A fatigue crack nucleation model for anisotropic materials

Abstract

Based on Tanaka-Mura's dislocation-dipole pile-up configuration, a formulation of mixed mode fatigue crack nucleation is derived using the Stroh formalism for generally anisotropic materials. The fatigue life is explicitly expressed as inversely proportional to the stored plastic energy, depending on the material's anisotropic elastic matrix F−1, surface energy, Burgers vector, and lattice resistance. The model has been shown to agree with experimental observation on critical slip planes in PWA 1493 single crystal Ni-base superalloy.