WAVELET AND CHAOS ANALYSIS OF FLOW-INDUCED VIBRATION OF A SINGLE CYLINDER IN CROSS-FLOW

This paper attempts to shed some light on the characteristics of the f low induced vibration of an elastically mounted single cylinder in a c ross flow using the newly developed joint time-frequency analysis tech niques (JTFA) and in particular the modulated Gaussian wavelet. More s pecifically, the modulated Gaussian wavelet is chosen in the current w ork, since it was shown in [1] to be more effective than other well kn own wavelets in analysing the flow induced vibrations of a single cyli nder similar to the one under consideration. In the current work, this wavelet shows good evidence that the flow induced vibration process, in the range of system parameters considered, is most likely to underg o nonstationary, nonlinear and chaotic dynamics. It is found that for certain values of system parameters the nonlinearity may lead the syst em into chaos. Phase plane portraits, Poincare maps and fractal dimens ions have been used to confirm the chaotic behavior of the response of the system under investigation. (C) 1998 Elsevier Science Ltd. All ri ghts reserved.