润扬斜拉桥有限元模拟及模态分析

本文主要研究润扬长江大桥北汊斜拉桥以结构健康监测和状态评估为目标的空间有限元模型建立过程中的一些基础性问题。在建模过程中,尽可能多地考虑了一些影响全桥有限元模型精度的因素:如斜拉索的几何非线性(重力垂度和初始应力),将构造正交各向异性钢箱梁桥面板用复合材料力学的方法等效为物理正交各向异性板等。然后应用所建立的有限元模型进行模态分析,最后将有限元模态计算结果与环境振动试验结果进行比较,验证了润扬斜拉桥有限元模型的有效性。由此建立的有限元模型可以为该桥的结构健康监测和状态评估提供分析的基础。

Finite element modeling and modal analysis of Runyang Cable-stayed Bridge

This paper aims to develop a three-dimensional finite element(FE) model of Runyang Cabled-stayed Bridge for structural health monitoring(SHM) and condition assessment.During the finite element modeling of the bridge,the factors affecting the accuracy of the finite element model are discussed in detail,such as,the geometrical non-linearity of the cable including gravitational sag and initial tension,and the structural orthotropic steel box-girder deck to be equivalent to physical orthotropic deck by using compound material mechanics,and so on.Then modal analysis is carried out by using the developed FE model.The results calculated by FE model are compared with those from field test and suggest that the developed FE model of Runyang Cable-stayed Bridge is valid to some extent and can be used as the basic model of bridge in the analysis of structural health monitoring system.