The effect of external damping on the vibration of flexible shafts supported on oil-film bearings

This paper discusses the use of intermediate, externally applied damping as a means of controlling the synchronous response of a flexible shaft supported on oil-film bearings. A method of finding the optimum magnitude of the external damper, and its optimum position, is described, which exploits the existence of “fixed points” on the amplitude-frequency response curves. The theoretical conclusions are supported by experimental results obtained from a uniform shaft carried on two oil-film bearings.