基于HFFB试验的结构广义荷载与风振响应分析

采用高频测力天平风洞试验技术得到的结构基底弯矩和扭矩进行结构风振响应分析时,只能考虑横向线性振型和扭转向常数型振型,忽略了结构高阶振型对结构响应的贡献。在分析高频测力天平风洞试验测试数据的基础上,以修正线性(常数型)振型广义荷载谱方法为依据,推导得到了结构横向和扭转向各阶振型广义荷载谱。同时,利用此各阶振型广义荷载谱进行了3种典型的格构式高耸结构气弹模型风振响应评估。通过比较气弹模型风洞试验结果和计算结果可知,当考虑振型修正、高阶振型和气动阻尼比后,计算结果与试验结果吻合较好,验证了推导得到的高阶振型广义荷载谱的准确性。

Analysis of Generalized Force and Wind-Induced Responses of Structures Based on High Frequency Force Balance Wind Tunnel Tests

The wind induced dynamic responses can be analyzed by applying the base bending overturning moment in sway directions and the base torque in the torsional direction measured by the high-frequency force balance (HFFB) technique in wind tunnel. Generally, only the effects of the first mode in each direction (two sway and one torsional directions) can be considered. However, the contribution of the higher order modes cannot be considered. In the present study, a framework for evaluating the generalized force spectra of the higher order modes in the sway and torsional directions is proposed according to the correction method of the generalized force spectra of the ideal mode shape. The data used in the analysis are measured through the HFFB wind tunnel tests. Then, the evaluation of the wind-induced dynamic responses of the aeroealstic model for three typical lattice high rise structures are presented by applying the proposed framework. The calculation results with considering mode shape corrections, higher order mode shape generalized force, and aero-dynamic damping ratios, agree well with those from the wind tunnel tests. This verifies the accuracy of the framework for evaluating the different order mode shape for the generalized force spectra.