突然开孔对平屋盖结构静动力风荷载的影响

Influence of Sudden Opening on Static and Dynamic Wind Load for Flat Roof Structures

采用刚性模型和气动弹性模型风洞试验,研究迎风面突然开孔对平屋盖结构静动力风荷载的影响.根据试验结果,分析了开孔前后平屋盖结构的平均风压系数、均方根风压系数和风振响应的变化规律,提出了开孔结构平屋盖净风压的计算方法,以及平屋盖风振系数的简化处理方法.研究表明:迎风面突然开孔会大幅增大平屋盖结构的静动力风荷载,在结构设计中必须考虑内外压的联合作用及相应的风致动力效应,但静动力风荷载的比值变化不大,因此仍可沿用封闭结构的风振系数.

Wind tunnel tests of rigid and aeroelasdc model were carried out to investigate the influence of windward sudden opening on static and dynamic wind load for flat roof structures. Based on the experimental results, mean and RMS wind pressure coefficients and wind-induced response for flat roof structures before and after sudden opening were analyzed. A simplified method for＇determining the net wind pressure and wind load on flat roof sm^cmres was prol^ed. Study result shows that the static and dynamic wind load of flat roof structures may increase greatly when a windward opening is created suddenly and that it is necessary to consider the interaction between and joined effect of the internal-external pressure and corresponding dynamic ef{ect in engineering. However, the ratio of dynamic wind load to static wind load does not change remarkably. Thus the windload factor for flat roof structures of sealed building is still applicable.