AN APPROXIMATED FORMULATION OF OGDEN MODEL FOR RUBBER-LIKE SOLIDS

Abstract

This paper presents a new approximated formulation of Ogden model for isochoric deformation of rubber-like solids. In the formulation, the principle stretches in the strain energy function of Ogden model are approximated by Taylor series, and they are expressed by the invariants of material logarithmic strain. Then, the stress-strain relation and the elastic tangent moduli of the approximated model are developed together with their numerical implementations. Finally, accuracy of the model is evaluated in comparison with the exact Ogden model, and the necessary condition for proper approximation is shown on the basis of these results.