Nucleation of microcracks in localised slip bands: A dislocation model

Concerning decohesive fracture initiation in coarse localised slip bands, the model of Stroh-type blocked array of dislocations is advanced to account for the possibility of separation along a shear plane. Using a cohesive force approach, the cores of densely spaced dislocations in a coarse slip band of multiple coplanar pileups are taken into account as the nuclei of both possible traverse and longitudinal cleavages in a band. The equations of equilibrium of this dislocation population in stress field are built up towards establishing the fracture criteria as the limit conditions of the stability of the bandʹs equilibrium.