Abstract: The paper introduces a method for modal analysis using the wavelet transform, and discusses the possibilities of teh uncoupling of the system modal as well as the identification of time-varying parameters using the wavelet transform. In addition, the reasons why the Morlet wavelet is attractive in analyzing signals generated by dynamical systems is given, although there are a multitude of wavelets that could be used. Finally, based on the characteristics of transient responses and the Morlet wavelet, a family of wavelet functions is introduced and used in the simulation of modal analysis. The results are straightforward and satisfactory.

Key words: system of multidegree-of-freedom, time-varying system, modal uncoupling, modal parameters identification, wavelet transform