Schallamach waves in rolling: Belt drives

The contact mechanics in a belt drive has been experimentally studied to explore the mechanism of relative displacement at the belt/pulley interface. We have found that under the slow speed considered, no sliding takes place at the interface, and that relative displacement between the elastomeric belt and the pulley is achieved by cyclic detachment. The contact mechanics is different in the driver and driven pulleys, which results in different slip arc angles and calls into question the universal validity of the symmetric sliding-based approach to analysis of the belt drive contact. Waves of detachment are observed in the driver pulley, while in the driven pulley, the system instabilities result from the combination of the pulley rotation and the adhesion hysteresis.