Woodruff School of Mechanical Engineering
Mechanical Engineering Seminar
Modelling homogeneous and composite soft dielectric elastomers: performance, instabilities, electrostrictive effects.
Prof. Massimiliano Gei
Department of Mechanical and Structural Engineering, University of Trento
Friday, October 12, 2012 at 1:30:00 PM
MRDC Building, Room 2404
Dr. Jun Ueda
Abstract: Predictive models for Dielectric Elastomer Actuators require the nonlinear solid mechanics theory of soft dielectrics. This is certainly true for homogeneous systems, but also for devices made of composite materials, where the insertion of stiff conductive particles in the soft matrix may help to improve the overall actuation performance. In the talk, I present a theoretical framework to investigate a wide range of instabilities in both homogeneous and composite-manufactured actuators: pull-in/electromechanical instability, buckling-like modes and band-localization failure, that can be analyzed taking into account all the geometric and electromechanical properties of the device such as i) nonlinearities associated with large strains and the employed material model; ii) initial prestretch applied to the system; iii) dependency of the permittivity on the deformation (electrostriction). In the second part I will focus on the performance of layered composites highlighting the effect of the induced dielectric anisotropy.
Biography: Massimiliano Gei is Associate Professor of Solid and Structural Mechanics at the University of Trento, Trento, Italy. Born in 1971, he graduated in 1997 in Civil Engineering at the University of Bologna, Bologna, Italy, and received the Ph.D. in Materials and Structural Engineering from the University of Trento in 2001. His research interests include electro-active polymer technology, smart-structure design, metamaterials, band-gap structures, and finite elasticity. Regarding dielectric elastomer actuators, he is an expert of instability phenomena and modelling of composite materials and is affiliated to the European Scientific Network for Artificial Muscles (ESNAM).