Experimental observations on rotor-to-stator contact

If a flexible rotor contacts its stator, the nonlinearities induced by contact may result in a great variety of vibration phenomena. The motion types reported and analyzed in the literature include rotor synchronous motions, forward and backward whirl, sub- and superharmonic motions, motions including sidebands as well as chaotic motions. This article presents an integral experimental approach based on a modular kit for rotordynamic experiments. The experimental results confirm the motion patterns listed above. The underlying fundamental phenomena are analyzed and discussed based on resonance diagrams from run-up and run-down processes, orbit plots and frequency spectra. Emphasis is put on sensitive system parameters and on existence and stability of the various types of motion. (C) 2019 Elsevier Ltd. All rights reserved.