Prediction model for initiation in cracked component under very low cycle fatigue

Abstract

In this paper, a model is proposed to predict the initiation cycle of a cracked component under very low cycle fatigue. The prediction model is based on the simple assumption that mechanism of crack initiation in a cracked component under very low cycle fatigue loading is the same as that under monotonic loading, and is given in terms of the plastic component of monotonic J and cyclic Delta J. For validation, predicted cycles are compared with displacement-controlled cyclic C(T) test data with two load ratios and load-controlled C(T) test data with two amplitudes. The predicted cycles based on 0.2 mm crack growth are similar in all cases.