Modeling of electro-viscoelastic dielectric elastomer: a continuum mechanics approach (Q1982364)

The authors derive a micro-mechanics-based rheological model for an incompressible isotropic electro-viscoelastic material. Such electroactive polymers may develop large strains under electrical loads. The proposed model needs only three material parameters: shear modulus, minimal extensibility and viscosity coefficient to fit the available experimental data. This is half the number of material parameters introduced in earlier work. In deriving the constitutive theory, the authors use a multiplicative deformation gradient decomposition into elastic and viscous parts. The derived constitutive relations are thermodynamically admissible. In developing their theory, the authors assume that the electric field equilibrates faster than the deformation, thus implying that the electric field does not affect the dissipation. The proposed model is validated using results from uniaxial experimental data, and good agreement is reached. Some conclusions are discussed concerning the ability of the model to describe the rheological behavior of dielectric elastomers.