An evaluation of the competition between wear and crack initiation in fretting conditions for Ti-6Al-4V alloy

The fretting process can lead to material removal (wear), nucleation and propagation of cracks (fatigue), or both. In the first step, the aim of the present paper is to investigate the influence of non-linear behaviour on the wear profiles, in order to evaluate the role of plasticity under different slip regimes for a cylinder-on-flat contact fretting wear. The material of the study is a classical titanium alloy, Ti-6Al-4 V (noted TA6V in the following) that is represented by a von Mises equivalent stress, and a combination of non-linear kinematic hardening and isotropic hardening. Since wear is not the only damage mechanism, crack propagation is also considered in the second step. The competition between wear and crack initiation is investigated, thanks to two types of fatigue criteria, purely stress dependent models (Dang Van and Crossland), and a stress-strain dependent fatigue model (Smith-Watson-Topper). The contact evolution influences fretting crack nucleation. The objective is to determine the relevant fatigue criterion and compare the numerical results to the experimental fretting map.