Vibration analysis based on time-frequency analysis with digital filter

Abstract

The main purpose of the current study is to model and identify vibrations in mechanical systems subject to arbitrary external excitations. In this paper, we propose a method based on infinite impulse response digital filter technology - termed time-frequency analysis - to analyze transient and steady-state vibrations. Firstly, we introduce the time-frequency analysis procedure and the algorithm to implement this procedure. Secondly, we analyze typical discrete signal inputs such as impulse, sinusoidal and swept sine signals, and present time-frequency characteristics for transient and steady-state signals. Thirdly, we apply our analysis method to the mechanical vibration behavior of a single- degree-of-freedom system subjected to various types of external excitations. The results of our analysis for steady-state vibration are verified as being equivalent to those from a fast Fourier transform (FFT) analysis. Moreover, the proposed analysis has the advantage over FFT analysis that we can also analyze transient vibration phenomena. © 2013 The Japan Society of Mechanical Engineers.