Dynamics in sliding friction of soft adhesive elastomer: Schallamach waves as a stress-relaxation mechanism

This study investigated the effects of Schallamach wave (SW) propagation on macroscopic frictional behaviors. The temporal changes in the friction force that acts on the sliding interface between a rubber block made of cross-linked polydimethylsiloxane (PDMS) and a cylinder made of polymethyl methacrylate (PMMA) were monitored. Simultaneously, in-situ observation of the sliding interface was performed with a total reflection optical system. Through experiments, three types of sliding modes were observed: stick-slip (SS) resulting from SW propagation (SS-SW), SS resulting from large bulk deformation (SS-BD), and steady sliding without SS (non-SS). The effect of the normal load on the SS behavior was also investigated.