大开孔单层椭球网壳-组合楼板混合结构设计及稳定性分析

本文以九寨沟甘海子国际会展中心展厅结构为工程背景,介绍了单层椭球网壳-组合楼板混合结构的分析设计过程。首先,采用相贯节点的计算理论,对该工程采用的鼓节点的设计进行了详细论述。此外,本文采用子空间迭代法对该混合结构进行了特征值屈曲分析;采用非线性有限元理论,结合N-R法和柱面弧长跟踪技术,对该结构进行了考虑初始缺陷的非线性全过程分析;并采用估算公式进行了校核。计算结果表明,特征值屈曲分析结果是局部失稳的极限荷载,而非线性屈曲分析结果是整体失稳的极限荷载。对于有局部刚度薄弱的结构,采用非线性屈曲分析得到的极限荷载更为合理。

Design and stability analysis of single layer elliptical shell-composite deck slab hybrid structure with large holes

The exhibition hall of Jiuzhaigou Ganhaizi International Meeting Center is a hybrid structure composed of single layer elliptical shell and composite deck slabs. There is a single layer elliptical shell outside the hall and the composite deck slabs are supported on the joints of the shell inside it. Single layer elliptical shell composite deck slabs hybrid structure is a complicated space structure. In this paper the design and stability analysis of this hybrid structure with large holes as a practical project is introduced. By using the concerned theory of the intersecting joint, the design of the drum joint is described in detail. Critical load was obtained by three methods. The eigen buckling was analyzed using the subspace iteration method. By the geometrical nonlinear finite element method, the equilibrium path was traced with regard to the initial geometric imperfection using the cylindrical arc length technology and N R method. Critical load was estimated by the fitting formula. The result obtained by eigen buckling analysis is the critical load corresponding to the local instability. And the result obtained by the geometrical nonlinear finite element method is the critical load corresponding to the global instability. The results showed that critical load obtained by the geometrical nonlinear finite element method is more rational, especially for the structures with weak local rigidity.