425 Study on Elasto-plastic Deformation and Buckling Phenomena of Thin Cylindrical Shell Subjected to Simultaneous Horizontal and Vertical Excitations

2006 ◽  
Vol 2006 (0) ◽  
pp. _425-1_-_425-6_
Author(s):  
Toshiyuki Tachibana ◽  
Tomohiro Ito ◽  
Katsuhisa Fujita
Keyword(s):  
Plastic Deformation ◽  
Cylindrical Shell ◽  
Thin Cylindrical Shell ◽  
Vertical Excitations

scholarly journals Multi-parameter actuation of a neutrally stable shell: a flexible gear-less motor

2017 ◽  
Vol 473 (2204) ◽  
pp. 20170364 ◽  
Author(s):  
W. Hamouche ◽  
C. Maurini ◽  
S. Vidoli ◽  
A. Vincenti
Keyword(s):  
Plastic Deformation ◽  
Cylindrical Shell ◽  
Principal Curvature ◽  
Experimental Testing ◽  
Fibre Composite ◽  
Piezoelectric Actuators ◽  
Piezoelectric Actuation ◽  
Thin Cylindrical Shell ◽  
Actual Structure ◽  
Morphing Structure

We have designed and tested experimentally a morphing structure consisting of a neutrally stable thin cylindrical shell driven by a multi-parameter piezoelectric actuation. The shell is obtained by plastically deforming an initially flat copper disc, so as to induce large isotropic and almost uniform inelastic curvatures. Following the plastic deformation, in a perfectly isotropic system, the shell is theoretically neutrally stable, having a continuous set of stable cylindrical shapes corresponding to the rotation of the axis of maximal curvature. Small imperfections render the actual structure bistable, giving preferred orientations. A three-parameter piezoelectric actuation, exerted through micro-fibre-composite actuators, allows us to add a small perturbation to the plastic inelastic curvature and to control the direction of maximal curvature. This actuation law is designed through a geometrical analogy based on a fully nonlinear inextensible uniform-curvature shell model. We report on the fabrication, identification and experimental testing of a prototype and demonstrate the effectiveness of the piezoelectric actuators in controlling its shape. The resulting motion is an apparent rotation of the shell, controlled by the voltages as in a ‘gear-less motor’, which is, in reality, a precession of the axis of principal curvature.

Sign in / Sign up

Export Citation Format

Share Document