Fiber-constrained dielectric elastomer composites: Finite deformation response and instabilities under non-aligned loadings

INTERNATIONAL JOURNAL OF SOLIDS AND STRUCTURES

卷:184

Article; Proceedings Paper

Siboni, Morteza H.¹  Castaneda, Pedro Ponte¹ 

[1] Univ Penn, Dept Mech Engn & Appl Mech, Philadelphia, PA 19104 USA

关键词: Electrostriction;    Smart materials;    Electric torques;   

DOI  :  10.1016/j.ijsolstr.2019.03.027

来源: Elsevier

【 摘 要 】

This paper is concerned with the development of finite-strain constitutive models for electro-active composites consisting of initially aligned, rigid dielectric fibers of elliptical cross-section that are distributed randomly in a dielectric elastomer matrix. For this purpose, we make use of a variational approach that partially decouples the mechanical and electrostatic contributions to the overall energy and leads to a minimum principle for the average orientation of the fibers. The resulting macroscopic electroelastic constitutive model accounts for electric and mechanical torques on the fibers, as well as for the microstructure and its evolution under finite deformations. In particular, the model characterizes the rotation of the fibers for general externally applied electromechanical loadings, predicting bifurcation instabilities for the special case of aligned loadings. To elucidate the main features of the model, we consider the application to a dielectric elastomer composite actuator and investigate the effects of fiber aspect ratio and initial fiber orientation on its macroscopic response. In addition, the new results are compared with the predictions of an earlier model approximating the fiber rotations by purely mechanical effects. (C) 2019 Elsevier Ltd. All rights reserved.

【 授权许可】

Free