Calculation method of bridge buffeting responses using an alternating frequency-time domain method

Authors describe an analysis of bridge buffeting response by using an alternating frequency-time domain(AFT) method.Since the wind loads include both the buffeting loads and the self-excited(motion-induced) loads of which the latter part is commonly defined by frequency domain flutter derivatives,the AFT method is introduced to employ the advantages of both domains by performing convolutions in the frequency domain and switching to the time-history to evaluate the nonlinear forces as functions of the state trajectory and structural coupling between different modes;moreover,taking advantage of the pseudo-force concept,coupled self-excited terms are easily incorporated in time-history.The AFT algorithm makes this approach computationally advantageous.Through an example bridge,the validity and efficiency of the presented method are confirmed.