11Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
장지은 , 한국과학기술원 건설 및 환경공학과 석사과정정형조 , 세종대학교 토목환경공학과 조교수정 운 , 현대건설기술개발원 주임연구원이인원 , 한국과학기술원 건설 및 환경공학과 교수
MR 유체 감쇠기를 이용한 사장 케이블 제진 시스템의 실험적 검증
22Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Objectives
• To experimentally verify the performance of the MR
damper-based control systems for suppressing vibration of
real-scaled stay cables using various semiactive control
algorithms
33Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Cable Damping Experimental Setup
Schematic of smart cable damping experiment
shaker flat-sagcable
spectrumanalyzer
MR dampers
digital controller
)(tFd
)(tFs
dw
u
ew
44Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Cable
Real-scaled cable at HICT
parameters valuesL 44.7 m
m 89.86 N/m
T 500 KN
1.34 m13.4 m
8.372.53 Hz
dx
0005.00015.0
2
1
i
0
sx
55Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
dx sx
),( txvx
where ),( txv)(tFd dxx
: transverse deflection of the cable
: transverse damper force at location
)(tFd )(tFs
)(tFs sxx
L
: transverse shaker force at location : angle of inclination
Cable model
66Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
MR damper
• MR controllable friction damper (RD-1097-01 from Lord Corporation)• Maximum force level: 100 N• Maximum voltage: 1.4 V• Location : 1.34m from bottom support
77Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Cable exciting system (Kim et al. 2002)
temtF sin)( force exciting Harmonic 2
mass exciting : frequency exciting : where
m
(1)
88Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Controller
• The controller is constructed by the Matlab Real-Time Workshop executed in real time using MS Visual C++.• The measured responses are acquired from displacement and acceleration sensors at damper location and converted into digital data by NI DAQ Card-6062E.
99Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Control algorithms: to calculate the command voltage input
• Passive-mode cases
• Semiactive control cases (Jansen and Dyke 2000)
- Clipped-optimal control algorithm - Control based on Lyapunov stability theory - Maximum energy dissipation algorithm - Modulated homogeneous friction algorithm
1010Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Experimental Results Displacement in free vibration
Time (sec)
Dis
plac
emen
t (m
)
1111Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Damping ratios in the passive-mode cases by Hilbert transform-based identification method
Dam
ping
rat
io
(%)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0 5 10 15 20 25
passive V=1.4 passive V=1.3 passive V=1.2passive V=1.1passive V=1.0passive V=0.6passive V=0.0uncontrolled
Amplitude (mm) at the location of 10.2 m away from the bottom support
1212Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Damping ratios in the semiactive control cases by Hilbert transform-based identification method
Amplitude (mm) at the location of 10.2 m away from the bottom support
Dam
ping
rat
io
(%)
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
3 5 7 9 11 13 15 17
Passive offPassive onClipped optimalLyapunovMHFMEDA
1313Structural Dynamics & Vibration Control Lab., KAIST, KoreaStructural Dynamics & Vibration Control Lab., KAIST, Korea
Conclusions
Semiactive control systems significantly improve the mitigation of stay cable vibration over the uncontrolled and the passive-off cases.
The Modulated homogeneous friction algorithm shows nearly the same performance as the passive-on case.
The performance of MR damper-based control systems for suppressing vibration of stay cables is experimentally verified.
The control based on Lyapunov stability and the clipped- optimal control show slightly better performance than the passive-on case.