A B S T R A C T This work describes the application of multiaxial fatigue criteria based on critical plane and mesoscopic (Dang Van, 1973, Sciences et Techniques de lÁrmement, 47, 647-722) approaches to predict the fatigue initiation life of fretted components. To validate the analysis, several tests under closely controlled laboratory conditions are carried out in a Ti6Al-4V alloy. These classical Hertzian tests reveal a size effect where fretting fatigue lives vary with contact size. Experimentally available data for fretting fatigue of an Al-4Cu alloy are also used to assess the models. Neither the critical plane models nor the mesoscopic criterion considered can account for the effects of different contact stress fields on the initiation life, if the calculation is based only on highly stressed points on the surface. It is shown, however, that satisfactory results can be achieved if high values of the fatigue parameters are sustained over a critical volume.

This work aims to develop a fretting crack initiation threshold methodology based on the application of high cycle fatigue (HCF) multiaxial models. The proposed methodology considers the use of multiaxial stress based models, which define safe and damage zones in an appropriate stress space, associated with a volume-averaging procedure. The methodology proved satisfactory in estimating the fretting fatigue limit of simple experiments using cylindrical contacts and was also able to capture the size effect phenomenon present in such tests.