Rate-dependent electromechanical behavior of anisotropic fiber-reinforced dielectric elastomer based on a nonlinear continuum approach: modeling and implementation

Dielectric elastomer (DE) characteristics and potentials have led to more efficient actuators in soft robots. Meanwhile, more possibilities could be explored by incorporating other properties, including viscoelasticity and anisotropy. The present study focuses on establishing constitutive laws to capture the electromechanical coupled behavior of anisotropic viscoelastic fiber-reinforced DEs. The proposed model is presented in the framework of the strain energy function, nonlinear electro-elasticity, and nonlinear continuum mechanics approach. The derived model has been calibrated and validated using available experimental results. An Abaqus subroutine has also been developed and used for finite element simulation. Rate-dependent governing equations of a fiber-reinforced layered DE have also been considered as well as the effects of fibers direction and actuating electric field. Obtained results indicate the efficiency of the suggested model and developed subroutine in describing rate-dependency, electro-elasticity, and anisotropy. According to the findings, stiffening the bending actuator with fibers can drastically affect the deflection and force of the sample under different loading conditions.