Journal article 160 views
Backbone analysis for nonlinear vibrations in rotor dynamics
Alexander Shaw 
,
MEHMET AKAY,
Michael Friswell
,
MEHMET AKAY,
Michael Friswell
Nonlinear Dynamics, Volume: 114
Swansea University Authors:
Alexander Shaw , MEHMET AKAY, Michael Friswell
DOI (Published version): 10.1007/s11071-026-12466-z
Abstract
Backbone curves are a well established practice for understanding the vibrations of nonlinear structures, by charting the frequency-amplitude relations for the underlying conservative system. However, in their typical form they are ineffective in tracing many of the phenomena seen in the lateral vib...
| Published in: | Nonlinear Dynamics |
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| Published: |
2026
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| URI: | https://cronfa.swan.ac.uk/Record/cronfa71666 |
| Abstract: |
Backbone curves are a well established practice for understanding the vibrations of nonlinear structures, by charting the frequency-amplitude relations for the underlying conservative system. However, in their typical form they are ineffective in tracing many of the phenomena seen in the lateral vibrations of an isotropically supported rotating disk, which include both periodic, quasiperiodic and isolated responses. This is because the underlying conservative system lacks mechanisms to drive the mode locking that is an essential part of these responses. However, to include effects such as unbalance forcing that can induce these behaviours would reduce the generality of the analysis, and may also require knowledge of parameters that can be difficult to control or measure. This work produces backbone curves with additional constraints to ensure that the response remains in phase with the unbalance forcing, acting in the place of the physical causes of mode locking. These curves provide a skeleton that sits underneath the bifurcation diagrams of a wide range of nonconservative and also weakly anisotropic rotating disc systems, despite being calculated with just the underlying conservative and isotropic parts of the system. This allows a systematic means of exploring the complex response space of rotating systems, enabling continuation approaches to efficiently find isolated response regions that previously required a sweep of many time simulations to discover. The approach provides some commonality to the analysis of a diverse range of responses. The method is demonstrated on an isotropic 2 degree of freedom overhung rotor with a smooth radial stiffness nonlinearity, but is shown to have relevance to nonsmooth systems and weakly anisotropic systems. An experimental comparison is also given. |
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| College: |
Faculty of Science and Engineering |