A Visco-hyperelastic Constitutive Model for Temperature-Dependent Cyclic Deformation of Dielectric Elastomer

Since dielectric elastomers (DEs) exhibit obvious nonlinear visco-hyperelasticity, and remarkable temperature dependence, it is difficult to accurately predict the cyclic deformation of DEs at various temperatures. To address this issue, an improved visco-hyperelastic constitutive model is proposed here to reproduce the complex temperature-dependent cyclic deformation of DEs. In the improved model, the Ogden model is chosen to provide the strain energy density representing the hyper-elastic response, a nonlinear viscosity evolution equation is used to depict the strong viscosity of DEs, and specific temperature-dependent parameters are incorporated to describe the cyclic deformation of DEs at various temperatures. Finally, the prediction capability of the proposed visco-hyperelastic model is validated by reproducing the cyclic deformation of VHB 4910 DE observed in experiments at different temperatures. This study provides a theoretical basis for the rational design of DE devices.