襄阳汉江三桥成桥状态有限元计算研究

FEM Computation Study of the Design State of Xiangyang Hanjiang the Third Bridge

以襄阳汉江三桥为研究对象,充分考虑大跨度预应力混凝土斜拉桥的结构特点,运用MIDAS/Civil建立其整体有限元模型,讨论了大跨度双索面斜拉桥有限元模型建立过程中存在的一些关键问题如垂度效应、梁柱效应、节点刚性区问题。通过比较这些关键因素对数值计算结果的影响,分析其成桥状态下的结构静动力性能。结果显示,3种效应对于该结构的固有频率及成桥索力影响不大,而对主梁应力的影响较为明显。

The finite element model of the third Xiangyang Hanjiang Bridge, considering the structural features of large-span prestressed concrete cable-stayed bridges, is established by means of MIDAS/ Civil software in this paper. Some key problems including cable sag effect, P-delta effect and joints＂ rigid zones, which would be encountered in modeling large-span cable-stayed bridges, are discussed comprehensively. The effects of those facts on the static and dynamic properties of the bridge are analyzed, and the conclusions obtained could be referred for the FEM computation and analysis of similar bridges. As the results displayed, three factors have small effect on the natural frequency and cable force. However, it have a great impact on the stress.