ElectricWeldingMachineVol.53No.1Jan.2023第53卷第1期2023年1月基于DIC的焊接钢轨疲劳裂纹扩展特性研究张欣超1，彭飞1，2，张洪辉11.中车工业研究院有限公司，北京1001612.清华大学工业工程系，北京100084摘要：位于焊接钢轨轮轨接触表面以下5~25mm的次表面区域抗蠕滑载荷疲劳裂纹扩展能力的精确表征是合理制定钢轨打磨周期的基础。测试了焊接钢轨次表面母材及焊缝区域在不同应力比下的疲劳裂纹扩展速率，同时借助数字图像相关（DIC）技术捕获了不同条件下试样平面内实时应变特性，解析了母材及焊缝区域抗疲劳裂纹扩展能力及裂纹扩展过程中裂纹面及尖端变形特性。结果表明，相同条件下焊缝区域抗疲劳裂纹扩展能力更弱。低应力比条件下，裂纹扩展表现出更为显著的塑性诱导裂纹屏蔽效应。基于DIC测试获取试样面内变形特征，建立了疲劳裂纹扩展过程中裂纹面及尖端因塑性变形引起的局部应力受力模型。关键词：焊接钢轨；疲劳裂纹扩展；次表面；数字图像相关技术；扩展速率中图分类号：U270.4+1文献标识码：A文章编号：1001-2303（2023）01-0044-05StudyonFatigueCrackGrowthCharacteristicsofWeldedRailBasedonDICTechnologyZHANGXinchao1,PENGFei1,2,ZHANGHonghui11.CRRCIndustrialResearchInstituteCo.,Ltd.,Beijing100161,China2.SchoolofIndustrialEngineering,TsinghuaUniversity,Beijing100084,ChinaAbstract:Theexactcharacterizationofrailfatiguecracksgrowthabilityunderthecreeploadisthebasisforformulatingreasonablerailgrindingplan,thesecrackslocatedin5~25mmbelowtherailtread.Inthispaper,fatiguecrackgrowthrateofbasemetalandjointsunderdifferentstressratioweretested,real-timestraincharacteristicswerecapturedbyusingDIC(DigitalImageCorrelation)technology,fatiguecrackgrowthabilitiesbetweenbasemetalandjointsandcharacteristicsofcrackflanksandtipswereanalyzed.Theresultsshowthatthefatiguecrackgrowthabilityofjointisweakerthanthatofbasemetal,obviouscharacteristicsofplasticity-inducedcrackclosureareshownunderconditionofsmallstressratio.Then,alocalstressmodelaroundcrackflanksandtipsledbyaplasticzoneisestablishedbasedontheresultsofstraincharacteris‐ticsinthesamplesgotbyDICtechnology.Keywords:weldedrail;fatiguecrackgrowth;subsurface;DICtechnology;growthrate引用格式：张欣超，彭飞...
