INTERACTION OF AN EDGE DISLOCATION WITH A WEDGE CRACK

The elastic interaction of an edge dislocation with a wedge crack is i nvestigated using Muskhelishvili's complex potential treatment of elas ticity. The stress intensity factors induced by the dislocation, the s train energy, and the image force acting on the dislocation are formul ated, calculated, and plotted. Especially, the influence of wedge angl e on the shielding effects and on image forces is investigated. The re sults show that the radial component of the image force is inversely p roportional to the distance from the crack tip to the dislocation and the tangential image force increases with increasing wedge angle as th e dislocation position is kept unchanged. When the slip plane passes t he crack tip, whether the edge dislocation shields or antishields the crack tip depends on its Burgers vector. In this case, the slip plane of the edge dislocation of Burgers vector b(1) + ib(2) = be(i theta ma x) inclined at an angle theta(max) with respect to the positive real a xis corresponding to the maximum mode I crack shielding increases slig htly to a maximum and then decreases with increasing wedge angle. Rega rdless of wedge angle, the maximum mode II shielding (or anti-shieldin g) occurs when the dislocation is located at the positive real axis. ( C) 1995 American Institute of Physics.