The stress field for a screw dislocation near cavities and straight boundaries

The stress distribution and dislocation forces for screw dislocations near cavities and straight boundaries are examined, depending on the selected cut used to impose a displacement discontinuity and create a dislocation. The location of the equilibrium dislocation position is determined in each considered case. The slip-induced stress amplification in thin ligaments between a cavity and a straight boundary, between the inner and outer surface of an eccentric hollow cylinder, and between two approaching cavities in an infinite medium are calculated. It is shown that in the limit of vanishingly small ligament width d, the shearing stress amplifies at the order of d−1/2.