Influence of running-in in dry and wet conditions on the interfacial adhesion of tire tread rubber

To study the running-in effects on the adhesion properties of tire tread compounds, an approach is proposed based on theoretical analysis of experimental load-distance curves. The approach uses the Maugis model of adhesion in an axisymmetric elastic contact. Classical AFM tests with a ball of 450 nm glued to the probe are performed for two different surfaces of the tire tread rubber after running-in in dry and wet friction regimes and for the original rubber surface. It is shown that running-in in wet conditions decreases the surface energy of rubber. Also, running-in in both wet and dry conditions leads to softening of a surface layer of rubber.