ABSTRACT
Tyre tread compounds are subjected to complex deformations throughout their life. The detailed loading cycles depend upon variables such as driving style, vehicle dynamics and the condition of the road surface. This work investigated the degradation of a tyre tread compound subjected to shear sliding against a representative road surface. Tests were performed under a range of different sliding friction deformation modes using a typical styrene-butadiene rubber (SBR). The compound was evaluated using an Instron ElectroPuls (E10000) to evaluate the degradation of the rubber as a function of time and mechanical input. Tests were carried out using a set load and varying sliding speeds to examine the dissipated energy between the simulated road surface and the rubber compound. Optical microscopy techniques showed changes in the compound surface structure at higher sliding speeds resulting in a modified surface layer and higher wear-debris build-up. These factors were noted to reduce the frictional energy after longer loading cycles. The mechanical deformation on the abrasion, heat build-up and thermal degradation of the compound are also discussed and allow for a deeper understanding of how wear and surface friction are developed in service.
