超高层建筑气动弹性效应双向受迫振动风洞试验研究

通过双向受迫振动风洞试验对高347m的长沙世茂广场模型的气动弹性效应进行研究，模拟结构平面两个轴向的一阶振动，同步测量了振动模型上的表面风压和模型顶部位移。在对振动模型横风向和顺风向的气动弹性力分析基础上，识别了该模型气动阻尼比和气动刚度比，计算并分析了气动弹性效应对结构风致响应和等效风荷载的影响。分析结果表明，在100年重现期风速作用下，该模型气动阻尼比为正值，气动刚度为负，气动刚度相对于结构刚度较小，对结构自振频率影响不大。考虑气动弹性参数后，顶部最大位移响应可减小5%，最高居住层最大加速度响应可减小10%，由等效风荷载计算得到的基底总剪力和基底总弯矩减小1.1%左右。分析表明，双向受迫振动风洞试验是一种有效且有实用前景的超高建筑气动弹性参数识别方法。

Investigation on wind-induced aero-elastic effects of super high-rise building by bi-axial forced vibration wind tunnel test

Aero-elastic effects of Changsha Shimao Plaza were analyzed by bi-axial forced harmonic vibration wind tunnel test，which simulated the first-order bi-axial vibration of the structure, and the surface pressure of the vibration model and displacement at the top of the model were also synchronously measured. The aerodynamic damping ratio and aerodynamic stiffness were identified based on the analysis of the aero-elastic force on the vibration model, and the effects of aero-elastic parameters on the wind-induced response and equivalent static wind load were calculated and analyzed. The results show that on the return periods of 100 years, the aerodynamic damping is positive and aerodynamic stiffness is negative. Aerodynamic stiffness is much smaller than the structural stiffness, so has little effect on the natural frequency of the structure. After considering the effects of aero-elastic parameters, the maximum displacement response of the top decreases by 5%, the maximum acceleration response decreases by 10%, and base shear and base moment calculated by equivalent wind loads reduce by about 1.1%. This investigation indicates, bi-axial-forced vibration wind tunnel test is a kind of effective approach for identification of aero-elastic parameters with practical prospects.