在役T构桥梁的有限元模型修正

有限元模型修正是建立精确的基准有限元模型的基础。以在役T构桥梁——324国道乌龙江大桥为工程背景,利用ANSYS软件建立了全桥结构的三维有限元模型,进行了结构静、动力数值模拟分析,并与实测结果进行了比较;结果表明,未修正的有限元模型计算结果与实测结果存在较大误差。通过参数灵敏度分析,确定了对桥梁结构静、动力特性影响均较大的参数;采用零阶和一阶算法,基于自振频率与静力挠度组合的目标函数,对乌龙江大桥有限元模型进行了修正。修正后的有限元模型能较真实地反映结构的实际状态,可作为该桥梁长期健康监测与状态评估的基准有限元模型。

Finite Element Model Updating of an In - service T - Frame Bridge

Finite Element （FE） Model Updating is the basis for establishing a precise FE benchmark model. Based on Wulong River Bridge in 324 state road, a three dimensional FE model of a T - Frame Bridge in service was constructed and both static and dynamic analysis were performed by ANSYS software. Comparison between the calculating results and the testing results in field shows that significant errors exist before updating of the FE model. The sensitive parameters which have greater effect on both static and dynamic characteristics of the bridge were identified from sensitivity analysis of parameter. A refined FE model of the bridge was obtained by updating the initial FE model using the Zero - order Method and First - order Method of ANSYS software, based on an objective function contains natural vibration frequencies and static deformations. The updated FE model can reflect the actual state of the bridge more realistically, and can be used as a reliable benchmark model for long - term health monitoring and condition assessment of the bridge.