Modification of Friction-Induced Instability in a Disk System Through Dither Excitation Forces

This paper employs a continuous rotor model and a contacting SDOF system to examine dither’s role in stabilizing friction-induced oscillations. The disc rotor is modeled by a thin, clamped-free annular plate. Under the action of tangential dither, the frictional contact load is represented by a sinusoidally-varying follower force. The stability of the combined system, with and without dither signals, is assessed using multiple-scale analysis and Floquet theory. It is shown that dither is capable of quenching instabilities at some rotor speeds while at the same time producing new instabilities at other rotor speeds. The results suggest that one mechanism by which dither can suppress squeal is by changing the rotor speeds at which squeal vibrations occur.