Electro-mechanically coupled pure-shear cyclic deformation of dielectric elastomers at different temperatures: Experiments and constitutive model

Abstract

This study initially conducts experimental observations on the electro-mechanically coupled pure-shear cyclic deformation of VHB™4910 dielectric elastomer at varying temperatures. The experimental results indicate that the temperature alteration has a considerable impact on the electro-mechanically coupled deformation of this elastomer. Under the strain-controlled cyclic deformation, the voltage application causes a decrease of stress response; but its decreased amount at different temperatures is almost the same. Under the stress-controlled cyclic deformation, the voltage application increases the ratchetting strain of the elastomer, leading to a reduction of sample thickness, which further amplifies the effect of voltage; meanwhile, the impact of voltage on the ratchetting amplifies as the temperature increases. Moreover, the electro-mechanically coupled cyclic deformation of VHB™4910 dielectric elastomer also shows significant loading level/loading rate dependence. Based on the experimental results, a temperature-dependent electro-mechanically coupled visco-hyperelastic constitutive model is presented. In the developed model, the strongly temperature-dependence of viscoelastic behavior and the role of voltage application of the elastomer are considered by incorporating the temperature-dependent shear modulus and dielectric constant. Finally, comparing the experimental results and simulated ones demonstrates that the developed model has a good capability for capturing the temperature-dependent electro-mechanically coupled cyclic deformation of dielectric elastomers.