The propagation of an adhesive crack through an anisotropic heterogeneous interface is considered. Tuning the local toughness distribution function and spatial correlation is numerically shown to induce a transition between weak to strong pinning con
ditions. While the macroscopic effective toughness is given by the mean local toughness in case of weak pinning, a systematic toughness enhancement is observed for strong pinning (the critical point of the depinning transition). A self-consistent approximation is shown to account very accurately for this evolution, without any free parameter.
Molecular static simulations have been performed to study the interaction between a single dislocation and a substitutional Al solute atom in a pure crystal of Ni. When the Al solute is situated at intermediate distance from the slip plane, we find t
hat both edge and screw dislocations experiment a non-negligible binding energy. We show that for such length scale the description of the elasticity theory can be improved by taking into account the spreading of dislocation cores via the Peierls-Nabarro model.
