某工程大型钢拱结构稳定性分析

Stability Analysis of a Large Steel Arch Structure

分析对象包括单拱 ,不同单元的拱系子结构和整体拱结构体系 ,并分有柱间支撑和无柱间支撑两种情况。分析内容有线性稳定 ,完善结构非线性稳定 ,有初始缺陷结构非线性稳定和几何非线性弹塑性稳定分析。分析比较得到如下结论 :几何非线性和初始缺陷对深拱结构体系在拱平面内的整体稳定性的影响不明显 ,而材料的塑性性能影响十分明显 ;拱系结构的稳定性分析用单拱或少量单元的拱系子结构代替并不一定偏于安全。

Stability analysis of a single arch,a sub-structure composed of a series of space arches and beams and the whole arch-structure is presented in the paper. Two different structural systems with and without braces in the sub-structure and the whole structure are considered. The linear and nonlinear stability analysis of the perfect and the imperfect arch-structures are conducted. The elasto-plastic stability analysis of the perfect and the imperfect arch-structures are also carried out in the paper. The numerical results show that the effects of geometric nonlinearity and imperfections on the structural stability are not so obvious,but the effect of the plasticity is obvious. It is not safe to justify the stability of whole arch-structure by means of the stability of the single arch or the sub-arch-structure.