POTENTIAL INFLUENCE OF MICROSTRUCTURAL MORPHOLOGY ON THE VISCOPLASTIC FLOW OF TWO-PHASE POLYCRYSTALS

摘要

Most recent homogenisation theories for nonlinear behaviour combine a linearisation procedure with an appropriate linear scale transition scheme. While the definition of improved linearisation formulations is currently the subject of active research, the used linear models are often standard ones, namely the classical self-consistent (SC) scheme when polycrystals are considered. We investigate here the potential influence of the phase distribution in the case of a two-phase polycrystal with hard and soft grains. Various linear models are combined with Suquet-Ponte Castaneda's variational formulation for anisotropic media, including two-scale transition models, and are compared with SC predictions. Phase distribution effects are significant only when the contrast of critical resolved shear stresses is above about 3.