
170 Friction-Induced Vibration and Self-Organization
Nosonovsky and Adams (2001) investigated the interaction of elastic body
waves with frictional sliding. They showed that the phenomenon of elastic
waves radiated from a sliding interface also exists in the general case of two
elastic bodies in sliding contact. Each wave moves at a different angle with
respect to the interface such that the trace velocities along the interface are
equal and supersonic with respect to both media. This supersonicity does
not violate causality as it is only the trace velocity that is supersonic; the
waves move at the dilatational and shear wave speeds in thei