INFLUENCE OF CONTACT LOADING ON FRETTING FATIGUE BEHAVIOR

Fretting induced cracking is commonly observed in industrial component s that are in contact and are subjected to small oscillatory movements between them. Fretting causes a considerable reduction in fatigue str ength. In this paper recent knowledge on the short and long crack grow th behaviour is applied to estimate crack propagation and fatigue life in fretting. The model is based on mode I stress intensity factors wi th a threshold modified for short cracks. The predicted results are co mpared with experiments and the influence of the contact pressure is e xamined. A good correlation between predictions and experimental resul ts are obtained for crack growth rates as well as fatigue lives in ter ms of number of cycles to failure. It is seen that the increase of fat igue life observed for contact pressures above a certain level can be predicted by the crack growth model.