赛格广场大厦楼顶双桅杆结构的风致高阶涡振分析  

Wind-induced high-order vibration of a twin-mast with large cross-section at top of Saige Plaza Building

作　　者：黄铭枫[1,2] 唐归 陶慕轩[3] 廖孙策 高迈 聂鑫[3] HUANG Mingfeng;TANG Gui;TAO Muxuan;LIAO Sunce;GAO Mai;NIE Xin(Institute of Structural Engineering,College of Civil Engineering&Architecture,Zhejiang University,Hangzhou 310058,China;Center for Balance Architecture,Zhejiang University,Hangzhou 310058,China;Department of Civil Engineering,Tsinghua University,Beijing 100084,China)

机构地区：[1]浙江大学建筑工程学院结构工程研究所,浙江杭州310058 [2]浙江大学平衡建筑研究中心,浙江杭州310058 [3]清华大学土木工程系,北京100084

出　　处：《建筑结构学报》2022年第12期1-10,共10页Journal of Building Structures

基　　金：国家自然科学基金项目(52178512);浙江省自然科学基金委员会重点项目(LZ22E080006)。

摘　　要：赛格广场大厦5·18振动事件表明不能忽略楼顶桅杆高阶涡激振动对主体结构的影响,为此,根据相关设计资料和实测数据,分别建立了赛格广场大厦楼顶双桅杆结构的有限元模型与考虑桅杆动力特性改变的修正模型,利用双桅杆绕流CFD(computational fluid dynamics)数值模拟所得气动力荷载时程,计算分析了双桅杆结构在刚度退化前后的风致振动响应特性。推导得出了悬臂钢管涡激振动幅值估算公式,研究了双桅杆的气动力荷载空间分布模式与荷载激励频率对双桅杆风致振动特性的影响。计算结果表明:赛格广场大厦楼顶桅杆的长期累积损伤导致刚度降低是桅杆发生高阶大幅涡振的原因之一;在频率为2.12 Hz的理想涡激力作用下,考虑刚度退化的桅杆修正模型风致振动响应幅值最大,与涡振幅值理论公式预测值202 mm相近,基本符合赛格大厦顶部桅杆风致振动幅值的实际观测情况,文中工作在一定程度上重现了5·18赛格广场大厦楼顶桅杆结构大幅涡激振动的现象。The 5·18 vibration event of Saige Plaza Building indicates the importance of vortex-induced vibrations(VIV) of large cross-section pipes severing as the mast at the top of Saige Plaza Building. Based on the design documents and field measurements of the mast, two finite element models of the twin-mast were established for design conditions and actual stiffness degradation conditions, respectively. The wind-induced vibrations of these two models were analyzed and compared based on the aerodynamic loads derived from the computational fluid dynamics(CFD) simulation of wind flow around the twin-mast. A semi-analytical formula for predicting the maximum VIV amplitude of a cantilever steel pipe was proposed. The effects of load spatial distribution and load frequency on the vibration response properties of the twin-mast were investigated by applying the ideal VIV aerodynamic forces. The results show that the recent occurrence of high-order mode VIV of the twin-mast is closely related to the stiffness degradation of steel pipes due to the accumulated corrosion damage. The maximum VIV amplitude of 202 mm predicted by the semi-analytical formula agrees well with the result obtained from the finite element model considering stiffness degradation under the ideal vortex-induced force with a frequency of 2.12 Hz. The calculated maximum VIV amplitudes are also comparable to the observation during the 5·18 event. This work serves as a preliminary reproduction of VIV of the actual twin-mast at the top of Saige Plaza Building.

关 键 词：双桅杆结构 涡激振动 有限元分析 高阶振动 计算流体动力学模拟 

分 类 号：TU973.213[建筑科学—结构工程]