The Effect of a Low Angle Grain Boundary on the Short Fatigue Crack Growth
The influence on the fatigue crack growth behaviour of a short edge crack due to different configurations of a nearby located low angle grain boundary is investigated under quasi-static and plane strain conditions. The geometry is modelled by dislocation dipole elements in a boundary element approach, and the plasticity is modelled by discrete dislocations. The crack is assumed to grow in a single shear mechanism due to nucleation, glide and annihilation of dislocations in the material. It was found that the sign of the dislocations in the grain boundary, the distances between them and the placement of the dislocations in the grain boundary with respect to preferred slip plane directions, all strongly influenced the growth behaviour.
P. Hansson and S. Melin, "The Effect of a Low Angle Grain Boundary on the Short Fatigue Crack Growth", Key Engineering Materials, Vol. 465, pp. 362-365, 2011