Plasticity-Induced Fatigue Crack Closure in High-Strength Steels: Is it a Real Phenomenon?

Abstract

High-resolution elastoplastic simulations of a plane-strain tensile crack under cyclic loading visualised the Laird-Smith mechanism of fatigue crack growth, which manifested the effects of K and overload, but no signs of crack closure. Simulations discarded the supposed mechanism of plasticity-induced crack closure (PICC) via out-of-plane stretching of material elements filling-in the crack and coming in contact at unloading. Specimen compliance curves turned out to be nonlinear merely by virtue of plasticity with no contribution of crack closure. Thus the results manifested the ambiguity of main justifications about the phenomenon of PICC.