Vibration of a Misaligned Rotor System with Asymmetric Shaft Stiffness

Abstract:

Vibration characteristics of a misaligned rotor with asymmetric shaft stiffness are studied. The system consists of two shafts connected by a flexible coupling with parallel misalignment, two rigid disks attached at the middle of each shaft and one of the shafts has asymmetric stiffness. The governing ordinary differential equations are derived using Lagrange dynamics and integrated through numerical methods. The effects of asymmetry, eccentricity and misalignment are studied through the peak-to-peak lateral vibration amplitude at different rotor speed. Simulation results show that the amplitude peaks at the natural frequency associated with unbalance and parallel misalignment, while half the natural frequency associated with the asymmetric shaft stiffness. This study may contribute to enrich understanding of the vibration of a rotor system under the cases of eccentricity, parallel misalignment and asymmetric shaft stiffness.

• Periodical: Advanced Materials Research (Volumes 503-504)
• Pages: 813-818
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.503-504.813
• Online since: April 2012
• Authors: Sheng Feng, Hai Peng Geng, She Miao Qi, Lie Yu
• Keywords: Asymmetric Shaft Stiffness, Flexible Coupling, Parallel Misalignment, Vibration

References

[1] A. Tond: Some problems of rotor dynamics (Prague: Publishing Housing of the Czechoslovak, Academy of Science, 1965).

[2] J. Clinton: Lateral-torsional vibration of a side–loaded rotor with asymmetric shaft stiffness, dissertation. The California Poly State University, San Luis Obispo, (2010).

DOI: 10.15368/theses.2010.68

[3] Wu Xi, J. Meagher: A two-disk extended Jeffcott rotor model distinguishing a shaft crack, from other rotating asymmetries . International Journal of rotating machinery, 2008, pp.1-11.

DOI: 10.1155/2008/846365

[4] Sudhakar G N D S, A. S. Sekha: Coupling misalignment in rotating machines: modeling, effects and monitoring. Noise & Vibration Worldwide Vol. 40 (2009), pp.17-39.

DOI: 10.1260/0957-4565.40.1.17

[5] Liu Zhansheng, Zhao Guang, Long Xin: Survey of the research on coupling with misalignment of rotary machinery. Turbine Technology Vol. 49 (2007), pp.321-325.

[6] A .W. Lees: Misalignment in rigidly coupled rotors. Journal of Sound and Vibration Vol. 305(2007), pp.261-271.

DOI: 10.1016/j.jsv.2007.04.008

[7] Hussain AI K. M: Dynamic stability of two rigid rotors connected by a flexible coupling with angular misalignment. Journal of Sound and Vibration, Vol. 266(2003), pp.217-234.

DOI: 10.1016/s0022-460x(02)01627-9

[8] Hussain AI K. M, Redmond I: Dynamic response of two rotors connected by a mechanical coupling with parallel rigid misalignment. Journal of Sound and Vibration Vol. 249(2002) , pp.483-498.

DOI: 10.1006/jsvi.2001.3866

[9] Li Ming: Nonlinear dynamic behavior of parallel-misaligned rotor system. Journal of mechanical strength Vol. 27 (2005), pp.580-585, in Chinese.