On the prediction of yield surfaces by the crystal plasticity models for fcc polycrystals

Numerical averaging procedures utilizing the finite element technique have been proposed in the literature as an improvement over the Taylor averaging scheme for modelling the constitutive behavior of polycrystal aggregates w ith a known distribution of lattice orientations and a known single crystal constitutive behavior. In this paper, yield surfaces are predicted for fee polycrystals with different textures (including random textures and rollin g textures) by both the finite element technique and the fully constrained Taylor model. Using both techniques, we study the influence of texture, pol ycrystal averaging method, and the evolution of slip anisotropy (due to var ious latent-hardening assumptions) on stress-space contours at constant off set strain. Results show that slip anisotropy and latent hardening assumpti ons may be more significant than preferred crystallographic orientations (t exture) in determining the anisotropic stress response. (C) 2000 Elsevier S cience S.A. All rights reserved.