A two-scale deformation model for polycrystalline solids using a strongly-coupled finite element methodology

A two-scale, finite element framework for analysis of polycrystalline solids at the continuum and crystal scales is demonstrated. The framework is strongly coupled in the sense that the response at the continuum scale directly bears on the response at the crystal scale and vice versa. Data needed at one scale from computations at the other scale are generated on-the-fly. Two important issues are addressed: the projection of continuum scale motion onto crystal scale aggregates and the averaging crystal scale stresses for use at the continuum scale. The framework is implemented in a scalable parallel computing environment and applied to two examples with different geometries and loading modes. It is shown that combining formulations for the crystal and continuum scales can provide more detailed and accurate results in comparison to a single-scale finite element approach that invokes a simpler scale-linking methodology.