基于强迫振动的高层建筑扭转向气弹效应

Torsional Aero-elastic Effects of High-rise Buildings Based on Forced Vibration

基于可设定振动频率和振幅的扭转强迫振动装置,采用同步测试风洞试验方法,测试了不同试验风速和扭转振幅情况下高层建筑模型表面各测点的风压时程与结构扭转位移时程.推导了结构扭转气弹效应识别方法,并进行不同风速、不同振幅和不同刚度偏心情况下的矩形高层建筑扭转向气弹效应的评估.结果表明:高层建筑扭转向气动刚度可以忽略不计;扭转向气动阻尼对高层建筑响应的影响应予以考虑,尤其是当风速达到临界值时,气动阻尼迅速下降,产生负气动阻尼.

Based on torsional motion-induced device with programmable vibration frequency and amplitude,the time history of wind pressure and displacement for each measurement point on the high-rise building model surface was measured by synchronous multi-pressure sensing system in wind tunnel test.The identification method of structure torsional aero-elastic effect was derived.The torsional aero-elastic effects of rectangular high-rise buildings with different wind speeds,amplitudes and stiffness eccentricities were evaluated.The test results show that the torsional aerodynamic stiffness is negligible,but the torsional aerodynamic damping should be taken into consideration.Especially,when the wind speed reaches the critical wind speed,aerodynamic damping decreases rapidly and comes into negative aerodynamic damping.