空间网壳结构风振系数计算分析

Wind load factor calculation of long-span spatial reticulated shell

以某空间网壳结构为例,采用刚性模型风洞测试风压时程数据,形成有限元模型节点风荷载时程计算风振响应,从而得到风振系数。由于结构外形复杂,计算了3个方向的位移风振系数。分析表明,3个方向上屋盖风振系数随风向角变化规律类似,大拱曲边涡脱效应使得0度、180度风向角为最不利风向角。另外,比较了非线性模态叠加法与Newmark积分计算结果,表明该方法在充分选取参振振型后可快速求得风振系数,精度满足工程要求。

A spatial reticulated shell structure was considered as an example. Wind load factors were calculated by adding time-history load which gained from rigid model wind-tunnel test on FEM. Because of the complicated shape of the shell, displacement wind load factors in three degrees were calculated. The analysis showed that the three degrees wind load factors of the shell had similar rules along with wind direction angles. The effect of vortex-shedding on arch border resulted in 0° and 180°wind direction angle being the most disadvantage conditions. Furthermore ,nolinear mode superpostion method was compared with Newmark integration method in calculating wind load factors. And it has been proven to be efficient and accurate on condition that enough models were selected in nolinear mode superpostion method.