Modelling the curing process in particle-filled electro-active polymers with a dispersion anisotropy

Even for a moderate actuation, a large electric voltage requirement hinders the application of electro-active polymers (EAPs) in many areas. Hence, among other mechanisms, the actuation enhancement in EAPs is performed via inclusions of high-dielectric-permittivity fillers in the matrix material in the uncured stage. Moreover, to obtain an optimum advantage from the high-dielectric-permittivity fillers, an electric field can be applied during the curing process which helps the particles to align in a preferred direction. To be specific, recent experimental evidences show that these particles form a dispersed anisotropy rather than a perfect transverse anisotropic structure. The polymer curing process is a complex (visco-) elastic phenomenon where a liquid polymer gradually transforms into a solid macromolecular structure due to cross-linking of the initial solution of short polymer chains. This phase transition comes along with an increase in the material stiffness and a volume shrinkage. In this paper we present a phenomenologically inspired large strain framework for simulating the curing process of particle-filled electro-active polymers with a dispersion-type anisotropy that can work under the influence of an electro-mechanically coupled load. The application of the proposed approach is demonstrated with some numerical examples. These examples illustrate that the model can predict common features in particle-filled dispersed electro-active polymers undergoing curing processes in the presence of an electro-mechanically coupled load.