Wavelet-based Frequency Response Function for time-variant systems-An exploratory study

A wavelet-based Frequency Response Function (FRF) is proposed for vibration analysis of systems with time-varying parameters. The classical FRF is extended to a representation in the combined time-frequency domain using wavelet analysis. Time averaging is performed on the initial FRF to improve signal-to-noise ratio. It is shown that use of the wavelet ridge algorithm is effective in extracting and representing visually data from wavelet-based FRFs. The wavelet-based FRF is demonstrated on selected time-variant simulated lumped parameter systems and one experimental vibrating system. (C) 2013 Elsevier Ltd. All rights reserved.