A NEW APPROACH TO THE DETERMINATION OF FATIGUE-CRACK INITIATION SIZE

In this paper, the definition of fatigue crack initiation size and det ermining method were presented on the basis of the Iron-propagating cr acks behaviour. The physical significance of fatigue crack initiation size was explained from the point of view of the fatigue damage. Fatig ue crack initiation size is obtained by predicting a non-propagating c rack at the notch root under fatigue limit loading. On the basis of th e fatigue crack initiation size determined in this paper, the fatigue crack initiation life was predicted by means of the local stress-strai n approach, under both constant amplitude and random loading, and good agreement is demonstrated with experimental data. (C) 1998 Elsevier S cience Ltd. All rights reserved.