DAMAGE ACCUMULATION DURING INITIATION AND SHORT CRACK GROWTH REGIMES

Abstract

Abstract— The birth and growth of short cracks is analysed from an elastic‐plastic fracture mechanics viewpoint. Low to high cumulative damage tests from the low stress to high strain regime indicate that there is no crack initiation period in the metallurgical sense and that cracks grow from the first cycle, but at a slow rate. The initiation phase terminates when one crack starts to dominate and accelerates to failure, its initial size being given by image for the medium carbon steel tested here, of grain size 56 μm.