屋盖倾角对悬挑曲面屋盖风压特性的影响  

Effect of pitch angles on wind pressures of cantilevered curved roofs

作　　者：刘慕广[1] 谢壮宁[1] 余先锋[1] 石碧青[1] 

机构地区：[1]华南理工大学亚热带建筑科学国家重点实验室

出　　处：《建筑结构学报》2018年第1期21-27,共7页Journal of Building Structures

基　　金：国家自然科学基金项目(51208213,51778243);中央高校基本科研业务费专项(2015ZZ018)

摘　　要：以体育馆的悬挑曲面屋盖为研究对象,基于风洞试验测试了三种不同倾角屋盖的风压特性,对比分析了屋盖倾角对风压分布及平均、极小风压系数的影响。结果表明：屋盖倾角变化对其平均和极小风压系数的影响显著,尤其是受锥形涡或分离、再附流影响的屋盖局部区域,但风压变化规律受测点的相对位置、屋盖跨度、初始倾角等影响;三种不同倾角屋盖的最不利风压系数极值均位于屋盖角区前端,屋盖倾角渐次增大后的模型M2、M3,其最不利平均风压系数极值较模型M1分别增大7.1%、13.8%,最不利负风压系数极值较模型M1分别增大15.0%、11.0%;受锥形涡分离再附主导影响的屋盖角区,随屋盖倾角增大,其迎风边缘与再附区的风压系数整体上变化趋势一致,即最不利平均风压系数逐渐增大,最不利负风压系数先增大而后少许减小;受分离流或再附流主导影响的其他屋盖区域,其最不利平均、负风压系数随屋盖倾角变化的规律性较差,需分区单独分析。Taking stadium with cantilevered curved roofs as research object, the wind pressure distribution, mean pressure coefficients and peak negative pressure coefficients of large cantilevered spatial roof with three different roof pitches were investigated by wind tunnel experiments. It is found that roof pitch angle have a significant effect on the mean pressure coefficients and peak negative pressure coefficients, especially the roof area affected by the conical vortex or separation and reattachment. However, the change rule of wind pressure distribution to roof slopes is related to the relative position of taps, roof span and initial pitch angles of roof. It is seen that the extreme value of the most unfavorable wind pressure coefficients for the three models are all located at the front edge of roof comer. For the models of M2 and M3 with gradually enlarging roof slopes compared with the model M1, the extreme value of the most unfavorable mean wind pressure coefficients increase by 7.1% and 13.8% respectively, and the extreme value of the most unfavorable negative wind pressure coefficient increases by 15.0% and 11.0%, respectively. The wind pressure coefficients of roof comer, which is dominantly affected by the separation and reattachment of conical vortex, vary consistently at windward edge and reattachment zone. As roof pitch angle rise, the most unfavorable mean pressure coefficients are gradually increasing, while the most unfavorable negative pressure coefficients decrease after increasing. For other roof regions, where the wind pressure coefficients are mainly influenced by separation or reattachment flow separately, the most unfavorable mean and negative pressure coefficients for different taps emerge large deviations with the increasing of roof pitches. The change rule ought to be discussed

关 键 词：悬挑屋盖 屋盖倾角 风洞试验 平均风压系数 极小风压系数 

分 类 号：TU393.303[建筑科学—结构工程] TU312.1