Research Of Multi-phase Preventive Group Maintenance Strategy On Electric Multiple Unit Component

How to evaluate the reliability of EMU and how to improve the reliability of it by the proper maintenance means have become the key factors to ensure the safety and reliability of the high-speed railways.Considering the feasibility and economy of the maintenance model,the paper puts forward the multi-phase group preventive maintenance strategy of the multi-component system,and analyzes the economics maintenance under different practical maintenance requirements.The specific contents of the paper are as follows:Firstly,based on the EMU field fault data,life distribution function fitting method is established by combining the enumeration method and the least squares method.Its validity is verified by K-S test.The lifetime distribution function of EMU system is given.Secondly,based on the economic dependence,the multi-component system of EMU is studied.Multi-phases preventive maintenance model is established.Comparison with the optimization of indirect group preventive maintenance model shows that multi-phase group preventive maintenance model can get lower maintenance costs to meet catenaries system maintenance tasks without increasing the maintenance labor intensity,achieve a better economic efficiency.Thirdly,the theory of failure dependence and shock model was used to perform internal and external modeling for two-component system.The computational experiments demonstrate that the multi-phase group preventive maintenance strategy can achieve a better economic efficiency,different phases of maintenance strategies for EMU maintenance department offers a variety of options for on-site implementation.The analysis of key sensitive parameters indicates that should appropriately increase high-level maintenance in the second half of the mileage and the adaptability of components' structure was improved according to the environmental characteristics.Then,dynamic-ordering policy was proposed and expanded the scope of application of multi-phases preventive maintenance.The ordering method can effectively solve the ordering problem of spare parts under bi-level imperfect maintenance.Comparison with the traditional order policy shows that dynamic-ordering policy was more closely with spare parts demand volume,can significantly reduce the number of orders and accurate the number of spare parts.The joint optimization of multi-phase preventive maintenance and dynamic-ordering policy can meet the reliability requirement at low cost.Finally,In order to explore the effects of maintenance parameters on maintenance economy,reasonably promoting the allocation of maintenance efforts.Assume that maintenance effort is linear with maintenance costs,multi-phase preventive maintenance model was established by minimizing the cost rate of the maintenance model.The analysis of sensitive maintenance efforts indicates that two-level maintenance can extend mileage of four-level maintenance and three-level maintenance can reduce the cost rate.