Effects of Disk Flexibility on Shaft Whirl Stability

Abstract

The effects of disk flexibility on the critical speeds of flexible shaft-disk systems is investigated by the method of Liapunov. The model consists of a flexible, continuous disk rigidly attached at an arbitrary location along a flexible, continuous shaft which is mounted on short, end bearings. Whirl speed stability boundaries are presented as functions of the disk flexibility parameter. These boundaries reduce to the limiting case of a shaft containing a concentrated mass at the point of disk attachment when the disk’s stiffness is very small, and approach the limiting case of an elastic shaft supporting a rigid disk as the stiffness increases.