基于BS 7910—2019标准的地铁车辆车体焊缝裂纹安全寿命评估  

Safety Life Assessment of Weld Cracks in Metro Vehicle Carbody Based on BS 7910-2019 Standard

作　　者：陈朝 张枝森 CHEN Chao;ZHANG Zhisen(Vehicle Branch of Shanghai Metro Maintenance Support Co.,Ltd.,200030,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200030

出　　处：《城市轨道交通研究》2024年第S01期12-17,共6页Urban Mass Transit

摘　　要：[目的]针对上海轨道交通铝合金车体焊接裂纹问题,探索科学合理的裂纹安全评估方法,这对保障列车的安全运营具有重要意义。[方法]通过BS 7910—2019中失效评估图和断裂力学理论,构建了一套适用于铝合金车体焊缝裂纹的安全寿命评估模型,并以上海轨道交通01A01型列车TC(带司机室拖车)牵引梁的10 mm焊缝表面裂纹为评估对象,进行铝合金车体焊缝裂纹安全寿命评估实践。[结果及结论]该车车体焊缝裂纹尺寸处于可接受的安全范围内,安全临界裂纹尺寸为45.8 mm,剩余安全寿命为3.8年。对该裂纹可采取每半年检查1次的维保策略,在列车退役前不必进行其他修复措施。评估模型已考虑到车体结构及载荷的复杂性,采取的保守估计方法能在确保安全性的前提下做到定量预测。评估模型可为生产实践提供指导,对裂纹状态管控红线的划定具有重要价值。建议在列车大修时,对车体进行全面的状态评估,包括车体探伤、材料分析、载荷数据收集,为后续裂纹安全寿命评估积累基础信息。[Objective]Addressing the issue of weld cracks in aluminum alloy metro vehicle carbody in Shanghai,it is essential to explore a scientifically sound method for crack safety assessment,which holds significant importance in ensuring the safe operation of trains.[Method]Utilizing the failure assessment diagram and fracture mechanics theory from BS 7910—2019 standard,a set of safety life assessment models applicable to weld cracks in aluminum alloy vehicle carbodies is constructed.Taking the 10 mm weld surface cracks in the traction beam of Shanghai Metro 01A01 model TC(trailer car with driver cab),evaluation on aluminum carbody weld crack safety life is carried out.[Result&Conclusion]The crack size in vehicle carbody weld is within the acceptable safety range,with a critical safe crack size of 45.8 mm and a remaining safety life of 3.8 years.It is recommended to adopt a maintenance strategy of inspecting the crack every six months,with no need for additional repair measures before the train is decommissioned.The assessment model accounts for the complexity of vehicle structure and loads,employing a conservative estimation method to achieve quantitative predictions while ensuring safety.The model guides production practices and holds significant value in delineating the control threshold for crack status.It is recommended to conduct comprehensive status assessments of the vehicle carbody during major overhauls,including ultrasonic testing,material analysis,and load data collection,to accumulate foundational information for subsequent crack safety life assessments.

关 键 词：地铁车辆 车体 焊缝裂纹 失效评估 断裂力学 安全寿命 

分 类 号：U270.3[机械工程—车辆工程]