Friction-induced parametric resonances in discs: Effect of a negative friction-velocity relationship

Parametric resonances are studied which occur when an elastic system is rotated around an annular disc with friction having a negative slope with velocity. The elastic system consists of two spring-dashpots, in the transverse and in-plane (circumferential) directions, and a common point mass. The complete arrangement is driven around the disc through the in-plane stiffness and damper. It is demonstrated that the effect of the in-plane system (including the negative friction-velocity relationship) is (i) to introduce additional parametric resonances which are destabilised by the transverse damper, and (ii) to reduce the regions of instability of the other resonances.