上海轨道交通车辆转向架构架裂纹原因及其扩展寿命分析  

Analysis of Causes and Extended Life of Cracks in Shanghai Metro Vehicle Bogie Frame

作　　者：张晨 ZHANG Chen(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52-56,共5页Urban Mass Transit

摘　　要：[目的]针对上海轨道交通车辆某型转向架构架齿轮箱悬挂座出现裂纹的问题,分析裂纹发生原因并计算其可扩展寿命。[方法]对裂纹部位切割取样后进行断口和金相分析,确定裂纹发生原因;建立该型转向架构架有限元模型,对构架静强度进行仿真计算,并计算裂纹处的应力值;基于断裂力学中的Paris公式计算该裂纹会发生快速扩展的临界长度,以及当前状态下扩展至临界长度的残余寿命;提出了相应的使用和维保策略。[结果及结论]该构架裂纹为焊接缺陷引发的疲劳裂纹,并扩展到了母材上;该裂纹处的设计强度满足要求;母材处裂纹的临界长度较短,扩展寿命较为有限。为避免该问题发生,构架制造时应加强检查,确保焊接质量;对有裂纹的构架在采取严密监控前提下可有条件使用,并尽快择机更换;对裂纹扩展至母材上的构架,须立即进行更换。[Objective]Addressing the issue of cracks in the suspension seat of the gearbox in a certain type of bogie frame in Shanghai Metro vehicles,it is aimed to analyze the cause of cracks and calculate their extendable life.[Method]The cracks are sampled,and fracture surfaces are analyzed to determine the causes of crack occurrence.A finite element model of the bogie frame is established to simulate the static strength and calculate stress values at the crack location.The Paris formula from fracture mechanics is employed to calculate the critical length for rapid crack propagation and the residual life until the crack extends to the critical length.Corresponding usage and maintenance strategies are proposed.[Result&Conclusion]The crack in the frame is caused by welding defects,extending to the base metal.The design strength at the crack location meets the requirements.However,the critical length of the crack in the base metal is relatively short,indicating a limited extended life.To prevent this issue,enhanced inspections during frame manufacturing to ensure welding quality are recommended.Frames with cracks may conditionally continue to be used under close monitoring,with prompt replacement planned.Frames with cracks extending to the base metal should be replaced immediately.

关 键 词：地铁车辆 转向架 构架 裂纹 金相分析 扩展寿命 

分 类 号：U270.32[机械工程—车辆工程]