Research On Opportunity Maintenance Strategy Of EMU Bogie System Based On Integrated Importance Measure

With the rapid development of China high-speed railway,more and more EMUs have been put into operation,and a large number of EMUs in the early have been entered the maintenance stage.The current EMU repair system is mainly based on regular maintenance and supplemented by unscheduled minor repair,where exist the problems of "insufficient maintenance" and "excessive maintenance" to a certain extent.Insufficient maintenance will make the passengers feel uncomfortable or dissatisfied when riding,and even can not guarantee the reliability and safety of EMU operation.Excessive maintenance will cause a lot of waste of human and material resources,even occupy the normal running time of EMU trains,which makes the dispatching difficult and the operating cost high.In order to further identify the key components in the bogie system,improve the reliability and reduce the maintenance cost,an opportunistic maintenance decision-making model of EMU bogie system based on integrated importance measure is established,and it is optimized with availability as the constraint condition.Based on the above,this paper mainly studies the following problems:(1)According to the historical fault data statistics,the bogie fault tree system is established and analyzed quantitatively.Based on the statistical probability of the bottom event,the failure probability of the middle event and the top event is calculated,and the probability importance,critical importance and structural importance of the bogie subsystems are further calculated,and the reliability is allocated according to the critical importance.The probability of component state distribution and component state transition rate are introduced to establish the calculation model of component integrated importance measure,and the importance analysis method is applied to the maintenance decision of EMU bogie system.(2)The integrated importance measure of the bogie subsystems is calculated,and the maintenance priorities are sorted accordingly.The optimal maintenance period and time of subsystems are calculated with the goal of minimum total maintenance cost in the replacement cycle.Taking the maintenance time of the key subsystem as the maintenance downtime of the bogie system,the opportunity maintenance window is introduced to merge the maintenance time of the subsystems.With the goal of minimizing the total maintenance cost of the bogie system,the opportunity maintenance model of the bogie system considering the integrated importance measure is established.Then,given the maintenance parameters of EMU bogies,the simulation calculation is carried out to find the corresponding mileage window value when the total maintenance cost of bogie system is the lowest,and the comparison analysis is carried out with the opportunity maintenance model of bogie system without considering the integrated importance measure.(3)Availability is one of the important indicators to measure the EMUs maintenance effect,and the system maintenance duration directly determines the revenue of operation.Therefore,the opportunity maintenance model of EMU bogie system based on integrated importance measure is optimized with availability as the goal.The optimal maintenance period and time of subsystems are calculated with the goal of maximum availability in replacement period.Taking the maximum availability of the system as the goal and the maintenance time of the key subsystem as the maintenance time of the system,the opportunity maintenance model of the bogie system considering the integrated importance measure under the availability constraint is established.Given the maintenance parameters of EMU bogie,the simulation calculation is carried out to find the corresponding mileage window value when the total maintenance cost of bogie system is the lowest.which not only ensures the availability of the system,but also reduces the maintenance cost and improves the reliability.