杭州国际博览中心单层球面网壳结构稳定性分析

Stability analysis on single layer latticed shell of Hangzhou International Expo Center

杭州国际博览中心城市客厅部分采用了单层球面网壳结构形式.该球壳跨度较大,且由于建筑需要局部开有两个洞口,体型较为复杂.运用MIDAS有限元分析软件,考虑两种荷载工况对该单层球面网壳结构进行了整体稳定性分析.首先对该结构进行了两种工况下的特征值屈曲分析,预测结构的理论屈曲强度;然后根据球壳的屈曲模态,采用一致缺陷法,对结构体系进行了几何非线性屈曲分析,并对比分析了不同的球壳初始缺陷对结构整体稳定性的影响.研究结果表明:该球壳结构对初始缺陷较为敏感,初始缺陷的存在会明显降低结构体系的稳定性,且缺陷越大其稳定临界荷载系数越小;不同的荷载工况,球壳的临界失稳条件也不相同,临界荷载系数差别也较为明显.

Single layer latticed shell has been applied in the Urban Living Room of Hangzhou International Expo Center.There are two hole in the large span shell because of architectural demand,therefore the structure type is more complex.Considering two load cases,global stability analysis of the single layer latticed shell was carried out by finite element analysis software MIDAS.Firstly,linear buckling analysis is conducted with two load cases.The results will be used to predict the theoretical buckling strength of the structure.Then,the geometric nonlinear buckling analysis is conducted with consistent imperfection mode method according to buckling mode of the shell,and the influence of initial imperfection on structural stability under the two load cases was analyzed.The analysis results show that the latticed shell structure was sensitive to initial imperfection which would lower structural stability of the system,and the greater imperfections are,the smaller stability critical load factor will be.Under different load cases,the critical instability conditions are different,and the differences of critical load factor are obvious.