Relationship between the parameters of the crack and strains at its tip in cyclic elastoplastic deformation

Abstract

1. A close relationship exists between the strain at the crack tip, crack length, and crack opening displacement in elastoplastic deformation. 2. The maximum fracture strain detected at a specific distance from the crack tip can be determined from the plastic strains accumulated prior to fracture in fatigue loading a smooth specimen. 3. The crack tip opening displacement can be determined using the equation of the crack contour. 4. Measurements of the crack opening displacement on the surface of the specimen make it possible to examine the growth of surface cracks whose depth cannot be measured.