Modeling The Anisotropic Behavior Of Polycrystals With Voids

Abstract

The viscoplastic selfconsistent (VPSC) formulation is by now a well established
approach for simulating texture development and constitutive response during plastic forming
of high and low-symmetry aggregates. In this work we consider the presence of voids of
anisotropic shape inside 3D polycrystals submitted to large strain deformation. For this
purpose, the originally incompressible VPSC formulation has been extended to deal with
compressible polycrystals. In doing this, both the deviatoric and the spherical components of
strain-rate and stress are accounted for. As a consequence, the extended model provides now
a relationship between the void growth rate and the hydrostatic pressure, which in turn can be
used to keep track of the porosity evolution in the polycrystal. The model is applicable to the
stage of void growth but does not account for void nucleation or coalescence. The extended
VPSC model is used here to study the role of voids (and their evolution) in texture evolution.
In addition, we also study the coupling between texture, void shape, crystal symmetry and
strain rate on both, mechanical response and void growth.