The effects of overload on the fatigue crack growth in ductile materials predicted by plasticity-corrected stress intensity factor

On the basis of plastic zone toughening theory, a plasticity-corrected stress intensity factor (PC-SIF) is proposed to describe the effects of overload on the fatigue crack growth in ductile materials. By use of this new crack driving force parameter a theoretical correlation of the Paris law with crack tip plastic zone is established. Comparison with extensive experimental data showed that the PC-SIF describes fairly well the effects of the crack length and different loading variables, including the applied stress intensity factor range, load ratio, overload extent and overload number, on the overload retardation.