Extension of classical viscoelastic models in large deformation to anisotropy and stress softening

• Hyper-visco-elastic model for elastomers and soft tissues.
• Sphere unit approach on classical IVM and CIM model.
• Description of uniaxial, planar and biaxial tests.
• Extension of the models to initial anisotropy.
• Coupling hyper-visco-elastic and stress softening models.

In this paper, an extension of two classical viscoelastic models adapted in large deformation for incompressible rubber like materials or soft tissues is proposed. These models are built by using a three dimensional homogenization by means of a sphere unit approach. Thus several comparisons between classical formulations and homogenization on a sphere unit formulation are proposed. An adaptation of those models to describe anisotropy is proposed. Finally an extension of those models to take into account stress softening is described.