Application of the time domain Fourier filter output (TDFFO) method to theidentification of a lightly damped non-linear system with an odd-spring characteristic

This paper presents a method for experimentally identifying the parameters of a lightly damped non-linear system with an odd restoring force, as repre sented by the Duffing equation. It requires only a single free vibration te st to determine the variation of the natural frequency with the decaying am plitude, and the identification procedure involves no approximation, as lon g as one can determine the system backbone curve accurately. A computer sim ulation and a laboratory experiment are used to demonstrate the method. (C) 2001 Academic Press.