地铁车辆转向架构架服役寿命预测方法研究(上)

Research on the Prediction Method of Service Life of Frame of Metro Vehicle Bogie(Part 1 of 2)

基于名义应力的寿命评估方法,对某城市地铁A型车转向架构架开展服役寿命预测。建立构架有限元模型,参照相关设计标准,分析构架静强度和疲劳强度,识别构架结构的静强度和疲劳强度薄弱点位,作为服役寿命预测重点。在运营线路正线上开展车辆动应力试验,采集各点位在实际运行环境下的应力-时间数据。在对实测数据进行有效处理的基础上,结合Miner线性累积损伤理论,预测构架服役寿命。预测结果表明,A型地铁车辆转向架构架具备延期服役可行性。若维持当前运维条件不变,构架预期服役寿命可达43.2年。对于构架结构薄弱区域,在运维中应进行监控和重点检查,如定期状态检查或无损探伤等,以防出现严重的结构性裂纹或缺陷。有条件的话,可结合高级修修程对结构补强,以提升构架运用可靠性。

The service life of frame of the A⁃type metro vehicle bogie in a certain city is predicted using life assess⁃ment method based nominal stress.By establishing the finite element model of the frame and referencing to relevant de⁃sign standards,the static strength and fatigue strength of the frame are analyzed,and the weak points in structure of the frame are identified as the key points of service life prediction.The dynamic stress test of vehicle is carried out on the main operation line,and the stress⁃time data of each point in the actual operation environment are collected.On the ba⁃sis of effective processing of measured data,combined with Miner linear cumulative damage theory,the service life of frame is predicted.The prediction results show that it is feasible to extend the service life of frame of the A⁃type metro vehicle bogie.If the current operation and maintenance conditions remain unchanged,the expected service life of frame can reach 43.2 years.For weak areas in structure of the frame,monitoring and key inspections should be carried out in operation and maintenance,such as regular state inspection or nondestructive testing,to prevent serious struc⁃tural cracks or defects.If conditions permit,the structure of frame can be reinforced in combination with advanced modification procedures to improve the reliability of the frame utilization.