LAUSR

Abstract Crystal plasticity finite element analyses are carried out in three dimensions to investigate void evolution in hexagonal close packed single crystals. Two crystallographic orientations are considered favoring either slip or twinning, which are both accounted for in the formulation. The effect of stress state is analyzed by varying some nominal measure of overall triaxiality. The orientation and stress state dependence of the effective response, including void evolution, are characterized in some detail, as driven by the micromechanics of plastic deformation. Particular emphasis is laid on crystallographic aspects, such as the emergence of deformation sectors, the influence of the polar character of twinning, and directional void growth. In addition, all analyses were conducted up to strain localization so as to uncover orientation and crystallographic aspects of void coalescence. The potential implications of slip and twinning mechanisms on ultimate failure in hexagonal close packed materials are discussed.