The influence from different grain boundary configurations on the crack growth rate of a microstructurally short edge crack, located within one grain and subjected to remote fatigue loading, was studied. The study was performed using a dislocation formulation, were the geometry was described by dislocation dipole elements in a boundary element approach and the plasticity by discrete dislocations, located along specific slip planes in the material. Plane strain and quasi-static conditions were assumed. The crack was assumed to grow in a single shear mechanism due to nucleation, glide and annihilation of discrete dislocations. Different grain boundary configurations in front of the growing crack were considered, including both high angle and low angle grain boundaries. It was shown that both grain boundary configuration and distance between the crack and a grain boundary had a pronounced influence on the crack growth rate.

Grain Boundary Influence on Short Fatigue Crack Growth Rate. P.Hansson, S.Melin: International Journal of Fracture, 2010, 165[2], 199-210