A numerical study of the influence of inclusion geometries in heterogeneous dielectric elastomers

Abstract

AbstractThe investigation and study of dielectric elastomers has emerged as an important research field in the last years with regard to the development of so called dielectric elastomer actuators (DEAs). The main advantage of this technology lies in the possibility of the design of soft actuators which are capable of large deformations. The main drawback is given by the high electric fields, which are necessary to drive such actuators. This drawback emerges from the reduced relative permittivity of dielectric elastomers, which leads to a low electromechanical coupling. In order to improve this handicap, a heterogeneous material structure, consisting of an elastomer matrix with barium titanate inclusions, is suggested. This contribution is concerned with the numerical analysis of the heterogeneous material including the electromechanical coupling for the dielectric elastomer. A mixed finite element formulation is employed to account for the nearly incompressibility of the dielectric elastomer. The numerical results show that the proposed material inclusions are capable to improve the stretch ratios of the elastomers. Different geometries of the inclusion are investigated with respect to the actuator deformation range.