Abstract
The stress intensity factor is a fracture mechanics parameter that describes the stress field around a crack tip. When the stress intensity factor is used as a fracture mechanics parameter, the small-scale yielding condition in which the plastic-zone size near the crack tip should be sufficiently small relative to the crack length must be satisfied. When a hardness distribution exists near a crack tip, the potential exists to deviate from the conditions. In this study, yield stress distributions as a hardness distribution which are given Gaussian distribution along the crack propagation path are considered in the crack propagation model based on the Dugdale model. The validity of the stress intensity factor around the yield stress distribution are investigated by conducting numerical analysis. As a result, when the magnitude of the yield stress change within distribution is large, small-scale yielding conditions tend to be unsatisfied.
