Effects of texture gradients and strain paths on localization phenomena in polycrystals

Applications of crystal plasticity theory to the numerical modelling of large strain plasticity phenomena are considered. In particular, instabilities and localized deformation phenomena for FCC polycrystals subjected to various deformation modes are investigated. In-house finite element analyses based on a rate-dependent crystal plasticity model have been developed to simulate the large strain behaviour for sheet specimens subjected to plane strain, plane stress, and simple shear deformation modes. In the formulation, the plastic deformation of an individual crystal is assumed to be due to crystallographic slip. In the simulations, polycrystalline aggregates are modelled at various scales. This formulation accounts for initial textures, as well as texture evolution during large plastic deformations. The numerical analyses incorporate parallel computing features. The results of simulations for the above-mentioned deformation modes are discussed, and the formation of localized deformation in the form of shear bands is investigated.