钢管拱桁架的静力稳定性研究

Study on the Static Stability of Steel Pipe Arch Truss

利用大型有限元程序ANSYS对拱桁架进行了静力稳定性分析,同时考虑了初始缺陷、荷载作用范围及约束条件等因素对拱桁架静力稳定性能的影响.结果表明:拱桁架的失稳形态为整体失稳;初始缺陷对拱桁架的稳定承载力和失稳时的变形都影响显著;拱桁架在半跨荷载作用下的稳定临界承载力比满跨时略高,但变形却比满跨时大得多;约束绕x轴的转动和固定约束的作用基本相同,使结构的稳定承载力比只限制位移提高10.6%.

This paper analyzes the static stability of steel pipe arch truss by using large finite element program ANSYS. It also takes into account the influence of some factors on it, such as primitive deficiency, the scope of load action, constraint conditions and so on. The results indicate that its losing stability pattern is unitary losing stability. The primitive deficiency has distinct influences on its bearing capacity and deformation when steel arch truss loses stability, and its critical bearing capacity under half span load action is much higher than that under the whole span while the deformation degree is much larger. Compared with restricting displacement alone, the effect of X-rotation is almost the same as fixed constraint, which makes the structure＇s bearing capacity increases to 10.6%.