基于环境激励的桥梁结构动力测试及模型修正

桥梁结构的动力特性是结构动力计算和抗震分析的基础,也是桥梁健康状况监测的一个重要指标.首先根据设计图纸建立了312国道上的一座公跨铁立交桥的三维有限元模型,分析了桥梁的动力特性,同时通过环境振动测试获得了桥梁的实测动力特性,然后在灵敏度分析和优化理论的基础上,选取了一组设计参数,对桥梁的有限元模型进行了修正.修正结果表明该方法简单有效,修正后的有限元模型能够较好地反映桥梁的动力特性,可用于检测桥梁在复杂外力作用下的动力响应,能更好地为后期的损伤识别和健康评估服务.

Dynamic Test and Finite Element Model Updating of Bridge Structures Based on Ambient Vibration

The dynamic characteristics of bridge structures are the basis of structural dynamic computation and seismic analysis,and are also an important target of health condition monitoring.In this paper,a three-dimensional finite-element model was first established for a highway bridge over a railroad on NO.312 National Highway based on design drawings,the dynamic characteristics of the bridge were studied using finite element analysis and ambient vibration measurements.Thus,a set of data was selected based on sensitivity analysis and optimization theory,and the finite element model of the bridge was updated.The results of updating show that this updating method is more simple and effective,the updated finite element model can reflect the dynamic characteristics of the bridge better,it can be used to predict the dynamic response under complex external force and helpful for further damage identification and health condition monitoring.