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Experimental characterisation of asynchronous partially contacting motion in a multiple-degree-of-freedom rotor system
,
Michael Friswell,
Alan R. Champneys
Mechanical Systems and Signal Processing, Volume: 145, Start page: 106904
Swansea University Authors:
Rafael Sanchez Crespo, Alexander Shaw , Michael Friswell
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Copyright 2020 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.
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DOI (Published version): 10.1016/j.ymssp.2020.106904
Abstract
Recent theory has predicted the onset of asynchronous bouncing motion at speeds beyond those of internal resonance in multi-degree-of-freedom rotating systems with intermittent contact. This paper provides the first attempt to experimentally validate the theory. Vibrations incorporating rotor-stator...
| Published in: | Mechanical Systems and Signal Processing |
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| ISSN: | 0888-3270 |
| Published: |
Elsevier BV
2020
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| Online Access: |
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| URI: | https://cronfa.swan.ac.uk/Record/cronfa54129 |
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| Abstract: |
Recent theory has predicted the onset of asynchronous bouncing motion at speeds beyond those of internal resonance in multi-degree-of-freedom rotating systems with intermittent contact. This paper provides the first attempt to experimentally validate the theory. Vibrations incorporating rotor-stator contact are recorded from a vertically ounted rotordynamics test rig comprising two rigid shaft-disk assemblies that are axially joined by a bellows coupling. The upper rotor has an elastic bearing whereas the lower one is free but has a snubber ring located on its lower shaft, with clearance about 2.5% of the entire system’s length. Nonlinear vibrations are excited by a small measured eccentricity of about 20% of the clearance. Measurements are taken by a wireless accelerometer and processed to produce an experimental bifurcation diagram, for small steps in the rotor speed, allowing the transients to decay. Evidence is found of bistability between quiescent and violent motion over a wide range of rotational speeds, including those representing both fundamental and internal resonances. The results are shown to qualitatively match numerical simulations from a differential equation model that incorporates rigid impacts. |
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| Keywords: |
Rotordynamics, Nonlinear dynamics, Experimental testing, Internal resonance, Rotor-stator impact, Asynchronous bouncing motion |
| College: |
Faculty of Science and Engineering |
| Funders: |
UKRI, EP/K003836/2 |
| Start Page: |
106904 |