Elastic strain energy analysis of the dislocation structures in fatigue

Abstract

The dislocation structures which evolve during fatigue have been investigated in terms of the elastic strain energy. Mathematical models for the configuration of dislocation dipoles such as the ladder structure and vein structure are introduced. The elastic strain energy for these models is calculated and evaluated using the eigenstrain method. This analysis may provide insight as to why persistent slip bands in fatigued copper are created after the vein structure reaches a certain stage and why persistent slip bands consist of ladder rungs with an equal spacing of about 1.3 μm at room temperature.