Friction-induced vibration of an elastic disc and a moving slider with separation and reattachment

The transverse vibration of an elastic disc, excited by a preloaded mass-damper-spring slider dragged around on the disc surface at a constant rotating speed and undergoing in-plane stick-slip oscillation due to friction, is studied. As the vertical vibration of the slider grows at certain conditions, it can separate from the disc and then reattach to the disc. Numerical simulation results show that separation and reattachment between the slider and the disc could occur in a low speed range well below the critical disc speed in the context of a rotating load. Rich nonlinear dynamic behaviour is discovered. Time-frequency analysis reveals the time-varying properties of this system and the contributions of separation and in-plane stick-slip vibration to the system frequencies. One major finding is that ignoring separation, as is usually done, often leads to very different dynamic behaviour and possibly misleading results.