Influence of Time-Varying Mean Winds on the Nonlinear Buffeting Responses of a Super Long-Span Suspension Bridge

The cosine function and two modulation functions are separately selected to generate the time- varying mean wind and fluctuating wind speed, and their effects on nonlinear buffeting responses of a super long-span suspension bridge were investigated in this paper. Firstly, two non-stationary wind speeds models were validated by the classical power spectrum density, and could effectively simulate the non-stationary characteristics. Secondly, the time histories and RMS values of three displacement responses of the bridge deck under two non-stationary wind speeds with three different values of 𝛾𝛾 and 𝜃𝜃 were compared, respectively. Results show that the torsional and lateral displacement responses under the non-uniform modulation function are larger than those under the uniform modulation function. Moreover, the RMS values in three displacement responses of the deck gradually become larger with the increase of 𝛾𝛾 or the decrease of 𝜃𝜃.