Takaya KAMIKUBO

Non-linear Finite Deformation Analysis Including Pressure-dependent Boundary Conditions

Kunio TORII

This paper is concerned with finite deformation problems that include pressure-dependent boundary conditions. In this case, a direction of pressure varies with the deformations of the surface on which the pressure is applied. In finite deformation analysis of such problems, we should consider the deformation-dependence of boundary conditions.
For typical example of such finite deformation problems, we conduct simulation of triaxial compression and extension tests. The purpose is to investigate the influence of non-uniform or localized deformation from both of macroscopic and microscopic points of view. First, we computed the pure mechanical responses of constitutive model in the stress conditions of triaxial compression and extension to estimate the results of ideal experiments under uniform deformation. Secondary, we conducted a nonlinear finite element analyses for triaxial compression and extension to obtain macroscopic responses of the specimens.
From these results, macroscopic critical stress ratio in extension is about 10 percent smaller than that in compression. This implies that the macroscopic yield surface of specimens is different from the one represented by constitute model.