A method was presented that combined the modelling of cracks by distributed dislocation dipoles with developing plasticity represented by discrete dislocations moving along slip bands. Crack growth was due to the emission of dislocations from the crack tip along preferred slip planes. Eventual annihilation of dislocations occurred by reunion with the corresponding displacement steps of the crack surface. Crack surface overlap was not permitted. The equilibrium state for each load increment was solved iteratively, permitting various crack geometries. The method was applied to the problem of a short edge crack, growing in mode-I, due to fatigue loading. It was shown that the development of a local plastic zone and the propagation of the crack could be monitored in detail.

A Tool to Model Short Crack Fatigue Growth using a Discrete Dislocation Formulation. C.Bjerkén, S.Melin: International Journal of Fatigue, 2003, 25[6], 559-66