ABSTRACT
This study reconstructs isotropic Cam-clay model based on multiplicative decomposition of the deformation gradient. The aim of the reconstruction is a formulation considering the existence of the state boundary surface in Cauchy stress – specific volume space, which is a basic experimental fact of Cam-clay model. For this purpose, we define a hyperelastic strain energy function per unit volume in the intermediate configuration and formulate using zeta stress and Eshelby-zeta stress derived by considering the non-negativeness of plastic dissipation. This study also constructs an implicit stress update algorithm for the model and derives the tangent modulus consistent with the algorithm to incorporate the proposed model into a finite element analysis code. Moreover, this study demonstrates the significance of the proposed model by comparing an existing model using Kirchhoff stress, and verifies the stress update algorithm.
