开孔建筑屋盖风振响应中的气动阻尼识别

建筑物门窗开启后形成开孔房屋,大跨度柔性屋盖结构在内外压共同作用下表现出显著的流固耦合特性,气动阻尼在开孔前后屋盖结构的振动中将发生改变。本文结合风洞模型试验,联合采用经验模态分解法、随机减量法和希耳伯特变换法对一大跨屋盖风致振动的气动阻尼进行识别。运用这一方法分别识别出大跨柔性屋盖在四周封闭和迎风面开孔两种状态下的气动阻尼。在此基础上对本模型屋盖进行的风振响应计算表明,气动阻尼有效地抑制了屋盖风振,考虑气动阻尼影响的数值计算与试验结果吻合得较好,说明本文采用的联合方法能有效地识别柔性屋盖结构风振响应中的气动阻尼。

Identification of aerodynamic damping for roof wind-induced response of opening building

Wind-induced dynamic response of roof structures is characterized by fluid-structure coupling interaction,which includes internal and external pressure after opening.It is evident that aerodynamic damping is changed with the presence of opening.An identification of aerodynamic damping method combined with empirical mode decomposition(EMD),the random decrement technique(RDT) and the Hilbert transform(HT) for long-span roof was presented.Aerodynamic damping in the case of round close situation and opening situation are calculated respectively using this method and compared with the results of wind tunnel tests.The buffeting responses of the wind tunnel model are analyzed in detail to demonstrate the mothed.The study shows that dynamic damping has a significant effect on the restraint of wind-induced vibration.It is also shown that numerical calculation considered with dynamic damping is consistent with experimental observation.