ABSTRACT
During wear by fatigue of tyre materials, the material at the surface of the tyre tread undergoes thermomechanical solicitations cycles each time the wheel turns. The presence of a damage gradient at the sub-surface of the material is a consequence of the wear mechanism by fatigue. We here report a novel way to detect and quantify the damage gradient due to fatigue wear in poly(ethyl acrylate) multiple networks. At the molecular scale, confocal microscopy observations of the fluorescence of the mechanophores show a highly localised damage in a 10μm deep area under the surface of the material. We evidence a 2-step damage mechanism of damage accumulation in the sub-surface, followed by erosion of the material. Our observations shed new lights on the underlying mechanisms of frictional wear in soft elastomer materials.
