武汉某体育馆大跨度圆钢管拱桁架结构稳定性分析

Stability Analysis of Long-span Arch Truss Structure with Circular Steel Tube

武汉某体育馆屋盖采用圆钢管拱桁架结构,单榀拱桁架的截面形式为倒三角形,两端支承于立体钢桁架上,该结构的整体稳定性是设计的重点。考虑完善及带缺陷结构两种情况,对单榀及多榀拱桁架子结构进行线性屈曲、几何非线性稳定及弹塑性非线性稳定分析,得到了临界荷载与位移的关系曲线。分析结果表明,初始缺陷及几何非线性对该结构的稳定承载力影响不明显,而材料非线性的影响显著,加强平面外支撑对于提高结构的整体稳定性具有重要作用。

The overall structural stability of delta-sectional arch truss is the key point of design for a gymnasium in Wuhan City, which is composed of six pieces of delta-sectional arch trusses and supported by two spatial steel trusses. Linear buckling, geometric nonlinear stability and elastic-plastic nonlinear stability were investigated, allowing for the perfect and imperfect structures. The relational curves of critical load-displacement were obtained. The analysis results demonstrate that initial imperfection and geometric nonlinearity of the trusses have little influence on the stability load-bearing behavior, but the elastic-plastic material performance makes the stability capacity reduce significantly. Strengthening of the out-of-plane bracing for the trusses is important for the overall stability of the arch truss structure.