Interaction of wedge crack and grain boundary dislocations

Analysis of the interaction between a triple junction wedge crack and the pile-ups of grain boundary dislocations is used to investigate crack nucleation. Through the numerical solutions of a system of integral equations, the rearrangement of the dislocations and the stress redistribution due to the crack formation are fully taken into account in the analysis. Under remote tension, numerical results are obtained for the stress intensity factors, the dislocation populations on the grain boundaries, as well as the equilibrium crack lengths. The dependence of the crack length and the crack stability on the grain boundary orientations and the pile-up lengths is investigated. N$> 1998 Elsevier Science Ltd. All rights reserved.