A simplified method was introduced which was suitable for calculating crack interactions in multi-crack arrangements. It was based upon the concept of approximating the crack-generated stress field by that which was produced by a pair of edge dislocations of opposite signs which had Burgers vectors that were equal to the average relative displacement of the crack faces under the given load.

The Dislocation Approximation for Calculating Crack Interaction. R.Freij-Ayoub, A.V.Dyskin, A.N.Galybin: International Journal of Fracture, 1997, 86[4], L57-62