考虑车桥耦合及环境腐蚀的铁路钢桥疲劳分析  

Fatigue analysis of railroad steel bridge considering train-bridge coupling vibration and environmental corrosion

作　　者：胡春建 孙洪斌 卢大治 冯乾朔 余玉洁 朱志辉[1] 王海波 HU Chunjian;SUN Hongbin;LU Dazhi;FENG Qianshuo;YU Yujie;ZHU Zhihui;WANG Haibo(School of Civil Engineering,Central South University,Changsha 410075,China;Shandong Weilai High Speed Railway Company Limited,Jinan 250014,China;Hunan Tieyuan Civil Engineering Testing Company Limited,Changsha 410075,China)

机构地区：[1]中南大学土木工程学院,湖南长沙410075 [2]山东潍莱高速铁路有限公司,山东济南250014 [3]湖南铁院土木工程检测有限公司,湖南长沙410075

出　　处：《铁道科学与工程学报》2024年第3期1256-1265,共10页Journal of Railway Science and Engineering

基　　金：国家重点研发计划项目(2022YFB2603301);山东省交通运输行业重点科研项目(2021-MS4-097);山东省交通运输厅科技计划(2021B103);湖南铁院土木工程检测有限公司开放基金资助项目(HNTY2022K01)。

摘　　要：耐候钢通过改变合金元素以在其表面形成致密保护性防锈层因而具备良好的耐大气腐蚀性能,因此其在免涂装使用中为带锈工作,应用于公路和铁路桥梁中时可能存在腐蚀和疲劳耦合损伤问题。基于潍莱铁路线一座全焊接免涂装耐候钢桥开展列车动力作用下的关键构件和焊接节点疲劳损伤分析,并进行考虑腐蚀劣化影响下的疲劳寿命评估。基于列车-轨道-桥梁耦合系统模型研究在高速列车动力荷载下桥梁主桁关键构件动力响应并得到结构中最不利构件位置,分析关键构件在列车通行振动效应下的疲劳损伤度;结合考虑局部节点板精细化的多尺度耦合有限元模型,考虑轨道不平顺和列车运行速度的影响,得到桥梁节点板在不同速度下的疲劳损伤度;考虑环境腐蚀对桥梁疲劳寿命的影响,结合桥梁列车年运营量进行腐蚀环境下桥梁关键杆件和节点的疲劳使用寿命评估。研究结果表明:铁路钢桁梁桥在列车动力作用下不同构件的疲劳损伤不同,刚度较小以及应力响应影响线较短的构件疲劳损伤度更大,其中疲劳损伤度由大到小依次为节点横梁、腹杆、下弦杆、上弦杆。轨道不平顺和列车运行速度对桥梁节点板应力响应最大值影响并不显著,列车运行速度为120 km/h时与所分析桥梁共振更明显。环境腐蚀会降低铁路桥梁疲劳寿命,且对桥梁不同构件寿命影响程度不同。研究成果可为同类型铁路钢桁梁桥在腐蚀环境下的疲劳寿命评估和设计提供参考。The weathering steel has a good atmospheric corrosion resistance due to dense protective surface rust layers,which are produced through changing the alloy elements.Therefore,the weathering steel can be used without coatings,and there may be corrosion and fatigue coupling damage problems when the weathering steel is applied to highway and railway bridges.Based on a fully welded and non-coated weathering steel bridge of the Weilai railway,the fatigue damage analysis of key components and welded joints under train dynamic actions were carried out.The fatigue life assessment considering the influence of corrosion degradation was performed.The train-track-bridge coupling system model was established.The dynamic responses of key bridge truss components under high-speed train dynamic loads were obtained.The fatigue damage degree under the train passing vibration effect was analyzed.To further evaluate the fatigue damage conditions of welded joints,the multi-scale coupled finite element model that contains a refined joint model was established.The fatigue damage degree of the welded bridge joint under different train speeds and track irregularities were analyzed.The influence of environmental corrosion was then involved into the fatigue damage evaluation.The fatigue service life of critical bridge members and joints under corrosive environments and the train running vibration conditions were discussed and compared.Results are drawn as follows.The fatigue damages of different railway bridge truss members are different.The bridge members with the lower rigidity and shorter load paths have greater fatigue damage degrees.The fatigue damage degree located decreasingly at joint cross beam,web chord,bottom truss chord,and upper truss chord.The track irregularity and train running speed have significant influence on the dynamic stress responses at the welded joint.The 120 km/h train running case has the maximum resonance responses.The environmental corrosion can reduce the fatigue life of railway bridges,and the fatigue damage d

关 键 词：铁路钢桁梁桥 车桥耦合系统 多尺度有限元模型 应力响应 疲劳损伤分析 腐蚀疲劳寿命评估 

分 类 号：U24[交通运输工程—道路与铁道工程] U441.4[建筑科学—桥梁与隧道工程]