Fretting is now fully identified as a small amplitude oscillatory motion which induces aharmonic tangential force between two surfaces in contact. It is related to three main loadings, i.e.fretting-wear, fretting-fatigue and fretting corrosion. Three fretting regimes will be considered:stick regime, slip regime and mixed regime. Obviously the partial slip transition develops thehighest stress levels which can induce fatigue crack nucleation depending on the fatigueproperties of the two contacting first bodies. Therefore prediction of the frontier between partialslip and gross slip is required
