The Facet-Gurson model for ductile damage process

Abstract

An attempt is made to incorporate the effect of texture-induced plastic anisotropy in Gursontype porous plasticity theory. The plastic anisotropy is modelled by using the recently developed Facet method in stress space. The Facet method relies on the theory of dualplastic potentials and proposes an expression for a yield surface. The parameters of such yield surfaces are determined by fitting to the results of virtual mechanical tests. These virtual tests can be performed using any of the existing micromechanical models, such as Taylor theory, provided that the crystallographic texture of the material is known. The coupling of anisotropy and damage is implemented by replacing the effective stress of the Gurson matrix by the anisotropic effective stress calculated by the Facet method, as well as by adjusting one anisotropy-related parameter in the flow potential. The coupled model is applied on mono-And poly-crystalline materials that have an initially spherical void, with 1% void volume fraction. The capability of the coupled model is assessed with the results obtained from crystal plasticity based FE cell calculations.status: publishe