avshalom sheffer- seminar
TRANSCRIPT
Examination of stability for tensegrity structures through the theory of machines
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3/6 Stewart Platform-Spatial Triad6/6 Stewart PlatformSpatial Double TriadSpatial Tetrad . . , . . (1965) 3/6 Stewart Platform .
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Hunts Singular Configuration (1978)
- SP
Stewart Platform
3C4D5A5B4BMerlet (1989) 3/6-SP Grassmann line geometry -3C, 4B, 4D, 5A -5B.
Hunt et al. (2002) (2006) GrassmannCayley algebra 144 .
3/6 SP - .
-3D- . - .
Self-stress is createdSelf-stress is createdTwo linesintersect at a point
Self-stress is created -2D- .
3/6 SP- 3D Triad3D Double Triad3D Tetrad3D Pentad - .
() () - (-).
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-, (equimomental lines- eqml), (Shai and Pennock, 2005).Shai O. and Pennock G. R, "The Duality Between Planar Kinematics and Statics", ASME Design ngineering Technical Conferences, September, 24-28, 2005, in Long Beach, California, USA. Awarded the A.T. Yang Memorial Award in Theoretical Kinematics.
-, (equimomental screws - eqms), -ISA (Instantaneous screw axis) .
StaticsKinematics
. eqml . . .
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Dual KennedyKennedy
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Relative instant center of bodiesRelative instant center of bodies
Relative equimomental line of faces
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, .
( ). ,
, " ( ) ., eqml ( ) ., " ( ) ., eqml ( ) . :
, (Twist vector)., (Wrench vector).
- Assur Graphs (AG)
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-AG (Servatius et al, 2010). AG : .self-stress, , ., -AG .Servatius B., Shai O., and Whiteley W., 2010, Geometric Properties of Assur Graphs, European Journal of Combinatoric, 31(4), pp. 1105-1120
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Common Normal
Common Normal
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- (3/6 SP)
Common Normal
: -eqml (0,2), (0,4) ,(2,4), , ( ).
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Common Normal
: eqml eqms (0,4).
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6/6 SP18 : .
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6/6 SP
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- SP - SP
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5 - 6 5 - 6
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6/6 SP. -SP. (Slavutin M., Sheffer A., Shai O.): (AG) , (Cylindroid) , -ISA .
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- SP - SP .
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