Identification Techniques in Rotordynamics
In order to find out the condition of a rotating machine during operation usually vibrations (output signals) are measured at specified machine locations. Indications can be determined from these signals, which allow a diagnosis of possible failures (fault parameters) based on the support of expert knowledge and/or good rotordynamic models. However, the success of failure diagnostic would probably be much better, if in addition to the output signals more information would be available about rotor excitation forces. This leads to the idea of using Identification Techniques with measured input and output signals. Frequency response functions can than be calculated and an extraction of physical and/or modal parameters, expressing the actual system condition, is possible. This contribution describes the basic relations of Identification Techniques in rotordynamics, including rotordynamic models, measurement and excitation methods and parameter estimation procedures. Some applications of parameter identification are presented together with the corresponding test procedures and test apparatus.
KeywordsIdentification Technique Modal Parameter Frequency Response Function Fault Parameter Magnetic Bearing
Unable to display preview. Download preview PDF.
- /1/.Morton, P.G.: “The Derivation of Bearing Characteristics by Means of Transient Excitation applied directly to a Rotating Shaft”, IUTAM-Symposium, Dynamics of Rotors, Lyngby Denmark, Springer Verlag 1975, pp. 350–370.Google Scholar
- /2/.Nordmann, R., Schöllhorn, K.: “Identification of Modal Parameters of an Elastic Rotor with Oil Film Bearings”, Journal of Vibrations, Acoustics, Stress, and Reliability in Design, 1984, Vol. 106.Google Scholar
- /3/.Tonnesen, J., Lund, J.: “Experimental Techniques for Rotordynamic Analysis, CISM Course No. 297, Rotordynamics 2, Ed. by N.F. Rieger, Springer-Verlag, 1988.Google Scholar
- /4/.Muszynska, A., Bently, D.: “Modal Testing and Parameter Identification of Shaft/Fluid Lubricated Bearing System. IV Int. Modal Analysis Conference, Union College, Schenectady, NY, Los Angeles, CA, February 1986.Google Scholar
- /5/.Kanki, H., Kawakami, T.: “Experimental Study on the Dynamic Characteristics of Pump Annular Seals”, Vibr. in Rotating Machinery IMechE Conf., York, 1984.Google Scholar
- /6/.Nordmann, R., Matros, M., Neumer, T.: “Parameter Identification in Rotating Machinery by Means of Active Magnetic Bearings”, IFTOMM, 4th Int. Conference on Rotor Dynamics, Chicago, Illinois, 1994.Google Scholar