ABSTRACT
A novel constitutive formulation is developed for finitely deforming hyperelastic materials that exhibit isotropic behavior with respect to a reference configuration. This chapter presents the mathematical formulation of a finite element model based on the stress-strain constitutive equations derived for isotropic hyperelastic materials using logarithmic strain. The strain energy function based on the log-strain approach was applied for the development of finite element procedure for the solution of large deformation problems for rubber materials. The hyperelastic models are higher-order forms of linear elastic models in which the stresses are some functions of the total strains or stretches. This relationship is derived from an elastic potential and rubber materials inevitably involve large strains. This strain energy function has proved that leads to reasonably well fitting of the experimental data with the theoretical predicted stress/strain constitutive equation.
