3-DIMENSIONAL DEFORMATION PROCESS SIMULATION WITH EXPLICIT USE OF POLYCRYSTAL PLASTICITY MODELS

The combination of massive parallel processing and polycrystal plastic ity theory offers the potential for applying detailed microstructural models to macroscopic deformation processes. In this work the finite e lement method is used to solve for the three-dimensional deformation o f a plastic workpiece. The elemental constitutive response is derived from the microstructural response of a polycrystal aggregate situated in the element. Crystal orientations and their respective weighted con tributions to the aggregate response are selected to approximate the o rientation distribution derived from experimental pole figure measurem ents. The interaction of the material symmetry adopted in analysis of pole figures and the boundary conditions posed in the plasticity bound ary value problem are examined, Through the introduction of distinct a ggregates with decreasing crystal to aggregate ratio, an inhomogeneous material response is developed where: (1) the orientation distributio n becomes well approximated only by a collection of spatially distinct aggregates, and (2) these aggregates experience deformation paths of increasing variation. It is shown that the use of spatially distinct a ggregates in a material experiencing local kinematic inhomogeneities t hroughout its deformation history leads to texture predictions that co mpare favorably with experimental measurements.