单索面曲梁悬索人行桥主缆线形分析

Cable shape analysis of curved suspension footbridge with single cable plane

提出一种非线性有限元与数值计算结合的迭代法,并拓展大型软件迈达斯悬索桥分析功能,实现单索面曲梁悬索桥空间主缆的迭代找形计算。该方法以刚性支承连续曲梁竖向支座反力控制主缆立面垂度为主,以吊索倾斜角度计算吊索横向力和轴向力控制主缆横向垂度为辅,通过迭代吊索力大小和角度实现主缆找形,最终建立单索面曲梁悬索桥成桥状态三维空间有限元模型。计算结果表明:成桥状态主缆线形顺滑,塔、主缆、吊索和主梁空间布置姿态合理,吊索内力分布均匀合理,从而验证了迭代方法的正确性,为这一复杂桥型的设计分析提供参考。

A non-linear finite element iteration method combined with numerical calculation was proposed and thesuspension bridge analysis function of Midas/Civil software was extended to fulfill the main cable shape-findinganalysis. The rigid roller reactions in a curved beam bridges were obtained and used as reference values of thevertical component of the tension force of the hanger to control the sag in the vertical plane. And simultaneously,the lateral force was determined by adjusting trigonometric angular relation between the hangers and main cablein each iteration to control the horizontal sag of main cable. The iteration was not stopped until the convergencewas obtained. The three dimensional space finite element model of the single cable plane curved suspensionbridge was finally established. The calculation results show that the main cable shape is smooth. The tower, maincable and hanger are rationally arranged and the internal force of the hanger is evenly distributed. All of theseresults verify the correctness of the iterative method and provide a reference for the design and analysis of thesecomplicated bridges.