The fatigue crack closure after overload was measured by small foil strain gages. The effect of overload on crack closure stress and crack propagation rate was observed to extend over a range several times larger than the overload plastic zone. Analysis of experimental data showed that the extra amount of plastic deformation introduced by the overload was the controlling factor. A relationshp between crack closure stress and crack length in the affected zone was found, and the amount of plastic deformation by the overload was estimated. This estimate was further confirmed by analysis of the crack closure pictures. © 1983.
Gan, D., & Weertman, J. (1983). Fatigue crack closure after overload. Engineering Fracture Mechanics, 18(1), 155–160. https://doi.org/10.1016/0013-7944(83)90104-2