In order to simulate dislocation distributions around a mode-I crack, edge dislocations were allowed to be emitted from a crack tip along many possible slip-planes which contained the crack tip. It was found that the final distribution depended upon the order of emission. Many dislocations were emitted at the same time when the slip force exceeded the lattice friction for dislocation motion. It was noted that the dislocations were more uniformly distributed than in the case of sequential emission. The shielding effect for a given number of emitted dislocations was less when the dislocations were distributed along more slip planes. The shape of the plastic zone was different to, but the size was comparable with, a plastic zone that was based upon the Von Mises or Tresca criterion. A distinct dislocation-free zone appeared when there was a critical stress intensity factor for dislocation emission.

Edge Dislocations Emitted along Multiple Inclined Slip Planes from a Mode-I Crack – II. Simultaneous Emission. C.F.Qian, J.C.M.Li: Mechanics of Materials, 1996, 24[1], 11-7