以疲劳评估为目标的大跨钢箱梁桥车桥耦合动力分析方法  

Vehicle-bridge coupling dynamic analysis method for the fatigue assessment ofa long-span steel box-girder bridge

作　　者：范晨[1] 王莹[1] 李兆霞[1] FAN Chen;WANG Ying;LI Zhaoxia(Jiangsu Key Laboratory of Engineering Mechanics,Southeast University,Nanjing 210096,China)

机构地区：[1]东南大学江苏省工程力学分析重点实验室,南京210096

出　　处：《振动与冲击》2020年第6期236-242,共7页Journal of Vibration and Shock

基　　金：国家自然科学基金(51678135,51478108);江苏省自然科学基金面上项目(BK20171350);中央高校基本科研业务费专项资金资助项目(2242016R30009)。

摘　　要：以润扬长江公路大桥北汊斜拉桥为工程背景,基于有限元软件ANSYS和数值计算软件MATLAB研究了以疲劳评估为目标的大跨钢箱梁桥车桥耦合动力分析方法中的一系列技术问题,包括以疲劳分析为目标的车桥耦合振动模型的建模方法和动应力分析方法、基于车桥耦合动应力的桥梁疲劳状态评估方法、不同桥梁应力分析方法的比较,以及路面不平度对桥梁疲劳状态的影响。研究结果表明,以疲劳评估为目标的桥梁车桥耦合动力分析方法能够有效地应用于大跨钢箱梁桥的疲劳状态评估,满足结构局部疲劳损伤累积仿真计算的需要。通过分别对不同应力计算方法下以及不同路面不平度下的桥梁动应力响应的对比分析,表明车辆载荷对桥梁作用的影响是局部的,对局部的桥梁疲劳累积有显著影响,在桥梁疲劳状态评估中采用车桥耦合动力分析方法能得到更为准确的结果。Taking the cable-stayed bridge of Runyang Yangtze River Highway Bridge at the north branch as an engineering background,based on the finite element software ANSYS and the numerical calculation software MATLAB,a series of technical problems in the vehicle-bridge coupling dynamic analysis of long-span steel box-girder bridges were discussed,which include the vehicle-bridge coupling vibration modeling method and dynamic stress analysis method aiming at fatigue analysis,the fatigue evaluation method based on vehicle-bridge coupling dynamic stress,the comparison of different bridge stress analysis methods,and the influence of road roughness on the fatigue condition of the bridge.The results show that the coupled dynamic analysis method can be effectively applied to the fatigue state assessment of long-span steel box-girder bridges,and can meet the need of local fatigue damage cumulative simulation.By comparing the dynamic stresses by using different calculation methods and different road roughness,it is shown that the effect of vehicle load on bridge is local but has a significant effect on the local fatigue accumulation.More accurate results can be obtained by the use of vehicle-bridge coupling dynamic analysis in bridge fatigue condition evaluation.

关 键 词：大跨桥梁 疲劳评估 车桥耦合 路面不平度 

分 类 号：U448.14[建筑科学—桥梁与隧道工程]