The robustness of an experimental procedure to predict the stability threshold speed in rotating machinery

High speed rotating machinery, with an operating speed above the first critical speed or above the first resonance frequency, is sensitive to instability. In this research, the robustness of an experimental procedure to predict the stability threshold speed in rotating machinery is discussed. The single degree of freedom model that is used in the experiments is discussed and the procedure is experimentally validated on a rotating damping setup. In this setup, the rotating damping is varied by means of tightening and loosening a flexible coupling. It is shown that it is possible to predict the stability threshold speed experimentally and that the rotor becomes unstable above this speed