基于损伤等效原理的铁路钢桥疲劳损伤系数 计算方法  

Calculation Method of Fatigue Damage Factors of Railway Steel Bridge Based on Damage Equivalence Principle

作　　者：赵会东 阎武通 ZHAO Huidong;YAN Wutong(Appraisal Center for Railway Engineering Design,China State Railway Group Co.,Ltd.,Beijing 100844,China;Railway Engineering Research Institute,China Academy of Railway Sciences Corporation Limited,Beijing 100081,China;State Key Laboratory of High Speed Railway Track System,Beijing 100081,China)

机构地区：[1]中国国家铁路集团有限公司工程设计鉴定中心,北京100844 [2]中国铁道科学研究院集团有限公司铁道建筑研究所,北京100081 [3]高速铁路轨道系统全国重点实验室,北京100081

出　　处：《中国铁道科学》2024年第6期130-139,共10页China Railway Science

基　　金：中国铁道科学研究院集团有限公司院基金课题(2023YJ183);国家重点研发计划项目(2022YFB2602900)。

摘　　要：为研究铁路钢桥疲劳损伤系数的合理取值,以欧洲规范中的疲劳损伤等效原理为基础,建立列车荷载效应历程的等效疲劳应力幅迭代算法,提出基于完全损伤等效的疲劳损伤系数计算方法。以欧洲规范中的12种列车编组类型为例进行方法应用验证,并与现有双斜率换算方法进行对比分析。采用该方法讨论拉-压应力历程、S-N曲线形式对疲劳损伤系数计算的影响。结果表明:采用双斜率换算方法获得的计算结果普遍高于欧洲规范取值,最大偏差为22.5%,而采用疲劳损伤系数计算方法获得的计算结果与欧洲规范取值最大偏差仅为1.1%,验证该方法的合理性,揭示了欧洲规范中疲劳损伤系数的取值依据;不区分拉-压应力历程、统一按照应力幅计算疲劳损伤的方式是偏于安全的;S-N曲线斜率负倒数m越小,疲劳损伤系数越大,采用较小m进行疲劳损伤系数计算偏于安全;对于影响线加载长度较短的构件,不考虑疲劳截止限计算的疲劳损伤系数更大,最大约为考虑疲劳截止限情况的1.36倍;影响线加载长度大于30 m时,疲劳截止限的影响可以忽略。In order to study the reasonable value of fatigue damage factors of the railway steel bridge,based on the damage equivalent principle in European code,an iterative calculation method was proposed to determine the equivalent stress amplitudes of the traffic fatigue loading history.A calculation method of the fatigue damage factor based on completely damage equivalent was put forward.The proposed method was applied and verified with the cases of 12 kinds of standard traffic loads in European code,and the results were compared with the results of the bi-linear S-N curve calculation method.The effects of tensile-compressive stress history and the S-N curve styles on the fatigue damage factors were discussed with the proposed method.The results showed that the bi-linear S-N curve calculation method generally overestimated the fatigue damage equivalence factors and the maximum deviation was 22.5%compared with European code.The results of the proposed fatigue damage factors calculation method agreed well with the European code with the 1.1%maximum deviation.The rationality of the proposed method was verified,and the value basis of fatigue damage factor in European code was revealed.It was safe to calculate the fatigue damage factor by using the stress amplitude without distinguishing the tension-compressive stress course.The smaller the negative reciprocal m of the slope of S-N curve was,the larger the fatigue damage factor was.It was safe to calculate the fatigue damage factor with the smaller m.For the components with shorter influence line length,the calculated fatigue damage factor without considering the fatigue cut off limit was larger,which was about 1.36 times of that considering the fatigue cut off limit.When the loading length of the influence line was longer than 30 m,the influence of the fatigue cut off limit was ignorable.

关 键 词：铁路 钢桥 疲劳损伤系数 损伤等效原理 影响线加载长度 迭代算法 

分 类 号：U441[建筑科学—桥梁与隧道工程]