Dislocation emission and cleavage process at crack tip

The competition process between dislocation emission along a pair of symmetric slip planes and quasi-cleavage at Mode I crack tip is investigated in this paper. The equilibrium positions and the total number of emitted dislocations are determined based on Peierls framework, The fundamental physical events at the crack tip are reviewed. The crack blunting effects on the stress fields near the top of the blunted crack are analysed.