罗永峰   郑  科   董  洁
    （同济大学建工系  上海 200092）

[提要]  现行网架规程中的焊接空心球承载力设计公式是以试验为基础的经验公式，对以稳定性控制的球壳，难以求得较为精确的屈曲临界点。应用对称旋转薄壳屈曲的非线性有限元理论，对空心球节点进行大位移弹塑性屈曲分析，得出了可供设计参考的空心球承载力数据表，并回归出适用于大直径空心球计算的近似公式，以确定空心球节点的失效状态及临界荷载。
[关键词]  空心球节点  临界荷载  非线性有限元

The design formulae of load-bearing capacity of spherical thin-shell joints in the spatial trusses code are empirical, which are based on limited tests. These formulae are hard to be used to determine the exactly critical loads for compressive shell joints. The nonlinear finite element theory of shells of revolution is applied to analyze the large-deflection and elasto-plastic behavior of the large hollow spherical shell joints.A series of joints that are often used in engineering are calculated and compared. The numerical results are listed in several tables and a new design formula is presented
for future engineering reference.
Keywords: spherical thin-shell joint;  critical load;  nonlinear FEM