地铁铝合金车体牵引梁裂纹原因分析及修复  

Analysis and Repair of Cracks in Drag Box of the Aluminum Alloy Metro Vehicles Body

作　　者：卢勇 黎澍 申天亮 Lu Yong;Li Shu;Shen Tianliang(Operation Division,Guangzhou Metro Group Co.,Ltd.,Guangzhou 510310,China)

机构地区：[1]广州地铁集团有限公司运营事业总部,广州510310

出　　处：《机电工程技术》2022年第12期301-305,共5页Mechanical & Electrical Engineering Technology

摘　　要：铝合金车体牵引梁是车辆受力关键部件,牵引梁裂纹对车辆运营安全及使用寿命产生重大影响。运用有限元法计算了牵引梁的受力,测试了轴箱振动量级以及车辆平稳性,采用电子显微镜观察了焊缝截面的微观结构,测试了焊缝区硬度,分析了裂纹产生的原因。对补焊修复、开孔去裂纹修复和铆接修复3种方法进行了分析和尝试,由于铝合金对焊接工艺要求较高、重复焊接对母材和原焊缝强度的削弱以及开孔对母材和焊缝受力产生不利影响等原因,补焊修复和开孔修复法都不能彻底解决裂纹问题。采用有限元接触分析法计算了两种铆接修复方案的应力分布情况,铆钉和母材强度符合要求,经过50万km以上实践检验,采用铆接修复的方式可以较好地解决牵引梁裂纹问题。The drag box of aluminum alloy car body is the key component of the metro vehicles.Cracksin drag box has a significant impact on safety and life of the metro vehicles.The stress of drag box was calculated by finite method.The vibration level of the axle box and the run quality of the vehicle were tested,the microstructure of weld cross section was observed by electron microscope,the hardness of weld zone was tested,the causes of crack were analyzed.Three methods include welding repair,crack removal repair and riveting repair were analyzed and attempted.Because of the high requirement of welding process,the strength of base metal and weld seam weakened by repeated welding and the negative effect of opening on base metal and weld,the crack could not be repaired completely by welding repair and cutting holes repair.The stress distribution of two riveting repair schemes was calculated by finite element contact analysis method.Rivet and base metal strength meet requirements.After more than 500000 km of practical tests,the method of riveting repair can better solve the problem of traction beam cracks.

关 键 词：铝合金 残余应力 有限元分析 焊接 开孔 铆接 

分 类 号：U260.32[机械工程—车辆工程]