三塔结合梁斜拉桥空间有限元模型对比分析

Comparative Analysis of the Spatial FEM Model of Composite Girder Cable-stayed Bridge with Three Towers

斜拉桥复杂的超静定结构形式增加了其结构分析的难度,模型分析结果与实际结构测量结果之间总是存在一定的误差。传统的建模方法是对主塔、斜拉索和主梁进行大量的简化,用梁单元和杆单元来建立平面或空间的杆系模型,误差较大。本文针对武汉二七长江大桥,通过ANSYS有限元软件,采用空间板壳和实体单元与梁单元相结合,建立其精细化空间有限元模型,分析该桥的空间内力分布及变形特征,同时建立其简化单主梁模型进行对比分析,分析结果表明,精细化有限元模型不仅能更为准确的模拟实桥的空间受力状态,给出主梁各处沿横向的位移及内力分布,并且能实现准确的实桥运营阶段结构分析,本文分析结果对该类大跨径桥梁具有一定的借鉴作用。

Because of the complex statically indeterminate structure form of cable-stayed bridge,structural analysis becomes more difficult.There are always some errors between the model analysis results and the real structure measured results.Tra ditional modeling method was to simplify the bridge tower,stay-cable and girde r in large quantity,and establish the planar or spatial frame model with beam a nd bar element.In this paper,a refined FEM spatial model of Wuhan erqi changji ang river bridge was established with space shell,solid and bar element through finite element software of ANSYS.Then the space internal force distribution an d deformation feature of this bridge were analyzed.Moreover,a simplified singl e-girder model was established to make comparative analysis.The results reveal ed that the refined FEM model can not only simulate the space force state of the real bridge more accurately and give the transverse displacement and internal f orce distribution of the beam but also analyze the real structure in the service stage accurately.The analysis results in this paper have some reference functi on for this long-span bridge.