U71Mn钢轨振动疲劳寿命研究  

Vibration Fatigue Life of U71Mn Rail

作　　者：钟雯[1] 胡家杰 刘启跃[3] ZHONG Wen;HU Jiajie;LIU Qiyue(School of Mechanical Engineering,Xihua University Chengdu,610039,China;Avic Chengdu Aircraft Industrial(Group)Co.,Ltd.Chengdu,610092,China;Tribology Research Institute,Southwest Jiaotong University Chengdu,610031,China)

机构地区：[1]西华大学机械工程学院,成都610039 [2]成都飞机工业(集团)有限责任公司,成都610092 [3]西南交通大学摩擦学研究所,成都610031

出　　处：《振动．测试与诊断》2022年第5期893-897,1032,共6页Journal of Vibration,Measurement & Diagnosis

基　　金：国家自然科学基金青年科学基金资助项目(51405395);国家重点研发计划资助项目(2016YFB1102601)。

摘　　要：随着中国铁路的快速发展,钢轨的服役寿命对于降低铁路运行成本、提升运营安全显得日益重要。以高速铁路常用的U71Mn钢轨材料为对象,研究其存在疲劳裂纹时不同初始应力强度因子条件下的振动疲劳寿命并分析其破坏机理。结果表明:不同初始应力强度因子对于U71Mn钢轨的振动疲劳寿命影响较大;振动疲劳裂纹在U71Mn钢轨当中的扩展机理与静态疲劳也有所区别。在疲劳瞬断区,振动疲劳断口河流花样更密集,韧窝更大更深;在疲劳裂纹扩展区,初始应力强度因子较大时低周疲劳损伤机制占主导,初始应力强度因子较小时则高周疲劳损伤机制占主导。With the rapid development of Chinese railways,the service reliability of rails has become increasingly important for the reduction of railway operation cost and improvement of operation safety.In this paper,a kind of cantilever structure is used to carry out the tests to study the vibration fatigue life and analyze its failure mechanism under different initial stress intensity factors when there is fatigue crack in U71Mn rail materials.The results show that the different initial stress intensity factors have great effect on the vibration fatigue life of U71Mn rails.By comparison,it is found that the propagation mechanism of vibration fatigue cracks in U71Mn rails is also different from the static fatigue.In the fatigue transient fracture zone,the vibration fatigue fractures have denser river patterns and larger and deeper dimples.In the fatigue crack propagation zone,when the initial stress intensity factor is large,the low-cycle fatigue damage mechanism dominates;when the initial stress intensity factor is small,the high-cycle fatigue damage mechanism dominates.

关 键 词：振动疲劳 疲劳寿命 疲劳曲线 断裂机理 

分 类 号：TH114[机械工程—机械设计及理论]