悬挑式张弦梁结构的风振分析及抗风设计

WIND-INDUCED VIBRATION ANALYSIS AND WIND-RESISTANT DESIGN OF A CANTILEVERED STRING STRUCTURE

以浦江某体育场悬挑式张弦梁结构为研究对象,探讨了基于风洞试验数据的结构风振响应及等效静力风荷载。建立了考虑拉索几何非线性的有限元模型,采用插值方法将试验测点的风速时程按控制面积等效为有限元节点的荷载时程,并进行结构的风振响应提取。分析表明:若实际工程中采用荷载时程与其他效应组合进行设计,其过程将过于繁琐;采用荷载风振系数建立结构动态响应与等效静力风荷载间的联系,是可靠有效的设计方式。同时基于等效静力风荷载,对罩棚结构进行了几何非线性分析,表明:罩棚不同位置的风振系数存在明显的差异,在进行结构设计时宜采取0°~180°风向角下多分区的风振系数,确保安全性和经济性。

Taking the cantilevered string structure of a stadium in Pujiang as a research object, the wind vibration response and equivalent static wind load of the structure based on wind tunnel test data were discussed. A finite element model considering the cable′s geometric non-linear characteristics was established, and the wind speed time-history of the test points was equivalent to the load time-history of the finite element node by interpolation method, and the wind vibration response extraction was performed. The conclusions are as follows: the combination of wind load time-history and other loads would make the structural design process complicated, and then the load wind vibration coefficient was introduced to establish the relationship between the dynamic response of the structure and the static wind pressure, and it was converted into an equivalent static wind load. Meanwhile, based on the equivalent static wind load, a geometric nonlinear analysis of the cantilevered string structure was carried out. There were obvious differences in wind vibration coefficients at different locations of the canopy, and it was advisable to adopt a multi-partition wind vibration coefficient under 0°~180° wind angle when carrying out structural design to ensure safety and economy.