Estimation of nonstationary crosswind response of tall buildings with nonlinear aeroelastic effect

This study addresses analysis of the crosswind response of tall buildings under nonstationary wind excitations. The wind load under nonstationary wind excitation was quantified using the force parameters under stationary wind, but the effect of the time-varying mean wind speed was considered in a quasi-stationary manner. For buildings without consideration of nonlinear aerodynamic damping, the evolutionary spectral analysis approach and statistical moment equation approach are presented, which provide analytical solutions of time-varying response standard derivation (STD), extreme response, and fatigue damage. For buildings with consideration of nonlinear aerodynamic damping, the governing equations of statistical moments of the building motion including time-varying STD, or variance/covariance, and kurtosis of response were established and solved using the non-Gaussian moment closure technique. The higher-order moments involved were estimated from a kurtosis-based translation process model. Narrowband response characteristics were applied to simplify the non- Gaussian closure approach. The nonstationary extreme response and fatigue damage were further estimated from time-varying STD and kurtosis of response. The effectiveness of the analysis framework was examined through comparison with a response time history simulation. The characteristics of the crosswind response under nonstationary excitations are also discussed.