大跨度索穹顶结构风振响应的频域分析

建立了考虑和不考虑上覆膜影响的两个有限元分析模型,针对一工程实例,进行了结构的模态分析以及风振响应的频域分析,得到了结构的脉动风振位移响应根方差.结果表明:参振模态的适宜取值随跨度的增大而增大;对于跨度100m以上的类似索穹顶结构,建议所选的参振模态数不小于450;CSM体系索、立杆节点的动位移根方差小于CS体系;CSM体系中膜面的耗能作用不可忽略;在风荷载作用下,CSM体系的脉动风能大部分由膜面耗散;对于跨度较大的索穹顶结构,顶部索膜结构对整体结构的风振响应有明显的影响.

Frequency Domain Analysis for Wind-Induced Vibration Response of Long-Span Cable Dome Structures

In this paper,two finite element models are established to respectively analyze the wind-induced vibration response of cable dome structures with and without top cable-membrane.Then,the structural mode and the wind-induced vibration response in the frequency domain are analyzed through an engineering example,and the standard deviation of the displacement responses to the fluctuation wind load is obtained.The results show that(1) the suitable number of dominant modes increases with the enlargement of the span;(2) for the cable-dome-like structures with a span longer than 100 m,the number of dominant modes is suggested to be more than 450;(3) the standard deviations of the node displacements of both the cables and the poling in CSM are less than those in CS;(4) the envload affection of the membrane can not be ignored in CSM;(5) in CSM,the structural pulse wind energy is mostly dissipated by the membrane;and(6) top cable-membrane greatly affects the wind-induced vibration response of long-span cable dome structures.