Proposal of nonlinear buffeting analysis framework for long-span bridges using Volterra series-based non-stationary wind force model

This paper presents a nonlinear framework to simulate the buffeting response of long-span bridges under Typhoon winds by using a Volterra series-based wind force model. First, the non-stationary wind fields are generated around the bridge using evolutionary power spectrum of the measured wind speeds. Subsequently, the nonlinear buffeting load model is formulated in time-domain by employing the Volterra series. Then, these Volterra kernels are identified from flutter derivatives. At last, the wind forces are applied to 3D fishbone finite element model of a suspension bridge and nonlinear buffeting analysis is performed. The time history analysis results show a good agreement in the simulation of Typhoon-induced buffeting response when compared with the measurement data of bridge displacements. Also, the analysis results are compared with the simulation results obtained from the existing wind load models to show the efficacy of the proposed framework.