Applicable limit of the stress intensity factor for steep yield strength distribution

The small-scale yielding condition is a requirement for applying the stress intensity factor as a fracture mechanics parameter. The existing evaluation method for small-scale yielding assumes constant yield strength around the crack tip. Therefore, when a steep yield strength distribution exists along the crack propagation path, it is inadequate for evaluating the condition. The effect of the yield strength distribution on the scale of yielding was analytically clarified, especially when small-scale yielding deviated for a steep distribution. A new small-scale yielding criterion, which can be applied when subject to yield strength distribution, was proposed and demonstrated.