Nonlinear Modal Interactions during Rub-Impact of a Rotating Flexible Shaft

A Kartheek, K Vijayan (Indian Institute of Technology Kharagpur, India) & MI Friswell (Swansea University)

Journal of Vibration and Control, Vol. 29, No. 7-8, April 2023, pp. 1554-1563

An understating on interaction between a rotating flexible member and a stationary element has wide range of industrial application. The focus of this study was to understand the modal interactions using a conceptual model. The conceptual model of the system consists of multiple disc rotor with a localised conduit. A theoretical model of the system was developed using finite element analysis. An eigenvalue analysis was carried out on the system and a Campbell diagram of the system was developed. The Campbell diagram provided information about the rotor speed wherein synchronization with the whirling modes occur. Further a reduced order non-linear contact model was developed. A numerical bifurcation analysis with rotor speed as parameter was carried out on the reduced model. Analysis was carried out using randomized initial condition for each rotation speed. During the bifurcation study certain rotation speed produced high whirling response at speeds different from the critical speed. The increase in response was associated with the internal resonance of whirling modes and rotor speed. The participating modes were identified using the Campbell diagram and full spectrum. The results from the theoretical model was validated using an experimental test rig. The identification of these internal resonance rotor speed can be useful in identifying the rotor speed exclusion zone and thereby improve the rotor life.

Paper Availability

This material has been published in Journal of Vibration and Control, Vol. 29, No. 7-8, April 2023, pp. 1554-1563. Unfortunately the copyright agreement with Sage does not allow for the PDF file of the paper to be available on this website. However the paper is available from the journal website - see the link below.

Link to paper using doi: 10.1177/10775463211066406

Journal of Vibration and Control