摘要
本文通过实验获得S38C车轴的残余应力场、基本力学性能和断裂性能,采用表面单位压力法及二次迭代,在实物车轴中重建出径向梯度分布的压缩残余应力,基于实测载荷谱进行含缺陷S38C车轴的剩余寿命预测.分析结果表明:残余压应力对裂纹扩展有显著的抑制作用,深度小于4 mm的初始裂纹不扩展;经典Paris方程和NAS-GRO方程估算寿命分别约为28.5万公里和89.3万公里.当深度大于7 mm时,裂纹扩展速率迅速增大,因此,把7 mm作为S38C车轴损伤容限分析止裂判据比较合理.研究方法和结果对于含缺陷表面强化铁路车轴的疲劳强度及剩余寿命评价具有重要意义.
The compressive residual stress, basic tensile properties and fracture mechanics parameters of the surface-strengthened carbon steel axle (S38C) have been acquired experimentally and theoretically. The residual stress distribution at the radial direction of the axle was modeled by using the surface unit pressure method through two iterations. Based on measured loading spectrum, the residual life of damaged railway axles was simulated in the framework of fracture mechanics. It is found that the residual compressive stress has a considerable constraint on the fatigue crack propagation or opening. For the fatigue cracks lower than 4.0 mm initiated in the shaft, compressive residual stress still exists at the crack front. Once the crack depth is larger than 7 mm, the crack propagates rapidly. Therefore, the stopping criterion of the S38C axle is suitable with the crack depth 7 mm. Based on classical Paris equation and wellrecognized NASGRO equation, the predicted running mileages are 285000 km and 893000 km based on initial crack depth a=4.0 mm, respectively. The applied research method and results provide a significant theoretical reference to determine the fatigue strength and residual life of surface hardened high-speed railway axles with defects.
作者
秦庆斌
吴圣川
胡雅楠
刘宇轩
康国政
王文静
马利军
QIN QingBin;WU ShengChuan;HU YaNan;LIU YuXuan;KANG GuoZheng;WANG WenJing;MA LiJun(State Key Laboratory of Traction Power, Southwest Jiaotong University, Chengdu 610031, China;Key Laboratory of Vehicle Advanced Manufacturing, Measuring and Control Technology, Ministry of Education, Beijing Jiaotong University, Beijing100044, China;CRRC, Qingdao Sifang Co., Technology Centre, Qingdao 266111, China)
出处
《中国科学：技术科学》
EI
CSCD
北大核心
2019年第7期840-850,共11页
Scientia Sinica(Technologica)
基金
国家自然科学基金(批准号:11572267)
中国铁路总公司系统性重大项目(编号:P2018J003)
牵引动力国家重点实验室开放课题(编号:2018TPL_T03)资助
关键词
损伤容限设计
疲劳寿命
压缩残余应力
表面强化
高速列车
damage tolerance design
fatigue life
compressive residual stress
surface hardening
high-speed railway vehicle
