论文部分内容阅读
基于缩尺比模型的风洞试验不易直接测试细小构件上的风荷载,借助数值风洞技术,通过建立建筑及其屋面檩条的空间模型,精细划分局部网格,获得不同风向角下屋顶敞开式檩条构件的风荷载分布.结果表明,敞开式屋面檩条构件受斜风作用更为不利,同时水平向的切向力比垂直向吸力更为显著,是构件抗风计算中不可忽略的重要部分.屋顶檩条风荷载分布具有明显的规律性,在屋面的尖角区域最大,因为该区域屋面曲线弧度最大,气流在该位置产生了较强分离对流,从而形成了较强的垂直向风吸力和水平切向力;在屋面的外侧区域风荷载也较大,与建筑边缘区的气流分离直接相关;在屋面的内侧区域明显较小且分布较为均匀.通过增加将檩条底部封闭的气动措施可以有效地减小屋面外侧区域檩条极值风荷载20%以上,但对屋面内侧区域的檩条效果不明显,建议将初始檩条底部敞开设计方案优化为在建筑边缘区域檩条底部封闭.
The wind tunnel test based on the scale-scale model is not easy to directly test the wind load on the small components. With the help of numerical wind tunnel technology, through the establishment of the spatial model of the building and its roof purlins, the local grids are subdivided and the roof open The results show that the open roof slats are more adversely affected by the oblique wind and the horizontal tangential force is more significant than the vertical suction, which is an important part which can not be neglected in the wind resistance calculation of the component. The distribution of wind load on the roof breeze has obvious regularity, which is the largest in the corner area of the roof. Because the curvature of roofing curve is the largest in this area, strong convection convection is generated in this position, resulting in strong vertical wind suction and horizontal Tangential force; the wind load is also larger in the outer area of the roof, which is directly related to the airflow separation in the edge of the building; the inner area of the roof is obviously smaller and more evenly distributed. By increasing the aerodynamic measures of closing the bottom of the sliver, Reduce the outer side of the roof area of the maximum wind load of purlins more than 20%, but the inner side of the roof purlins effect is not obvious, it is recommended that the initial bottom The Ministry’s open plan was optimized to be closed at the bottom of the purlin at the edge of the building.