Slip Continuity in Explicit Crystal Plasticity Simulations Using Nonlocal Continuum and Semi-discrete Approaches.

摘要

Slip continuity across element boundaries in explicit finite element simulations is enforced through nonlocal penalty constraints applied to continuum crystal plasticity relations and in a nonlocal, semi-discrete crystal slip model. The continuity constraints provide additional coupling within the plastic deformation field, and a length scale effect is introduced. The deformation field becomes more diffuse with reduced physical size of the model region and the strength increases. The semi-discrete method produces dislocation pile-ups and slip gradients along discrete slip planes, but the simulation approach is ultimately unsatisfactory. Consideration of the physical spacing of dislocations and the typical size of dislocation cells in deformed metals elicits concerns about the applicability of continuum slip models with sub-micron spatial resolution.