Effects of grain boundaries and dislocation density evolution on large strain deformation modes in fcc crystalline materials

Abstract

A dislocation-density based multiple-slip crystalline formulation and computational schemes have been developed and used for a detailed understanding and accurate prediction of interrelated physical mechanisms that occur on different length scales in fcc polycrystalline aggregates separated by grain boundary interfacial regions of random orientations and distributions. This constitutive framework accounts for the generation, trapping, interaction, and annihilation of mobile and immobile dislocation densities that are generally associated with finite-strain deformation and failure modes in fcc aggregates. Specialized interfacial regions have been introduced to account for dislocation-density and slip transmission, intersection, and blockage at GBs. It is shown that this blockage may result in the formation of pile-ups.