Discrete dislocation dynamics were used to build a model for fatigue-crack initiation in a surface grain. The dislocations were modelled as line-singularities in an elastic medium, where they could be generated from pre-existing sources, glide or annihilate. The simulation revealed features that might give rise to fracture initiation. Three different potential areas of fracture (surface, grain interior, grain boundary) were found which corresponded to those found in experiments. A comparison with experimental results on crack nucleation was impeded by computational expense; which limited the number of cycles that could be simulated.

A Discrete Dislocation Dynamics Study Aiming at Understanding Fatigue Crack Initiation. S.Brinckmann, E.Van der Giessen: Materials Science and Engineering A, 2004, 387-389, 461-4