斜拉桥扁平钢箱梁的有限混合单元法分析

Analysis of Flat Steel-Box-Girder of Cable-Stayed Bridge by Finite Mixed Element Method

同时利用六自由度的梁单元和壳单元模拟桥梁中不同位置扁平钢箱梁,根据平截面假定推导了两种单元在交界面上的约束方程,形成混合单元法.通过算例验证了该方法的正确性,它不仅能够计算构件的应力,还可以计算其整体稳定、局部稳定以及局部稳定与整体稳定的相关作用.利用该方法对苏通大桥进行整体受力计算,得到钢箱梁板件的横桥向和顺桥向应力,分析了钢箱梁顶板应力在横桥向的不均匀性.

A finite element method was proposed to analyze the mechanics behavior of flat steel-box-girder of cable-stayed bridge.In the method both beam element with six free degrees and shell element were employed to simulate different parts of girder simultaneously.The method can calculate not only the member stresses but also the whole stability,local stability,and their interaction,and the analysis example shows its result is satisfying.Mechanics behaviors of Sutong bridge were computed by this method,and longitudinal stress,transversal stress of plates of the girder and section stress distribution were discussed consequently.