The instability in disc with frictional follower load rotating at subcritical speed were investigated by multiple time scale approach. Due to the frictional follower load rotating at constant angular speed around a stationary, plane and annular plate, the plate with only an arbitrary small force was found to be unstable when a nodal diameter mode was present. The rotating follower proved to destabilize all the backward travelling waves of nodal diameter modes. In terms of speed rotation, instability was found not to be affected.
Chan, S. N., Mottershead, J. E., & Cartmell, M. P. (1995). Instabilities at subcritical speeds in discs with rotating frictional follower loads. Journal of Vibration and Acoustics, 117(2), 240-242. https://doi.org/10.1115/1.2873936