超高层建筑多种风洞试验方式对比研究

Comparative study of various wind tunnel experimental methods for super high-rise building

为了研究超高层建筑不同风洞试验方式结果的差异及原因,对某347m超高层建筑进行了刚性测压模型、强迫振动模型和多自由度气弹模型风洞试验,并将三种试验结果进行分析。对比了刚性测压模型与气弹模型的风致位移响应,分析气动阻尼比对位移响应的影响;同时对比了强迫振动模型与多自由度气弹模型在湍流场及均匀流场中气弹参数的差异。结果表明：刚性测压模型风洞试验在气弹效应不显著的情况下较为可靠而方便;当气弹效应较显著时,多自由度气弹模型的风洞试验结果更为真实;在均匀流场中,结构发生共振时,强迫振动模型的风洞试验结果有一定的参考价值,但在湍流场中,特别是不发生共振时,试验结果与实际情况存在较大差异。高层建筑强迫振动模型振动形式的不精确性会导致试验结果的失真,将强迫振动模型应用到实际高层建筑抗风时,其振动形式还有待改进。

In order to investigate the difference and cause of results obtained from different wind tunnel experiment methods for super high-rise building,adopting the rigid pressure model,forced vibration model and multi-degree of freedom aeroelastic model,wind tunnel experiment was carried out,respectively,for a 347-m high-rise building.Results obtained from every model were analyzed.The wind-induced displacement response of rigid pressure measurement model and aeroelastic model was compared,and the influence of aerodynamic damping ratio on displacement response was analyzed.At the same time,the difference of aeroelastic parameters between forced vibration model and the multidegree of freedom aeroelastic model in turbulent flow field and uniform flow field was compared,respectively.Results show that the wind tunnel experiment by using rigid pressure model is more reliable and convenient,under the condition that the aeroelastic effect is not significant;when the aeroelastic effect is more significant,the results obtained from wind tunnel experiment by multidegree of freedom aeroelastic model are more true.In uniform flow field,when the structure is resonant,the results from wind tunnel experiment using forced vibration model have some reference value;but in the turbulent flow,especially when there is no resonance,its experimental results are quite different from the actual situation.The inaccuracy form forced vibration model for high-rise building will lead to distortion of the experimental results.When forced vibration model is applied to the actual high-rise buildings,the vibration form needs to be improved.