(上海现代建筑设计(集团)有限公司，上海 200041)

［摘要］索膜结构频率密集、非线性现象严重，其等效风荷载的取值成为结构抗风设计的关键。采用计算流体动力学中的非稳态计算方法，对世博轴索膜结构表面风荷载进行了数值风洞计算；继而将计算得到的风荷载时程直接加载到有限元模型上，进行结构的动力时程分析。数值风洞计算结果表明：非稳态计算不但可以直接获得结构表面的风荷载时程，而且可以准确捕捉到跨临界状态下的漩涡脱落。结构动力时程分析结果表明：索膜结构的风振响应中以背景响应为主，共振响应可忽略不计。采用最大风荷载法得到的计算结果与时程计算结果吻合较好。

［关键词］索膜结构；数值风洞；抗风设计；等效风荷载

Study on equivalent wind load for cable-membrane structure in wind-resistant design of EXPO Axis

Wang Dasui, Lu Dan, Li Chengming, Tian Wei(Shanghai Xian Dai Architectural Design (Group) Co., Ltd., Shanghai 200041, China)

Abstract:Some of the disadvantages, such as closely spaced frequencies and highly nonlinear nature, make cable-membrane structure sensitive to wind load. Using the unsteady calculation, the surface wind pressure on cable-membrane structure of EXPO Axis was simulated by means of the numerical wind tunnel method. Directly using pressure data of the numerical wind tunnel test, the free vibration of a practical cable-membrane structure was analyzed by using the finite element program, and the wind-induced vibration response of the structure was theoretically analyzed. The result shows that use of unsteady simulation not only can obtain wind load time history on structure directly, but also can catch vortex shedding correctly. The nonlinear dynamic time-history analysis shows that, the background response takes the significant part of the total dynamic response, and the resonant response can be neglected. The results by using the instantaneous effect maximum wind method agree well with the time history analysis ones.

Keywords:cable-membrane structure; numerical wind tunnel; wind-resistant design; equivalent wind load

*上海市科学技术委员会科研计划项目世博科技项目(08dz0580305)；国家科技支撑计划项目世博科技项目(2009BAK43B06)。

作者简介：汪大绥，总工，中国工程勘察设计大师。

参考文献

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