RESEARCH ON IMPERFECTION SENSITIVE REGION OF SINGLE-LAYER LATTICED DOMES

The concept of the imperfection sensitive region is given. The advanced stochastic imperfection method is used to research the imperfection sensitive region of single-layer latticed domes. Taking a K6 single-layer latticed dome with a diameter of 50 m as an example, its imperfection sensitive region is made up of the first 12 kinds of joints. The influence of the imperfections of support joints on the stability of the K6 single-layer latticed dome is negligible. Influences of the joint imperfections of the main rib and the secondary rib on the structural stability are similar. The initial deviations of these joints all greatly lower the critical load of the dome. Results show that the method can analyze the structural imperfection sensitive region quantitatively and accurately.

装配式空心毂节点铝合金球面网壳表面风压分布特征及风振响应分析

铝合金网壳具有自重轻、耐腐蚀性好等优点,可以很好地满足复杂建筑造型的要求,近年来在各类大型公共建筑当中得到大量应用.针对装配式空心毂节点铝合金单层球面网壳,采用CFD数值模拟方法,考虑双向流固耦合作用,研究了不同矢跨比、跨度和风攻角条件下,节点刚度变化对网壳表面风压分布特征和风振响应的影响.研究结果表明:当跨度、矢跨比和风攻角不变时,铝合金球面网壳表面风压分布特征不会随节点刚度发生变化,但最大风压系数绝对值将显著增大.网壳节点刚度减小时,节点风振系数和网壳平均位移风振系数增大.当节点考虑为半刚接时,节点刚度每减小50%,网壳节点位移响应均值、均方差及位移波动幅值将增大50~100%,网壳最大位移增大25~70%.铝合金球面网壳矢跨比越小、跨度越小,节点刚度对网壳表面风压系数和节点位移响应的影响越显著.

上海天文馆倒转穹顶铝合金网壳结构设计

上海天文馆结构形态复杂,结构材料种类多,由多种结构体系组成。其中倒转穹顶为一＂碗形＂铝合金单层网壳结构,下部支承于钢筋混凝土环梁上。由于混凝土环梁跨度大,其变形对铝合金结构影响较大,结构设计时,采取整体建模的方式,并考虑支座变形对铝合金结构的影响。对于结构开大洞处,采用钢构件来替换铝合金构件进行加强。计算结果表明,结构性能可靠,满足大震不屈服要求。