How does rubber truly slide between Schallamach waves and stick–slip motion?

Abstract

Abstract Schallamach waves have been investigated from a new viewpoint of their dynamic behaviour. Two new insights were introduced to elucidate the mechanism of the initiation and propagation of the wave of detachment, firstly the surface interaction force can produce a meniscus effect at the rubber surface and secondly the stick–slip motion can be seen to have a significant role during the sliding of rubber. The meniscus could perhaps be a source of the initiation of the wave of detachment at the leading edge and might have a role to play in the peeling of the rubber away from the trailing edge of the contact simultaneously. The characteristics in the propagation of the waves such as their frequency, their high progression velocity and the sliding velocity dependence all correlate with the periodic stick–slip motion. True finite sliding was observed to take place during a slip stage in the stick–slip motion whether waves of detachment appear or not on the contact area. Thus, the contribution of the waves to the frictional sliding of rubber is to decrease the contact area before true sliding and allow smoother sliding with less vibration of stick–slip motion to occur during rubber friction.