Rotating Cantilever: Escape Dynamics for Different Noise Perturbations

Abstract In rotating machinery, large amplitude vibrations can result in increased wear and reduced system life. These vibrations can be a result of response localization, which can result in localized vibrations. It is of interest to explore means to reduce such vibrations in these systems. As a step towards attenuating vibrations, the use of noise to steer the system away from a large amplitude response state is explored in this work. With potential application in turbomachinery in mind, the influence of different noise perturbations is considered. The noise models considered include Gaussian white noise, one based on forcing amplitude modulation, and another based on turbine engine spectral data. An experimental test rig with a rotating cantilever and an arrangement of magnets is considered. This cantilever system, which has softening behavior, has multiple response states. Noise perturbation-induced movement from a large amplitude response state to a low amplitude response state of this rotating cantilever is examined. To explain experimental observations and support them, numerical studies are pursued. The experimental and numerical results for escape times are compared and discussed. The findings from this work are expected to be relevant to noise-induced transitions in other physical systems.