Calculating Vortex-Induced Vibration of Bridge Decks at Different Mass-Damping Conditions

Abstract

An improved method for calculating the vortex-induced vibration (VIV) of bridges is proposed in this article. In this method, the nonlinear characteristics of the additional aeroelastic effects during VIV versus structural amplitude are first identified through an instantaneous identification method and polynomial fitting. The expression for the aeroelastic effects as a function of structural amplitude is then transformed to the function of structural velocity and/or displacement to calculate the limit-cycle oscillation of the deck. The proposed method was validated through an experiment with different mass-damping conditions. The results indicate that the generalized polynomial model with parameters identified on one particular mass-damping condition can be used to calculate the VIV response of the deck within a certain range of mass-damping values. Based on this method, the VIV performance of a real bridge was calculated by considering the influences of modal shape and spatial coherence of VIV forces. Compared with the traditional method, the applicability of which is limited to a particular mass-damping condition for which the model parameters were estimated, the proposed method will significantly reduce the uncertainty in the prediction of the VIV performance of a real bridge.