A general theory was developed on the basis of Ohr’s model. Complicated cases which involved mixed-mode loading were considered. Explicit formulae were proposed for the critical condition of crack cleavage propagation after a number of dislocation emissions. In order to evaluate the effects of non-linear interaction between slip displacement and normal separation an analysis was made of fracture criteria, under combined dislocation emission and cleavage, that was based upon the Peierls framework. The calculation clearly showed that the non-linear theory gave slightly high values of the critical apparent energy release rate for a given load phase angle. The total number of emitted dislocations, at the onset of cleavage, which was predicted by the non-linear theory was higher than the number that was predicted by the linear theory.

Fracture Criteria for Combined Cleavage and Dislocation Emission. T.C.Wang: Philosophical Magazine A, 1996, 74[4], 983-1001