Modal Identification Based on Hilbert Transform for Time-Varying System
Modal identification methods based on the Hilbert Transform are applied to identify modal parameters of time-varying system using impulse response time histories. First, the response data are decomposed into modal responses through the empirical mode decomposition (EMD). Then, the Hilbert transform is applied to each modal response to obtain the instantaneous frequencies. The applications of the proposed methods are illustrated using a 3 degree-of-freedom (DOF) systems with time-varying dynamic characteristics. Numerical simulation results demonstrate that the proposed system identification methods yield good results.
Chunliang Zhang and Paul P. Lin
M. Zheng and F. Shen, "Modal Identification Based on Hilbert Transform for Time-Varying System", Applied Mechanics and Materials, Vols. 226-228, pp. 303-307, 2012