TIME-FREQUENCY ANALYSIS WITH DIGITAL FILTER FOR NONLINEAR SYSTEM CHARACTERIZATION IN MECHANICAL VIBRATIONS

The aim of this study is to model and identify dynamics of mechanical systems from their vibration response during normal operation. To achieve this, we propose a time-frequency analysis procedure based on infinite impulse response digital filter technology. We discuss the time-frequency analysis of weakly nonlinear system, i.e., the Duffing equation for transient and non-stationary states including passage through resonance phenomena. We propose a basic concept for application of time-frequency analysis to nonlinear system characterization to model mechanical systems. Some experimental approaches are also given to confirm this.