Analysis of the fretting conditions in a contact between an epoxy thermoset and a glass counterface

The fretting conditions in a contact between an epoxy thermoset and a glass counterface have been investigated using a specific device which allows in situ observation of the contact area. The critical displacement for transi tion from partial slip to gross slip conditions was investigated by the in situ detection of the micro-displacements and by the analysis of the fretti ng loops. Experimental results were in good relation with the theoretical p redictions derived from Mindlin's approach of incipient sliding. Depending on the loading conditions, a progressive change from gross slip to partial slip conditions was found to occur during the early stages of the fretting loading, i.e., before the appearance of any macroscopic damage such as crac king or particle detachment. These fretting conditions were synthesized in a fretting map giving the boundary between various fretting regimes as a fu nction of the normal load, the imposed displacement and the number of cycle s.