Identification of nonlinearity of flow-induced vibration for structures having nonlinear property by using wavelet transform

This paper presents a nonlinear system identification for an elastically supported rigid cylinder in a cross flow. The cylinder is supported by a pair of elastic cantilever beams and a wire that adds nonlinearity to the system. Time history response of the vortex-induced vibration is measured experimentally. Joint time-frequency analysis based on wavelet analysis is applied to identify the nonlinear characteristics of the system. The time-frequency analysis is employed to the observed signal, and characteristics of the fluid-structure nonlinear coupled vibration are observed.