双曲拱桥有限元分析中建模方法研究

Study on Finite Element Modeling for Double Arch Bridges

结合南京长江大桥引桥中双曲拱桥的承载能力检算,提出按刚度等效原则把拱肋与拱波简化为梁格体系的计算模型,采用空间梁单元模拟拱肋与拱波,缩减了双曲拱桥全桥建模和结果分析时的计算工作量。对此计算模型,采用ANSYS软件,选取了桥梁荷载中的几种典型工况做模拟计算,与ANSYS有限元软件建立的另一精细模型的计算结果及相同加载方式下的现场试验实测数值进行了对比,并对三组数据结果做了简要的分析。

In assessment of the load bearing capacity for the existing Yangzhi River bridge,in terms of the equivalent stiffness princi- ple,a new simplified computational modeling for the arch rib and two way curved arch tile system is proposed,in which,both the arch rib and two way curved arch tile are modeled using special beam element based on an equivalent stiffness approach,so that the computational work decreases substantially.Analyse of the bridge model is carried out using the ANSYS software in several typical load conditions of the bridge.The results are compared with those derived from the fine finite element model in which the arch rib and two way curved arch tile of the structure are modeled by shell element,and the on-site bridge testing data.The rationality of the equivalent finite element model has been discussed and summarized.