上海轨道交通1号线车辆构架裂纹产生原因探究

On the Causes of Frame Crack in Shanghai Metro Line 1 Vehicles

针对上海轨道交通1号线转向架构架横梁和侧梁连接处出现裂纹的问题,建立了地铁列车转向架构架有限元模型,并对构架静强度进行了仿真计算,同时校核了对接焊缝处的疲劳强度。通过宏观形貌、化学成分以及力学性能分析,找到了该构架产生裂纹的具体原因:主要是对接焊缝处存在未熔合和未焊透的缺陷,导致构架产生疲劳裂纹。同时提出:在构架制造及日常维护时,应增加相应的检查。

For the cracking problems existing on bogie frame beam and side beam joint in Shanghai metro Line 1 vehicles, a finite element model of subway train bogie frame is established, the bogie frame static strength is simulated and calculated, the butt weld fatigue strength is checked. Through maceoscopic morphology, chimeical composition and mechanical property analysis, the exact causes for the frame cracks are finded, due to the fault fusion and pene- tration defects in butt weld, fatigue cracks in the frame- work are prone to occure. Suggestions are put forward to add more strict checks in the manufacture and daily mainte- nance of bogie frame.