Nonlinear coupled electro-mechanical behavior of a novel anisotropic fiber-reinforced dielectric elastomer

Dielectric elastomers are smart materials which produce mechanical actuation when subjected to an electrical field. In this study, we created an efficient framework to model the electromechanical coupling behavior of fiber-reinforced dielectric elastomers using large deformation continuum mechanics, electroelasticity and finite element method. We derived a consistent tangent modulus based on the Cauchy stress definition by incorporating dielectric effect into the tangent modulus. We used the Newton-Raphson method to solve the nonlinear finite element problem at hand with Abaqus and a new user defined material. In the next step, we calibrated the model with experimental tensile tests data on Cotton-reinforced Silicone rubber and check its validity by simulating the exact uniaxial tensile tests and comparing the results to experiments. We further checked the ability of the model to take the dielectric effect into account by comparing simulation results to available experimental data. We showed that the present model can trace the behavior of fiber-reinforced dielectric elastomers with proper accuracy. Also, we presented an example of a fiber-reinforced bending actuator and analyzed the effect of fiber orientation on its actuation and blocking force. We used the Maxwell-Garnett effective medium model to consider the effect of fiber inclusions on the dielectric constant of the material.