Magnetic Bearings for Non-Destructive Health Monitoring of Rotating Machinery Supported in Conventional Bearings


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This paper describes initial results from a project expanding the field of rotor health monitoring by using Active Magnetic Bearings (AMBs) as actuators for applying a variety of known force inputs to a spinning rotor in order to monitor and evaluate response signals resulting from these inputs on-line. Similar to modal analysis and other nondestructive evaluation (NDE) techniques which apply input signals to static structures in order to monitor responses; this approach allows for the measurement of both input and output response in a rotating system for evaluation. However, unlike these techniques, the new procedure allows for multiple forms of force input signals to be applied to a rotating structure. This technique is being developed for use on rotating equipment supported in conventional bearings where an AMB actuator is added to a system for improved health monitoring. This paper presents initial results from this project including a demonstration of the system identification capability of the procedure during the commissioning of a test rig, and a summary of a technique developed for identifying breathing-cracks in rotors using the new technique.



Key Engineering Materials (Volumes 293-294)

Edited by:

W.M. Ostachowicz, J.M. Dulieu-Barton, K.M. Holford, M. Krawczuk and A. Zak




M. Kasarda et al., "Magnetic Bearings for Non-Destructive Health Monitoring of Rotating Machinery Supported in Conventional Bearings", Key Engineering Materials, Vols. 293-294, pp. 383-390, 2005

Online since:

September 2005




[1] A.D. Dimarogonas: Engineering Fracture Mechanics Vol. 55 (1996), p.831.

[2] R.C. Eisenmann, Sr. and R.C. Eisenmann Jr.: Machinery Malfunction Diagnosis and Correction, (Prentice-Hall, Upper Saddle River, NJ, 1998).

[3] R.L. Eshleman: Detection, Diagnosis and Prognosis: An Evaluation of Current Technology, Proceedings MFPG 44, Vibration Institute, (1990).

[4] R. Gasch: Journal of Sound and Vibration Vol. 160 (1993), p.313.

[5] R.W. Hope, L.P. Tessier, C. Knospe and T. Miyaji: Adaptive Vibration Control of Industrial Turbomachinery, 98-GT-405, (1998).

[6] R.R. Humphris: Proceedings of MAG '92, Magnetic Bearings, Magnetic Drives, and Dry Gas Seals Conference & Exhibition, Alexandria, VA, p.123.

[7] T. Iwatsubo and S. Arii: Proceedings of ImechE Conference, 1992, paper #C432/093, p.275.

[8] M.E.F. Kasarda, P.E. Allaire, R.R. Humphris and E.J. Gunter: ASME, DE-Vol. 37, September 1991, p.245.

[9] G. Mani, D. Quinn, T. Bash, M. Kasarda, D. Inman and R.G. Kirk: Conference Proceedings, 9th International Symposium on Magnetic Bearings (ISMB9), Lexington, KY, Aug3-6, (2004).

[10] H. Mendoza, Evaluation of the Effectiveness of an Active Magnetic Damper (AMD) in Damping Subsynchronous Vibrations in a Flexible Rotor, (Virginia Tech MS Thesis 2000).

[11] J.D. Mitchell, Introduction to Machinery Analysis and Monitoring, (Penn Well Publishing, Tulsa, OK, 1993).

[12] A.H. Nayfeh and D.T. Mook: Nonlinear Oscillations. (John Wiley & Sons, Inc., NY, 1979).

[13] C.A. Papadopoulos and A.D. Dimarogonas: Journal of Vibrations and Acoustics Vol. 114 (1992), p.461.

[14] H.C. Pusey: Proc. 11th Biennial Conference on Reliability Stress Analysis and Failure Prevention, ASME, (1995).