The formation of a plastic zone in the presence of a crack, in a bicrystal, was modelled by two-dimensional discrete dislocation dynamics. The influence of a large number of parameters was studied: the misorientation, the emission from the crack tip and the obstacle density which modifies the internal stress (hardening) and degree of localization of mobile dislocations (slip bands). Emphasis was put on obtaining the best ductility, since the focus was on face centered cubic materials. Finally, a strong effect of the plastic model on the dynamics and on the secondary slip (intensity and localization), beyond the influence of the initial distribution of sources and obstacles, was reported.

Plasticity Localization ahead of a Crack Tip Modeled by 2D Discrete Dislocation Dynamics. D.Tanguy, D.Delafosse, M.Razafindrazaka: Philosophical Magazine, 2010, 90[11], 1415-34