双层球面网壳是一种缺陷敏感型结构,影响结构稳定性的初始缺陷主要有杆件的初弯曲、杆件的残余应力和结构节点的初始安装偏差三种.本文首先利用有初始弯曲的杆件的平衡微分方程推导得到了杆单元的和始弯曲影响系数,利用CRC模型考虑了杆件残余应力的影响,并且利用有限元软件ANSYS的UPFs程序接口,开发了可以考虑残余应力和初始弯曲的杆单元;然后对原有仅能考虑节点安装偏差的随机缺陷模态法进行了改进和补充,最后提出了一种能够同时考虑三种缺陷的双层球面网壳的稳定分析方法.该法与一致缺陷模态法相比,具有更高的精度.
The double-layer spherical reticulated shell is sensitive to imperfections. The initial imperfections reducing structural stability include initial curvature, residual stress of bar element and installation deviation of nodes. The influence factor of initial curvature was obtained by deducing the differentiating equilibrium equations and the influence of the residual stress was considered by model CRC. With the UPFs in ANSYS, the programs of bar element were developed to consider the influences of initial curvature and residual stress. The stochastic imperfection method about installation deviation of nodes was advanced, and a new method was put forward for stability of double-layer spherical reticulated shell. Comparing with the consistent imperfect buckling analysis method, the precision of the proposed method is higher.