The behavior of an extended dislocation near to an elliptical blunt crack was investigated. The equilibrium separation between Shockley partials and the critical value of stacking fault energy for the formation of extended dislocations by dissociation reaction as well as the extended dislocation emission criterion were developed. The results showed that the equilibrium separation increased as the extended dislocation tended to the blunt crack. If the stacking fault energy was comparable to the critical energy for dissociation in a perfect medium, complete dislocations could dissociate to form extended dislocations near the blunt crack. The critical stress intensity factor for extended dislocation emission increases with the stacking fault energy and the curvature radius of the blunt crack tip. Moreover, the critical stress intensity factor for extended dislocation emission was far lower than the critical stress intensity factor for edge dislocation emission.

Behavior of an Extended Dislocation near an Elliptical Blunt Crack. H.P.Song, Q.H.Fang, Y.W.Liu: Chinese Physics Letters, 2009, 26[9], 096102