摘要
以主跨 1385米的江阴长江公路大桥为背景 ,研究利用环境振动测量值进行悬索桥结构有限元模型修正的可行性。采用的模型修正方法以结构特征值灵敏度分析为基础 ,通过迭代求解二次规划问题修正有限元模型参数。根据江阴长江公路大桥的设计图纸建立悬索桥三维有限元模型并进行固有振动分析。同时利用大桥现场环境振动测量值得到一组结构实测模态参数 ,用以作为有限元模型修正的基准。根据结构特征值灵敏度分析结构选择了一组待修正结构参数并予以修正。修正后有限元模型的动力特性更加趋近于环境振动实测值。最后指出了模型修正不能完全消去大桥结构理论
This paper presents the implementation of the finite element (FE) model updating for a newly constructed long span supension bridge using ambient vibration measurements. A 3 dimensional FE model is first established for the bridge based on design drawings and the dynamic characteristics are then analyzed. Ambient vibration measuring is also conducted to obtain the dynamic characteristics of the bridge which are used to update the FE model modification. The updating method used is an eigenvalue sensitivity based approach with parametric constraints. Based on an eigenvalue sensitivity study, a set of structural parameters is selected for adjustment. Then the FE model is updated in an iterative fashion so as the differences between the analyzed and the measured natural frequencies are reduced. The final updated FE model for the suspension bridge is able to produce natural frequencies closer to the measured ones. Complete elimination of the frequency differences however seems not likely and the cause is briefly discussed.
出处
《振动工程学报》
EI
CSCD
北大核心
2002年第1期74-78,共5页
Journal of Vibration Engineering
基金
国家自然科学基金 (编号 :5 98780 37)
上海市教育基金曙光计划 (编号 :2 0 0 0 sg10 )
