ABSTRACT
Often, large plastic deformation in polycrystals is influenced by the slip and its
gradients, which arise at the length scales of microstructural heterogeneities, and in
particular grain boundaries. In this work a non-local multiple-slip crystal plasticity
formulation, i.e. augmented with gradients, is presented and applied to
polycrystalline aluminum aggregates. Physically based dislocation-density
mechanisms representative of different slip interactions coupled to plastic curvature
have been formulated within the gradient-crystal plasticity framework. Specialized
finite element methodologies that account for higher-order deformation are also
presented and used to investigate how certain dislocation-density activities at grain
boundaries are directly related to shear strain localization for polycrystalline
aggregates which lead to damage tolerant armor alloys.