Abstract：Parameter identification for time-varying vibration system and typical nonlinear vibration system are conducted by using Morlet wavelet transform method in this paper. Firstly, the wavelet ridge of vibration response is extracted by Morlet wavelet transform, and then the instantaneous frequency and instantaneous amplitude are obtained. Afterward, the nonlinear damping and stiffness coefficient are estimated according to least squares curve fitting. The time-varying damping free vibration system, the duffing damped nonlinear harmonic vibration system, and the Van der Pol nonlinear free vibration system are taken for example to show the effectiveness of wavelet transform method for identifying time-varying vibration system and nonlinear vibration system.
2014, Vol. 33 
