  In this work, the crack nucleation under fretting loading is investigated
experimentally with a damage tolerant 2024 aluminium alloy. A new method is
introduced to determine its condition with respect to all loading parameters
including the number of fretting cycles. Further work deals with the prediction
of this threshold using the Smith-Watson-Topper criterion. New developments are
presented, in particular a process volume of variable size is introduced in the
computations of the fretting crack initiation.
