novel approach is proposed to get dispersive COM parameters independently. A finite periodic grating is in consideration. Using FEM/BEM tool, thefield (mechanical displacements and electric potential) distribution could be calculated at each frequency. Then the field contributed by SAW must beseparated from the total field by Source Regeneration Method [3]. Considering both shorted and opened gratings, all the dispersive parameters wouldbe evaluated. In particular, the dispersive reflection coefficient and central frequency could be extracted independently.ResultsResultsResultsResultsAs examples, the dispersive COM parameters are extracted with various electrode thicknesses and metallization ratios. Using the parameters, a one-portresonator and a DMS filter are simulated.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsCompared with the simulation using traditional COM parameters, the results using dispersive parameters are much closer to those by FEM/BEM.Although the simulation has been improved obviously, it is still not the same as that by FEM/BEM. The difference should have reasonable explanations.The results verify this method is accurate and effective.

Keywords:Keywords:Keywords:Keywords: SAW; low-loss devices; coupling-of-modes model; dispersive COM parametersAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10774073 and No. 11174143) andthe Natural Science Foundation of Jiangsu Province (BK2010380).



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PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATIONOFOFOFOFBLEUSTEIN-GULYAEVBLEUSTEIN-GULYAEVBLEUSTEIN-GULYAEVBLEUSTEIN-GULYAEVWAVEWAVEWAVEWAVE ININININAAAA PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC CRYSTALCRYSTALCRYSTALCRYSTAL ININININ

CONTACTCONTACTCONTACTCONTACTWITHWITHWITHWITHVISCOUSVISCOUSVISCOUSVISCOUS SOLUTIONSOLUTIONSOLUTIONSOLUTION

Feng-lin GUO*, Guo-qing WANG

Department of Engineering Mechanics, Shanghai Jiaotong University, Shanghai 200240


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveAcoustic surface waves propagating in a piezoelectric crystal are extremely sensitive to changes in mechanical or electrical properties at or near thecrystal surface. This property of sensitivity has allowed the successful application of these devices as gas and liquid phase sensors.As acoustic surface waves travel in a piezoelectric crystal, they generate an evanescent RF electric field which extends into the adjacent liquid andcouples to nearby ions or dipoles (permanent or induced) in solution. This coupling effect causes ion and dipole motion, resulting in the storage anddissipation of electrical energy. Changes in stored electrical energy perturb the wave velocity, while electrical dissipation leads to attenuation. Thisphenomenon is known as acoustoelectric coupling. For liquid sensing applications, the interaction mechanisms include both the liquid viscosity andacoustoelectric coupling, which influences the wave propagation characteristics, namely velocity and attenuation.In this study we present an analysis of Bleustein-Gulyaev wave (refer to B-G wave hereinafter) propagating in a piezoelectric half space in contact withviscous solution. It is aimed to provide essential data and theoretical foundation for the design and development of this type of liquid phase sensors andbiosensors.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe propose a scheme for determining liquid viscosity and conductivity from changes of wave propagation characteristics. In the case of viscoussolution, both viscosity and acoustoelectric coupling will contribute to change of wave velocity and attenuation. It is shown that metallized condition isappropriate for viscosity sensing since the electrical properties of liquid will not come into play in this condition. After the liquid viscosity has beenknown, the open circuit condition needs to be employed, in which the electrical properties of liquid will influence the wave propagation characteristics.From that the liquid conductivity can be calculated.The dispersion relations are derived for B-G wave propagating in a hexagonal piezoelectric crystal in contact with viscous solution in both metallizedand open circuit interface conditions. These relations are essential for the determination of liquid properties from measured wave propagationcharacteristics.ResultsResultsResultsResultsNumerical results are obtained for B-G wave propagating in a PZT-5H half space in contact with viscous solution. Variations of wave velocity andattenuation with liquid viscosity and conductivity for both metallized and open circuit solid-liquid interface conditions are presented in the form offigures. These results show that the attenuation increases with the increase of liquid viscosity and conductivity. Changes of liquid viscosity andconductivity have larger effect on attenuation than wave velocity. It is also observed that attenuation increases with increase of wave frequency.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIn this study we have described the sensing principle of a liquid-phase sensor using B-G wave in piezoelectric crystals. Explicit dispersion relations arederived for both the metallized and open circuit interface conditions. It is found that acoustoelectric coupling and viscosity significantly affect acousticwave propagation properties at a solid/liquid interface. We demonstrate, from the theoretical point of view, that liquid properties can be determinedfrom measured wave propagation characteristics by employing proper inversion algorithms.

Keywords:Keywords:Keywords:Keywords: Bleustein-Gulyaev wave; liquid sensing; acoustoelectric coupling; dispersion relationsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Grant Nos. 10472068 and 11272206).



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HIGH-EFFICIENTHIGH-EFFICIENTHIGH-EFFICIENTHIGH-EFFICIENT BROADBANDBROADBANDBROADBANDBROADBAND LAMBLAMBLAMBLAMBWAVEWAVEWAVEWAVE RECTIFIERRECTIFIERRECTIFIERRECTIFIER BASEDBASEDBASEDBASEDONONONONAAAAONE-DIMENSIONALONE-DIMENSIONALONE-DIMENSIONALONE-DIMENSIONALGRADEDGRADEDGRADEDGRADED PHONONICPHONONICPHONONICPHONONIC CRYSTALCRYSTALCRYSTALCRYSTALSLABSSLABSSLABSSLABS

Jiu-jiu CHEN*, Xu HANState Key Laboratory of Advanced Design and Manufacturing for Vehicle Body,

College of Mechanics and Vehicle Engineering, Hunan University, Changsha, 410082, P.R. China

*Corresponding author, E-mail: [email protected]

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUsually, waves can travel just as easily in either direction along a given path. The invention of electric diode, which acts as a one-way filter for thecurrent flux, has marked the beginning of modern electronics and eventually led to worldwide revolutions in many aspects. Similar devices also existfor light and heat transmission. However, it is much more difficult to make such one-way devices for sound waves, another important form of classicalwave with even longer research history than electric waves, because of the way sound waves move though a material.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe result is obtained by the eigenmode matching theory method and finite element methodResultsResultsResultsResultsThe unidirectional transmission of Lamb wave is realized by a one-dimensional graded phononic crystal slabs.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIt stems from the threshold frequency of the fundamental antisymmetric Lamb mode conversion to the fundamental symmetric Lamb mode is different inlow-frequency domain at the different locations of the diode. A tunable Lamb wave diode is also achieved by changing the grade of the grating depths.Such shaped graded materials can serve as good candidates for acoustic rectification.

Keywords:Keywords:Keywords:Keywords: lamb wave; graded phononic crystal slabs; rectifierAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported by NSFC (Grant No. 10902035).


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COMPUTATIONALCOMPUTATIONALCOMPUTATIONALCOMPUTATIONALANALYSISANALYSISANALYSISANALYSIS ONONONONTHETHETHETHE DRAGDRAGDRAGDRAG FORCESFORCESFORCESFORCES OFOFOFOFOIL-PIPELINESOIL-PIPELINESOIL-PIPELINESOIL-PIPELINES ININININ DRILLINGDRILLINGDRILLINGDRILLINGACROSSACROSSACROSSACROSSYELLOWYELLOWYELLOWYELLOWRIVERRIVERRIVERRIVER

Shi-qi XU1, Bin LUO2, Jun CHEN2, Hong-ping HU2, Yuan-tai HU2*

1College of Petroleum Engineering, Xi'an Shiyou University, Xi'an 7100652Department of Mechanics, Huazhong University of Science and Technology,Wuhan 430074


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThis paper reviewed the methods, which calculate the pull strength during directional drilling crossing construction of oil pipeline.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsBased on the analysis of these methods, the detailed research of application conditions was given. At the same time, considering the peculiarity of thischannel geologic structure and the technological requirements.ResultsResultsResultsResultsThe method, averaged standard method and unloading arch method, was given to calculate the maximal pull strength.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIt is practiced that, the calculation result of this method is close to the actual result, which is instructive and meaningful to the directional drillingcrossing construction.

Keywords:Keywords:Keywords:Keywords: directional drilling crossing; pull strength; pipeline laying



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THETHETHETHE STUDYSTUDYSTUDYSTUDYOFOFOFOFHIGH-FREQUENCYHIGH-FREQUENCYHIGH-FREQUENCYHIGH-FREQUENCYBROAD-BANDBROAD-BANDBROAD-BANDBROAD-BAND UNDERWATERUNDERWATERUNDERWATERUNDERWATERTRANSDUCERSTRANSDUCERSTRANSDUCERSTRANSDUCERS

Kai ZHANG, Qing HU, Hong MENG, Yang-wei CHEN *

Hangzhou Applied Acoustics Research Institute, Hangzhou 310012*Kai ZHANG, E-mail: [email protected]; Tel.: 0571-56782260

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveBroadband transducers have much advantage in signal transmission, such as reducing of signal distortion, widening the security about informationtransmission, reducing the ratio of false codes. But there are some difficulties to make high-frequency transducer as the broadband transducer. Becausethe mechanical size of transducer is usually inversely proportional to the resonance frequency, and the expanding bandwidth method of middle or lowfrequency transducer is difficult to apply to the high-frequency transducer.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe working principle of the transducer is the combine of the piezoelectric pillars and dual matching layer. The electromechanical coupling coefficientof the piezoelectric pillar is better than piezoelectric plate, and it makes the bandwidth of pillar transducer wider. The combine of the piezoelectricpillars and dual matching layer can further expand the bandwidth of the high-frequency transducer. The structure of this transducer provides ahigh-frequency transducer to achieve wideband emission method. The finite element model of the transducer is set up by ANSYS. The structure of thetransducer was optimized with the above method.ResultsResultsResultsResultsAn underwater transducer was designed, which used the first thickness mode, the second thickness mode and the third thickness mode. The bandwidthof the transducer is 47 kHz-157 kHz, in which the ripple of the transmitting voltage response does not exceed ±1.5dB.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThere are several conclusions from the research: the bandwidth of matching layer transducers can be expanded by the first thickness mode, the secondthickness mode and the third thickness mode, and it gives a method to achieve the broad-band projecting performance of high-frequency transducers.

Keywords:Keywords:Keywords:Keywords: underwater transducer; high-frequency; finite element method



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DAMAGEDAMAGEDAMAGEDAMAGE IDENTIFICATIONIDENTIFICATIONIDENTIFICATIONIDENTIFICATION ININININAAAA STEELSTEELSTEELSTEELFRAMEFRAMEFRAMEFRAMEUSINGUSINGUSINGUSING ELECTRO-MECHANICALELECTRO-MECHANICALELECTRO-MECHANICALELECTRO-MECHANICAL

IMPEDANCEIMPEDANCEIMPEDANCEIMPEDANCE SIGNATURESSIGNATURESSIGNATURESSIGNATURES

Wei WANG1, Wei YAN1*, Ji WANG2

1 Faculty of Architectural, Civil Engineering and Environment, Ningbo University, Ningbo 315211

2 Faculty of Mechanical Engineering and Mechanics, Ningbo University, Ningbo 315211


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe structural bearing capacity may generally decline when the damages are introduced into the structure components and their connections. In manycases, the whole structures may collapse due to the connection damages especially for the frame structures. So, in order to avoid such unfortunatesituations, early detection for the joint damages of the frame structures is very necessary. EMI (Electro-mechanical impedance) technology is a typicalapplication of the electro-mechanical coupling effect of piezoelectric material in the field of structural health monitoring. Because the EMI signaturesare obtained in the high-frequency range, this method is able to detect the minor and early damages in the structures. Through monitoring the measuredelectro-mechanical impedance and comparing it to a baseline measurement, we can qualitatively determine that structural damages have occurred orhave extended.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsDamages are introduced by completely loosening bolts over several locations on the steel frame. Experimental data are then analyzed by the damageindex RMSD (Root mean square deviation) to identify the damage severities and locations qualitatively.ResultsResultsResultsResultsExperimental studies show that high-frequency EMI signatures can identify structural damage severity and damage location effectively, and theintegrated method combining the EMI technique and the damage index RMSD can be used reliably for structural health monitoring.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsA steel frame with bolt damages is investigated by the EMI method. The damage index (RMSD) is introduced to process the obtained electricadmittance signatures. According to experimental data and analytical results, the present technology can effectively identify the damage severities anddamage locations. It may provide a reliable and effective method to detect damages for the similar structures.

Keywords:Keywords:Keywords:Keywords: EMI; structural health monitoring; steel frame; RMSDAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported in part by grants from the National Natural Science Foundation of China (Nos. 10932004),Zhejiang Provincial Natural Science Foundation of China (No. LY12E08005) and the program of Key Team of Technological Innovation of ZhejiangProvince (No. 2011R09025-03).


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AAAA PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRIC UNIMORPHUNIMORPHUNIMORPHUNIMORPH POWERPOWERPOWERPOWERHARVESTERHARVESTERHARVESTERHARVESTEROPERATINGOPERATINGOPERATINGOPERATINGWITHWITHWITHWITHCOUPLEDCOUPLEDCOUPLEDCOUPLED

EXTENSIONEXTENSIONEXTENSIONEXTENSIONANDANDANDAND FLEXUREFLEXUREFLEXUREFLEXUREMODESMODESMODESMODES

Zi-yang LIAN 1 , Lin HU1 , Jun CHENG1, Hong-ping HU 1* , Yuan-tai HU1, Ji WANG2

1Department of Mechanics, Huazhong University of Science and Technology,Wuhan 4300742 Piezoelectric Device Laboratory, Department of Mechanics and Engineering Science, School of Mechanical Engineering and Mechanics, Ningbo University, Ningbo, 315211

* Corresponding author, E-mail: [email protected] ; Tel.: 027-87559409

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveWith the development of microelectronics and wireless sensor network, their energy supply has become an urgent issue to solve. The microelectronicsis often away from a fixed power, especial for portable or implantable electronics. It is necessary to be supplied energy wirelessly. However, traditionalbattery supply energy technique cannot meet the demand of the energy supply, due to high ratio of weight to energy. It is a tedious job to replace thebatteries for hundreds of thousands nodes of wireless sensor network. Extracting energy from operating environment of electronics is a viable methodfor supply energy wirelessly. Vibration and noise exists extensively. Piezoelectric materials become natural candidates to design energy harvesterwhich can convert the mechanical energy to electrical energy efficiently. Piezoelectric power harvester (PWH) has inspired a great deal of researchinterest.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsWe have set up a model of a piezoelectric unimorph power harvester (PUPH). The PUPH consists of a piezoelectric layer and a metal layer. One end ofthe PUPH is fixed on a vibration base, the other end is connected by a concentrated mass. The PUPH is inclined mounting with an angle between itsaxis and the horizontal direction. The PUPH scavenges energy from coupled extension and flexure vibration. We present a theoretical analysis on thebasic behaviors of the PUPH by the theory of linear piezoelectricity.ResultsResultsResultsResultsThe solutions for coupling extension and flexure motion of the PUPH have been obtained. Base on these solutions, we have gotten the curves fordependence of performance of the PUPH on inclined install angle, physical and structure parameters.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe inclined mounting piezoelectric unimorph proposed can operate as a harvester to scavenge energy from vibration environment. The performance ofthe PUPH has been optimized by adjusting the inclined angle, the physical and geometrical parameters of the structure.

Keywords:Keywords:Keywords:Keywords: piezoelectric power harvester; unimorph; coupling vibrationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This work was supported by the National Science Foundation of China (11272126, 10932004), 973 Program(2009CB724205), Research Fund for the Doctoral Program of Higher Education of China (20110142120050), Fundamental Research Funds for theCentral Universities (2011QN184), and Open Fund of the most important disciplines of Zhejiang Province on offshore impact and safety engineering(zj1115).



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PROPAGATIONPROPAGATIONPROPAGATIONPROPAGATIONOFOFOFOFSHSHSHSH SURFACESURFACESURFACESURFACEWAVESWAVESWAVESWAVES ININININAAAA SEMI-INFINITESEMI-INFINITESEMI-INFINITESEMI-INFINITE

MAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTICMAGNETO-ELECTRO-ELASTIC LAYEREDLAYEREDLAYEREDLAYERED PERIODICPERIODICPERIODICPERIODIC STRUCTURESSTRUCTURESSTRUCTURESSTRUCTURES

Yu PANG*, Zhen-hua SUN, Jin-xi LIU

Department of Engineering Mechanics, Shijiazhuang Tie Dao University, Shijiazhuang ,050043


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjective

In this paper, propagation of shear horizontal (SH) surface waves in a semi-infinite magneto-electro-elastic layered periodic structure is investigated.

StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsThe dispersion equations are derived for SH surface waves in a semi-infinite piezoelectric/elastic/piezomagnetic layered periodic structures by thetransfer matrix method with free surface parallel to the layers. The piezoelectric and piezomagnetic materials are assumed to be transversely isotropic.The dispersion curves are plotted for SH surface waves considering two cases of unit cell arrangement: one is piezoelectric/elastic/piezomagnetic andthe other is piezomagnetic/elastic/piezoelectric. Four kinds of electric-magnetic boundary conditions at the free surface on dispersion curves for SHsurface waves are discussed in detail. For comparison, the band structures of SH bulk waves in infinite periodic structures for these two cases arepresented.

ResultsResultsResultsResultsNumerical examples are presented for PZT-5H/Polymer/CoFe2O4 and CoFe2O4/Polymer/PZT-5H infinite/semi-infinite layered periodic structures.Results show that the dispersion curves of SH surface waves are below the bulk bands or inside the frequency gaps.

DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe frequency band structures for SH bulk waves are consistent for these two infinite periodic structures. The electric/magnetic open and shortconditions for PZT-5H/Polymer/CoFe2O4 and CoFe2O4/Polymer/PZT-5H structures have obvious/little effects on dispersion curves for SH surfacewaves, respectively.

Keywords:Keywords:Keywords:Keywords: SH surface wave; magneto-electro-elastic; layered periodic structures; dispersion curves

Acknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (Nos. 11102122, 10972147 ) and theProgram for Changjiang Scholars and Innovative Research Team in University (No.IRT0971).


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EFFECTSEFFECTSEFFECTSEFFECTS OFOFOFOFBOUNDARY-LAYERBOUNDARY-LAYERBOUNDARY-LAYERBOUNDARY-LAYERTHICKNESSTHICKNESSTHICKNESSTHICKNESS ONONONONAERO-ACOUSTICSAERO-ACOUSTICSAERO-ACOUSTICSAERO-ACOUSTICS CHARACTERISTICSCHARACTERISTICSCHARACTERISTICSCHARACTERISTICS

OFOFOFOFSUBSONICSUBSONICSUBSONICSUBSONIC SHALLOWSHALLOWSHALLOWSHALLOWCAVITYCAVITYCAVITYCAVITYFLOWFLOWFLOWFLOW

Dang-guo YANG1, 2, Jian-qiang LI2 , Jin-min LIANG2 , Yao-hua LI 2, Jun LIU 2, 3

1State Key Laboratory of Aerodynamics, China Aerodynamics Research and Development Center, Mianyang Sichuan 621000, China2High Speed Aerodynamics Research Institute, China Aerodynamics Research and Development Center, Mianyang Sichuan 621000, China

3School of Aerospace, Tsinghua University, Beijing 100084*Corresponding author, E-mail: [email protected]; Tel.: 0816-2462267

Abstract:Abstract:Abstract:Abstract:High-speed flows in cavities such as grooves, wheel wells, and weapon bays, are often encountered in aerospace and aeronautical vehicles. In mostcases the flow field is complex and unsteady, featured by shear-layer instability, flow separation and formation of vortex structures, shockwave/boundary-layer interactions at transonic and supersonic speeds. Complex unsteady flow characteristics occur therein, such as fluctuating pressureand velocity. Some aerodynamic noise inside the cavity can reach 170dB, which can damage some installed apparatus inside the cavity and structuralcomponents of the cavity. This paper presents that sound pressure level (SPL) distributions and sound pressure frequency spectrum (SPFS)characteristics at different measurement positions on cavity floor centerline utilizing two terms of experimental results under experimental conditions.Effects of different free-stream boundary-layer thickness to cavity depth ratios on shallow cavities (transitional and closed cavity flow) were discussed.The data presented herein was obtained about the cavities with length to depth ratios of 12 and 15 over a Mach number of 0.6 at a Reynolds number of1.23×107 per meter. The results show that decrease in the boundary-layer thickness to the cavity depth ratios (δ/D) causes SPL amplification and noiseenhancement at different measurement positions inside the cavities, especially the front and middle. Moreover, decrease in δ/D has a significantinfluence on SPFS characteristics and leads to increase in SPL in the frequency range of 0Hz＜f＜1000Hz at subsonic speeds (Ma=0.6).

Keywords:Keywords:Keywords:Keywords: boundary layer thickness; shallow cavities; aero-acoustic characteristics; subsonic speeds; sound pressure level (SPL); sound pressurefrequency spectrum (SPFS)

Acknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National 973 Project Foundation of China (No. 2009CB7238026) and National 863Project Foundation of China (No. 2007AA04Z129). Professor Zhao-lin FAN in China Aerodynamics Research and Development Center provides somegood and useful suggestions to the paper.



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INVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATIONONONONON PARAMETERSPARAMETERSPARAMETERSPARAMETERS INFLUENCINGINFLUENCINGINFLUENCINGINFLUENCING SYNTHETIC-JETSYNTHETIC-JETSYNTHETIC-JETSYNTHETIC-JET FORFORFORFORACTIVEACTIVEACTIVEACTIVE FLOWFLOWFLOWFLOW

CONTROLCONTROLCONTROLCONTROL

Yi ZHANG2, Yao-hua LI2 , Dang-guo YANG1, 2, Jun LIU2, 3, Jin-min LIANG2

1State Key Laboratory of Aerodynamics, China Aerodynamics Research and Development Center, Mianyang Sichuan 621000, China2High Speed Aerodynamics Research Institute, China Aerodynamics Research and Development Center, Mianyang Sichuan 621000, China

3School of Aerospace, Tsinghua University, Beijing 100084*Corresponding author, E-mail: [email protected]; Tel.: 0816-2462267

Abstract:Abstract:Abstract:Abstract:Synthetic-Jet technique is a novel method for flow controlling in aerodynamic characteristics of aircrafts. With science and technology’s development,flow controlling method based on Synthetic-Jet technique has significant progress, and it is very useful. The Synthetic-Jet devices become small ormicro-jet and convenience. Therefore, based on the two-dimensional structured dynamic mesh arithmetic utilizing divided mesh region, numericalsimulation on effects of parameters influencing Synthetic-Jet (SJ) on its flow characteristics and flow flied is performed in this paper. The resultsindicate that the maximum jet velocity increases as the vibration frequency and amplitude of SJ increase, and decreases as the jet outlet diameterincreases. The jet outlet height has little influence on the maximum velocity. Synthetic-jet flow presents turbulent characteristics at high Reynoldsnumber (Re), and Re increase induces vortex’s diameter and attenuation speed increase. Strouhal number (St) increase causes vortex’s diameterdecrease.

Keywords:Keywords:Keywords:Keywords: synthetic jet; active flow control; structural dynamic mesh; influencing parameters; numerical simulationAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 10972233 and 11272335). ProfessorJian-qiang LI and professor Xian-xu YUAN in China Aerodynamics Research and Development Center provides some good and useful suggestions tothe paper.



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INVESTIGATIONINVESTIGATIONINVESTIGATIONINVESTIGATIONONONONONCALIBRATIONCALIBRATIONCALIBRATIONCALIBRATIONMETHODSMETHODSMETHODSMETHODS OFOFOFOF THERMALTHERMALTHERMALTHERMALMEMSMEMSMEMSMEMS SHEARSHEARSHEARSHEAR STRESSSTRESSSTRESSSTRESSSENSORSENSORSENSORSENSORARRAYARRAYARRAYARRAY

Jin-min LIANG2, Dang-guo YANG1, 2, Jian-qiang LI2, Wei-min JIANG2

1State Key Laboratory of Aerodynamics, China Aerodynamics Research and Development Center, Mianyang Sichuan 621000, China

2High Speed Aerodynamics Research Institute, China Aerodynamics Research and Development Center, Mianyang Sichuan 621000, China


Abstract:Abstract:Abstract:Abstract:Accurate measurement of wall shear stress is very important for understanding wall bounded shear flows properly, because it provides significant

information about the flow phenomena, including viscous drag, the position where the flow transits to turbulence or separates from the model. Current

measurement of shear stresses based on traditional fabrication technology are much too bulky to accomplish the task perfectly and may destroy the

research matrix surface and most likely impossible to be used in any large-scale integration. The conflict between sensor size and sensitivity is the

maximal impedance to the advancement. So making the sensor smaller flexible with high time resolution can bring the boundary layer research to a

new horizon. One way of achieving these requirements is micro-fabricated sensors. By taking advantage of MEMS fabrication techniques, sensors can

response very quickly to the fluctuations in the flow and do not destroy the model surface. Then, combining an integrating technology, plenty of sensors

can be integrated to a membrane for measuring the wall shear stress in larger area simultaneously. The characterization of a MEMS based thermal shear

stress sensor array for high speed flow is presented in this paper. The static responses for different overheat ratios were obtained via a fully developed

duct flow with Ma number 0.1~0.6, and the influence of temperature to the sensor output voltage was measured using a heater with four resistance coils

which is able to change the flow temperature of the test section from 289~313K. The relationship between the output voltage and shear stress at

overheat ratio of 1.2 is calculated.

Keywords:Keywords:Keywords:Keywords: MEMS; shear stress sensor; calibration; flow measurement; high-speed wind tunnel

Acknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: The work was supported by the National Natural Science Foundation of China (No. 11272335 and 10972233). ProfessorBin-he MA in Northwestern Polytechnical University and Professor Ming XIAO in Nanjing University of Aeronautics and Astronautics provide some

good and useful suggestions to the paper.



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DYNAMICALDYNAMICALDYNAMICALDYNAMICALCHARACTERISTICSCHARACTERISTICSCHARACTERISTICSCHARACTERISTICS RESEARCHRESEARCHRESEARCHRESEARCHONONONONTHETHETHETHE SQUEEZEDSQUEEZEDSQUEEZEDSQUEEZED FILMFILMFILMFILMDAMPERDAMPERDAMPERDAMPER

STIFFNESSSTIFFNESSSTIFFNESSSTIFFNESS ROTORROTORROTORROTOR

Rui-hua ZHANG1,2*, Yin-fa ZHU1, Zhi-wen XIONG2, Yan-hui YE2

1 Institute of Technology, Lishui University, Lishui 323000, China2School of Mechanical and Electrical Engineering, Nanchang University, Nanchang 330031, China

*Corresponding author, [email protected]; Tel.: 86-15157817906

Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveThe Squeeze Film Damper (SFD) is the most effective and most economic elastic damping device. It has the advantages of simple structure, workingreliably and decreasing vibration of system effectively in a large range of rotating speed through adjusting damping in wide range. Truly revealingdamping mechanism of CFD-rotor system can provide a theoretical basis for optimization of design of CFD, and make it more widely used inengineering practice.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsIn order to more truly reveal damping mechanism of CFD-rotor system, impact factors and parameters of film inertia force are considered in theequations of motion of the rotor system. It developed the kinematical model of squeezed film damper (SFD) stiffness rotor system based on the inertiaparameter σ and bearing parameter B, then theoretically analyzed the amplitude-frequency characteristics and the transmission ratio characteristics ofrotor system influenced with inertia parameter σ , bearing parameter , and mass eccentricity ratio U.ResultsResultsResultsResultsThe analyzed results proved that inertia parameter σ , bearing parameter B, and mass eccentricity ratio U have large influence on theamplitude-frequency characteristics and the transmission ratio characteristics. When B is too large, it will lead to delay of self-centering, and thedamper cannot decrease vibration effectively. When B is 0.01, U is 0.3 and σ is less than 30, the damper can work efficiently, eccentricity ratio andpassing rate increase as σ increase, and the critical speed moves to the right. When σ is 30, the film damper appears in the CFD. So, when B and Uare reasonable, eccentricity ratio ε and passing rate T increase as σ increase, and the critical speed moves to the right.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsThe damping effect of CFD not only is related to unbalanced values, but also the selection of bearing parameters. The damping effect of CFD isinfluenced by inertia parameterσ , bearing parameter B, and mass eccentricity ratio U. Only with correct design of geometric parameters of the bearingsupport and working in certain condition, CFD can decrease vibration effectively. Otherwise it will make rotor system produce continuous self-excitedvibration and even make deterioration on the vibration of rotor system.

Keywords:Keywords:Keywords:Keywords: branch of mechanical engineering; squeezed film damper; inertia parameter; kinematicsAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported by NSFC (Grant No. 50965014) and Jiangxi Natural Science Fund (Grant No. 2010GZC0121).


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APPLICATIONAPPLICATIONAPPLICATIONAPPLICATIONOFOFOFOF PIEZOELECTRICPIEZOELECTRICPIEZOELECTRICPIEZOELECTRICMATERIALMATERIALMATERIALMATERIAL ININININ THETHETHETHEACTIVEACTIVEACTIVEACTIVE VIBRATIONVIBRATIONVIBRATIONVIBRATION CONTROLCONTROLCONTROLCONTROLOFOFOFOF

CONICALCONICALCONICALCONICAL SHELLSHELLSHELLSHELL STRUCTURESSTRUCTURESSTRUCTURESSTRUCTURES

Feng-ming LI1*, Zhi-guang SONG2

1College of Mechanical Engineering, Beijing University of Technology, Beijing, P.R. China, 1001242School of Astronautics, Harbin Institute of Technology, Harbin, P.R. China, 150001


Background,Background,Background,Background, MotivationMotivationMotivationMotivation andandandand ObjectiveObjectiveObjectiveObjectiveUp to now, the piezoelectric materials have been used by many researchers to study the active vibration control of beams, plates and cylindrical shells.To our best knowledge, however, few people have investigated the active vibration control of conical shells using the piezoelectric materials, whichinspires our present research. The active vibration control of conical shells is studied using the piezoelectric materials. The forced vibration responsesof the conical shell with piezoelectric patches are calculated to study the active vibration control and the influences of several parameters on the controlresults are analyzed.StatementStatementStatementStatement ofofofof Contribution/MethodsContribution/MethodsContribution/MethodsContribution/MethodsNormally, in the equation of motion of the conical shells, some coefficients are variables, which makes the equation of motion of the conical shells verycomplicated and difficult to be solved analytically. In order to solve this problem, Hamilton’s principle with the assumed mode method is employed toderive the equation of motion of the complex electromechanical coupling system. The active vibration control of conical shells is studied using velocityfeedback and linear quadratic regulator (LQR) methods. The optimal design for the locations of the piezoelectric patches is also developed by thegenetic algorithm. Based on the traditional theory of structural dynamics, this method is easy to understand and verified by numerical simulations.ResultsResultsResultsResultsFrom the numerical results it can be seen that the control gain has significant effect on the vibration control of the conical shell, but the effect of the sizeof the piezoelectric patches on controlling the vibration amplitudes is not so obvious. Moreover, the optimal placement scheme of the piezoelectricpatches obtained by the genetic algorithm can significantly reduce the vibration amplitudes of the conical shell.DiscussionDiscussionDiscussionDiscussion andandandand ConclusionsConclusionsConclusionsConclusionsIt is more economic to suppress the vibration level in low frequency regions by means of the active vibration control method. The overall vibration ofthe conical shell can be effectively reduced by the velocity feedback control. With the increase of the control gain, the active damping characteristics ofthe conical shell are improved.

Keywords:Keywords:Keywords:Keywords: conical shell; piezoelectric material; active vibration control; LQR; velocity feedback controlAcknowledgements:Acknowledgements:Acknowledgements:Acknowledgements: This research is supported by NSFC (Grant No. 11172084, 11002045, 10672017) and National Basic Research Programof China (No. 2011CB711100).


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AuthorAuthorAuthorAuthor IndexIndexIndexIndex

AAAA

Zhi-wu AN Paper No.: 51

BBBB

Lin-lang BAI Paper No.: 39

Gang BAO Paper No.: 108

CCCC

Da-guo CAI Paper No.: 78

Fei-yan CAI Paper No.: 53

W.Y. CHANG Paper No.: 16

M.K. CHAO Paper No.: 16

C.H. CHEN Paper No.: 17

Chao CHEN Paper No.: 50,58

De-sheng CHEN Paper No.: 60

Gen CHEN Paper No.: 120

Gui-jia CHEN Paper No.: 94,145,146

Hao CHEN Paper No.: 110,111,124

Hong-hai CHEN Paper No.: 141

Hong-juan CHEN Paper No.: 133,134

Jian-jun CHEN Paper No.: 104,107

Jiu-jiu CHEN Paper No.: 169

Jun CHEN Paper No.: 171

Qiu-ying CHEN Paper No.: 77

Shi-jin CHEN Paper No.: 148

Song-mao CHEN Paper No.: 29,32

Wei-shan CHEN Paper No.: 20,23

Xin-yi CHEN Paper No.: 41

Yang-wei CHEN Paper No.: 172

You-hua CHEN Paper No.: 92

Yuan-yuan CHEN Paper No.: 92

Zhi-gang CHEN Paper No.: 14

Jun CHENG Paper No.: 175

Kai CHENG Paper No.: 148

Ting-hai CHENG Paper No.: 108

J.S CHUANG Paper No.: 16

Jian-sheng CONG Paper No.: 77

Jing CUI Paper No.: 42

Su-xian CUI Paper No.: 104,152

DDDD

Hong-liang DAI Paper No.: 46

Kao-shan DAI Paper No.: 123,128,138

Xiang-hua DAI Paper No.: 136

Ming-kai DENG Paper No.: 112

Hao-wen DONG Paper No.: 25

Jian-ke DU Paper No.: 42,49,52,68,73,105,117,135,145,146

Xiu-lan DUAN Paper No.: 118

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Cui-ying FAN Paper No.: 160

Peng FANG Paper No.: 48

Jia-he FU Paper No.: 88

Lin FU Paper No.: 126

Sang-di FU Paper No.: 18

GGGG

C. F. GAO Paper No.: 153

Chun-hua GAO Paper No.: 14,91

Cun-fa GAO Paper No.: 136

Han GAO Paper No.: 108

Pan GAO Paper No.: 162

Qun GAO Paper No.: 85

Yang GAO Paper No.: 164

Hong-liang GU Paper No.: 115

Feng-lin GUO Paper No.: 166

Xiang-dong GUO Paper No.: 108

HHHH

H. Brito-Santana Paper No.: 83

Tao HAN Paper No.: 159,163

Xu HAN Paper No.: 169

Yu-lin HAN Paper No.: 163

Ming HAO Paper No.: 160

Zhen-hong HAO Paper No.: 13

Bin HE Paper No.: 44,97,105

Hui-jing HE Paper No.: 149

Shi-tang HE Paper No.: 11


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Xiao HE Paper No.: 110,111,124

Peng-fei HOU Paper No.: 103

Geng-kai HU Paper No.: 21

Hong-ping HU Paper No.: 171,175

Jun-hui HU Paper No.: 24,26,27,29,30,31,32

Lin HU Paper No.: 175

Qing HU Paper No.: 172

Yuan-tai HU Paper No.: 171,175

Zhen-dong HU Paper No.: 95

De-jin HUANG Paper No.: 41,59

Wei-qing HUANG Paper No.: 69,70

Xiao-di HUANG Paper No.: 60

Xin-you HUANG Paper No.: 14,91

Yi-hua HUANG Paper No.: 149

Zhen-yu HUANG Paper No.: 85,87

Ding HUI Paper No.: 148

JJJJ

Bin JIA Paper No.: 58

Hai-yang JIANG Paper No.: 103

Ji-qing JIANG Paper No.: 98

Lei JIANG Paper No.: 60

Quan JIANG Paper No.: 121,122

Wei-min JIANG Paper No.: 181

Xiang-quan JIAO Paper No.: 80

Feng JIN Paper No.: 137

KKKK

Hai-kuan KONG Paper No.: 104

Yan-ping KONG Paper No.: 72,96

LLLL

C.S. LAM Paper No.: 16,17

Ming-xuan LI Paper No.: 51

Chang-zheng LI Paper No.: 15

Cui-ping LI Paper No.: 131

Feng-ming LI Paper No.: 140,185

Guang-lin LI Paper No.: 48

Hong-lang LI Paper No.: 11

Hua-qing LI Paper No.: 26,27,31

Jian-qiang LI Paper No.: 178,181Li LI Paper No.: 71

Li-jun LI Paper No.: 89

Li-ping LI Paper No.: 78

Nan-song LI Paper No.: 65Ning LI Paper No.: 26,27,31Peng LI Paper No.: 137Qi LI Paper No.: 133,134

Xiao-niu LI Paper No.: 28

Xi-qiang LI Paper No.: 110

Yao-hua LI Paper No.: 178,180

Zhi-qiang LI Paper No.: 64

Guo-xuan LIAN Paper No.: 51

Zi-yang LIAN Paper No.: 175

Jin-min LIANG Paper No.: 178,180,181

Yong LIANG Paper No.: 11

Yu LIANG Paper No.: 70

Zhao-feng LIANG Paper No.: 81

Zhu LIANG Paper No.: 116

T.LIN Paper No.: 16

Song LING Paper No.: 123

Duo LIU Paper No.: 159

Hai-li LIU Paper No.: 85,87

Hui-sheng LIU Paper No.: 33

Jin-xi LIU Paper No.: 72,96,177

Jun LIU Paper No.: 178,180

Jun-kao LIU Paper No.: 23

Lei LIU Paper No.: 125,153

Wei-hua LIU Paper No.: 62,70

Xi LIU Paper No.: 162

Xi-en LIU Paper No.: 141

Ying-xiang LIU Paper No.: 20,23

Yong-ping LIU Paper No.: 64

Xiao-long LU Paper No.: 24

Bin LUO Paper No.: 171

Hao-Su LUO Paper No.: 116,119

Tian-li LUO Paper No.: 87

Xin-yi LUO Paper No.: 59

MMMM

Ting-feng MA Paper No.: 42,52,68,117,124,145,146

Han-ling MAO Paper No.: 88

Jie MAO Paper No.: 51

Yi-wei MAO Paper No.: 107


- 140 -

Hong MENG Paper No.: 172

Xi-ping MO Paper No.: 33,64,81

Ya-xiao MO Paper No.: 71

OOOO

Wen-chu OU Paper No.: 18

PPPP

Li PAN Paper No.: 14

Q.Q. PAN Paper No.: 16

Song PAN Paper No.: 62

Yao-zong PAN Paper No.: 64

Yong-dong PAN Paper No.: 120,123,128,125,138

Yu PANG Paper No.: 177

S.Y. PAO Paper No.: 16

Sheng-chun PIAO Paper No.: 65,71

QQQQ

Dong-hai QIAO Paper No.: 13

Bo QIN Paper No.: 158

RRRR

R. Rodríguez-Ramos Paper No.: 83

Bo REN Paper No.: 116

Hui-ling REN Paper No.: 112

SSSS

Er-wei SHI Paper No.: 104,113,152,162

Fang-fang SHI Paper No.: 15

Wei-jia SHI Paper No.: 54

Yu SHI Paper No.: 78,80

Zhi-fei SHI Paper No.: 56,76

Yong-an SHUI Paper No.: 165

Hai-yan SONG Paper No.: 65

Xue-hang SONG Paper No.: 128

Zhi-guang SONG Paper No.: 185

Bo SU Paper No.: 165

Hai-jing SU Paper No.: 21

Lin SU Paper No.: 131

P.Y. SU Paper No.: 17

Xiao-xing SU Paper No.: 25

Jing SUN Paper No.: 29,32

Zhen-hua SUN Paper No.: 177

Zhi-feng SUN Paper No.: 141

Zhi-qun SUO Paper No.: 13

TTTT

Ruo-meng TIAN Paper No.: 72,96

Jie TONG Paper No.: 103

Xiao-niu TU Paper No.: 104,113

Yi-fang TU Paper No.: 113,162

WWWW

Bao-lin WANG Paper No.: 43

Dong WANG Paper No.: 126

Guo-qing WANG Paper No.: 166

Hai-bin WANG Paper No.: 60

Hao WANG Paper No.: 165

Hua-lei WANG Paper No.: 78

Hui-ming WANG Paper No.: 55,57

Ji WANG Paper No.: 41,42,49,52,59,68,73,

84,94,109,118,135,145,

146,174,175

Jian WANG Paper No.: 165

Jia-peng WANG Paper No.: 160

Jie WANG Paper No.: 115,139

Jun-shan WANG Paper No.: 58

Li-fu WANG Paper No.: 92

Min-zhong WANG Paper No.: 164

Wei WANG Paper No.: 119,174

Wei-biao WANG Paper No.: 165

Wen-jun WANG Paper No.: 94,145,146

Xiao-min WANG Paper No.: 51

Xiu-ming WANG Paper No.: 77,110,111,124,126

Yin WANG Paper No.: 62,69

Yi-ze WANG Paper No.: 140

Yong-wei WANG Paper No.: 163

Yue-sheng WANG Paper No.: 25,76,83

Yun WANG Paper No.: 127

Zhen WANG Paper No.: 109,135

Zhi-bin WANG Paper No.: 92

Yan-chao WANG Paper No.: 92

Hai-e WEI Paper No.: 121,122

Jiang-bo WEI Paper No.: 11


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Xin-jiang WEI Paper No.: 98

Yong-kang WEI Paper No.: 57

Hao-dong WU Paper No.: 165

Li-na WU Paper No.: 121,122

Qian WU Paper No.: 53

Rong-xing WU Paper No.: 84,94

XXXX

Long XIA Paper No.: 68

Qing-guo XIA Paper No.: 73

Cai-wei XIAO Paper No.: 148

Cheng-feng XIAO Paper No.: 108

Ding-guo XIAO Paper No.: 112

Juan XIN Paper No.: 162

Jun XIN Paper No.: 104

Li-bo XIN Paper No.: 95

Zeng-ping XING Paper No.: 44,97,105

Kai-nan XIONG Paper No.: 113,152

Zhi-wen XIONG Paper No.: 182

Chun-dong XU Paper No.: 116

Chun-guang XU Paper No.: 112

Kai XU Paper No.: 44,97,105

Liang XU Paper No.: 18

Rong-qiao XU Paper No.: 127

Shi-qi XU Paper No.: 171

Tao XU Paper No.: 139

Tian-zhu XU Paper No.: 85,87

Xiang-wu XU Paper No.: 109,135

Xin-ran XU Paper No.: 37

YYYY

Cheng-feng YAN Paper No.: 162

Wei YAN Paper No.: 174

Xiang YAN Paper No.: 46

Xiao-jun YAN Paper No.: 58

Bao-he YANG Paper No.: 131

Dang-guo YANG Paper No.: 178,180,181

Jia-shi YANG Paper No.: 149

Jie YANG Paper No.: 80

Jing YANG Paper No.: 127

Lian-zhi YANG Paper No.: 164

Liu YANG Paper No.: 112

Ming YANG Paper No.: 18

Xiao-hui YANG Paper No.: 20,23

Lin-quan YAO Paper No.: 129

Yu YAO Paper No.: 20,54

Zhi-yuan YAO Paper No.: 28

Dong YE Paper No.: 117

Gui-ru YE Paper No.: 98

Yan-hui YE Paper No.: 182

Yu YIN Paper No.: 129

Zu-guang YING Paper No.: 22

Fa-peng YU Paper No.: 118

Guan-yin YU Paper No.: 62,70

Jing YU Paper No.: 84

Lan-zhen YU Paper No.: 84

Yong-gui YU Paper No.: 118

Li-li YUAN Paper No.: 49,117

Qin-wen YUE Paper No.: 119

ZZZZ

Yan ZHA Paper No.: 90

Ai-bing ZHANG Paper No.: 43

An-liang ZHANG Paper No.: 90

Chao ZHANG Paper No.: 52

Chen-rui ZHANG Paper No.: 163

Chuan-zeng ZHANG Paper No.: 76

De ZHANG Paper No.: 107

Hai-gang ZHANG Paper No.: 71

Han ZHANG Paper No.: 51

Hu ZHANG Paper No.: 133,134

Ji-long ZHANG Paper No.: 92

Kai ZHANG Paper No.: 172

Liang-liang ZHANG Paper No.: 164

Lin-lin ZHANG Paper No.: 151

Rui ZHANG Paper No.: 80,92

Rui-hua ZHANG Paper No.: 182

Sheng ZHANG Paper No.: 69

Shun-jun ZHANG Paper No.: 118

Tao-tao ZHANG Paper No.: 56

Yi ZHANG Paper No.: 180

Zhi-tian ZHANG Paper No.: 52

Chun-sheng ZHAO Paper No.: 24

Hui ZHAO Paper No.: 54


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Xian ZHAO Paper No.: 118

Xiang-yong ZHAO Paper No.: 116,119

Hai-rong ZHENG Paper No.: 53

Shi-jie ZHENG Paper No.: 89

Yan-qing ZHENG Paper No.: 104,113,152,162

Zhen-yu ZHENG Paper No.: 38

Hui ZHONG Paper No.: 78,80

Zheng ZHONG Paper No.: 120,125,128,138

Guang-ping ZHOU Paper No.: 81

Jin-juan ZHOU Paper No.: 29,32

Lin-sheng ZHOU Paper No.: 78

Long ZHOU Paper No.: 57

Sheng ZHOU Paper No.: 50

Sheng-qiang ZHOU Paper No.: 28

Xiao-ming ZHOU Paper No.: 21

Yu-jie ZHOU Paper No.: 26,27,31

Xiao-bo ZHU Paper No.: 30

Xin-en ZHU Paper No.: 159

Xing-bin ZHU Paper No.: 84

Yin-fa ZHU Paper No.: 182

Zhi-wen ZHU Paper No.: 14,91

Long ZOU Paper No.: 55