MODEL VALIDATION OF A 3D SIMULATION OF DISLOCATION DYNAMICS - DISCRETIZATION AND LINE TENSION EFFECTS

Some fundamental aspects of 3D computer modelling of plastic flow are presented together with the results of a detailed study of related approximations, such as the discretization of space and of dislocation line curvature. More specifically, the stress field generated by different discretizations of dislocation loops and the critical stress for dislocation multiplication through the Frank-Read mechanism, are compared to the predictions of the elastic theory of dislocations in the isotropic approximation. Although crude in appearance. the approximation adopted in these simulations to describe the curvature does not drastically affect the behaviour. Moreover. it leads to critical stress values for a pinned dislocation segment in excellent agreement with previous computations.