敞开型大跨度屋盖结构风振响应的风向效应

Effect of Wind-Induced Response Considering Direction for Long-Span Open-Type Roof Structure

基于刚性模型风洞试验,在不同风向角下对巴哈马国家体育场结构的表面风压进行了测量,根据模型测压结果,对模型的表面风压分布特点与机理进行了分析。在计算出屋盖平均风荷载作用下响应的同时,根据随机振动理论并结合结构的整体有限元模型,编制程序计算了屋盖结构的风振响应。计算与分析表明,对于敞开型大跨度屋盖,在不同的风向条件下由于建筑物的干扰效应不同,引起气流绕屋盖结构所形成的风场有着很大的不同,风向不仅影响结构在平均风荷载作用下的响应,也影响结构在脉动风荷载作用下的风振响应,因此对此类屋盖结构进行抗风验算与评估时应充分考虑风向的影响。

Based on a wind tunnel test,wind pressure distributions on the roof structures of Bahamas national stadium were measured in the wind tunnel with a rigid model.The characteristics and mechanism of wind pressures distributions on the roof structures are analyzed according to the wind tunnel test results.The response induced by the mean wind loads is computed,and on the foundation of the random theory the computation program in conjunction with the finite element model is developed to calculate the wind dynamic response.After the computation and analysis,it is shown that,considering different wind directions,the wind pressure field on the roof caused by wind flow around the roof structure varies apparently by interference effects of the building.As a result,the response induced not only by the mean wind loads but also by the fluctuating wind loads are all changed notably with the wind directions.So it is necessary to consider the wind direction for the open-type roof structure to computer and evaluate the wind-induced response.