A quick and easy but comprehensive identification method for rotating asymmetry in rotating machines is proposed, based on the complex modal testing method. In this work it is shown that the reverse directional frequency response function (reverse dFRF), which indicates the degree of asymmetry, can be identified with a simple testing method requiring only a single vibration sensor and a single exciter. To clarify physical realization associated with estimation of the reverse dFRF, its relation to the conventional frequency response functions, which are defined by the real input (excitation) and output (vibration measurement), are discussed extensively.
LeeC. W.A complex modal testing theory for rotating machinery. Mech. Syst. and Signal Processing, 1991, 5(2), 119–137.
2.
LeeC. W.JohY. D.Theory of excitation methods and estimation of frequency response functions in complex modal testing of rotating machinery. Mech. Syst. and Signal Processing, 1993, 7(1), 57–74.
3.
JohY. D.LeeC. W.Excitation methods and modal parameter identification in complex modal testing for rotating machinery. Int. J. Analyt. and Expl Modal Analysis, 1993, 8(3), 179–203.
4.
LeeC. W.JohC. Y.Development of the use of directional frequency response functions for the diagnosis of anisotropy and asymmetry in rotating machinery: Theory. Mech. Syst. and Signal Processing, 1994, 8(6), 665–678.
5.
JohC. Y.LeeC. W.Use of dFRFs for diagnosis of asymmetric/anisotropic properties in rotor-bearing system. Trans. ASME, J. Vibr. and Acoust., 1996, 118, 64–69.
6.
LeeC. W.Vibration Analysis of Rotors, 1993 (Kluwer Academic Publishers, Dordrecht).
7.
LeeC. W.LeeS. K.An efficient complex modal testing theory for asymmetric rotor systems: Use of unidirectional excitation method. J. Sound and Vibr., 1997, 206(3), 327–338.
8.
GentaG.Whirling of unsymmctrical rotors: A finite elements approach based on complex co-ordinates. J. Sound and Vibr., 1988, 124(1), 27–53.
