The effect of plastic deformation on crack initiation in fatigue

Qualitative considerations are given in the present paper concerning the effects of localized plastic deformation on the fatigue crack initiation life and stress intensity factor of a microcrack. The localized plastic zone is modelled as an elliptical inhomogeneity with eigenstrains. With the consideration of this localized plastic deformation, the calculated crack initiation cycle number is greater and the stress intensity factor of a micro-crack lower than those obtained without considering the plastic deformation effect.