城市轨道交通车辆抗侧滚扭杆座区域裂纹成因分析及修复方案  

Cause Analysis and Repair Scheme of Anti-roll Bar Mounting Area Cracks for Urban Rail Transit Vehicle

作　　者：李济棋 吕晟 LI Jiqi;LYU Sheng(Vehicle Branch of Shanghai Metro Maintenance Support Co.,Ltd.,200237,Shanghai,China)

机构地区：[1]上海地铁维护保障有限公司车辆分公司,上海200237

出　　处：《城市轨道交通研究》2023年第S01期24-30,共7页Urban Mass Transit

摘　　要：上海轨道交通1号线某原装进口车型的抗侧滚扭杆座区域裂纹频发,危及列车运营安全,探索裂纹成因并制定合理修复方案对保障运营安全具有重要价值。采用有限元模拟、理化分析等手段,从材料、设计、焊接质量等因素综合分析抗侧滚扭杆座的裂纹成因,并制定相应的修复方案。结果显示:抗侧滚扭杆座的关键焊缝均能满足静强度要求;车辆底板厚度为2.5 mm,不能满足设计要求;部分7020铝合金在服役二十多年后,出现材料屈服强度下降的现象;部分焊缝存在交叉,且焊接区域存在明显未熔合、微裂纹、孔洞、疏松等缺陷。设计不合理为产生焊缝裂纹的主因,焊接质量缺陷、材料强度下降也是导致7020铝合金开裂的重要因素。修复方案验证表明,该方案能够满足运营需求,可为延长车体服役寿命打下基础,为新车的车体设计提供借鉴。Cracks occur frequently in the anti-roll bar mounting area of an original imported model of Shanghai Rail Transit Line 1 train,which seriously endangers the train safety.It is of great value to explore the causes of cracks and formulate reasonable repair scheme to ensure the operation safety.By means of finite element simulation and physical-chemical analysis,the causes of anti-roll bar mounting area cracks are comprehensively analyzed from factors such as material,design and welding quality,and the corresponding repair scheme is devised.The results show that the key welds of anti-roll bar mounting area can meet the static strength requirements;the thickness of vehicle bottom plate is 2.5 mm,which doesn’t meet the design requirements;the yield strength of some 7020 aluminum alloy has decreased after more than 20 years of service;cross of some welds are found,and there are obvious defects such as lack of fusion,micro cracks,holes and porosity in the welding area.The main reason of weld cracks is unreasonable design.Welding quality defects and material strength decrease are the important factors leading to 7020 aluminum alloy fracture.It is verified that the repair scheme can meet the operation requirements,laying a foundation for carbody service lifespan extension and providing reference for the carbody design of new trains.

关 键 词：城市轨道交通 车辆 抗侧滚扭杆座 7020铝合金 裂纹修复 焊接质量 

分 类 号：U270.12[机械工程—车辆工程]