ICAMS / Interdisciplinary Centre for Advanced Materials Simulation


Crystal plasticity modeling with boundary consideration

Date: 13.07.2009
Place: ICAMS, Ruhr-Universität Bochum, Germany

Anxin Ma

In regions near the grain boundary (GB) strain gradients are easily formed, which can cause lattice rotations. Such lattice rotations are described by densities of geometrically necessary dislocations (GND) as internal variables to keep the lattice continuity. The constitutive relations for the material far from grain boundaries are already well established. In contrast, if there exists GB in the neighborhood of one material point, lattice continuity will lose its meaning along the GB normal direction and the concept of GNDs obviously cannot be used as internal variable to re ect the nonlocal e ect such as dislocation-GB interaction and GB slide. For polycrystals with rather large grain size this dislocation-GB interaction can smear out for a small volume fraction while for ultra ne grained polycrystals this interaction mechanism plays a dominant role. This presentation will focus on this topic and discuss some modeling and simulation results. For more

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