Research On Preventive Maintenance Strategy Optimization And Spare Parts Inventory Management Of EMU Components

With the first operation of China's new standard EMU on the Beijing-Shanghai line,it indicates that China's EMU design,R&D and manufacturing technology is realizing a leap from made in China to created in China.As a representative product of China's high-end equipment manufacturing industry,high-speed EMU has been put into operation in large quantities.To ensure the operation safety,reliability and maintenance economy of EMU is the focus of the operation management departments at home and abroad at present.The rationality of its maintenance plan will directly affect the safety and efficient operation of high-speed trains.At present,China's high-speed EMUs have entered the stage of high-level maintenance in large quantities.Therefore,this paper explores how to further formulate reasonable preventive maintenance plan for EMUs,while ensuring the reliability of their key components,to reduce the maintenance cost and the cost of spare parts inventory management consumed by maintenance.The specific contents of this paper are as follows:Firstly,considering the dynamic evolution of component reliability,the Weibull proportional reliability function is used to describe the reliability of a key component in the four-stage repair cycle replacement of EMUs when its operation status deteriorates to any mileage with the increase of service mileage.Through monitoring the reliability of components,the preventive maintenance threshold of components is taken as the decision variable,and the cost-effectiveness ratio is adopted.Analysis method to determine the specific mode of each maintenance.A two-stage imperfect preventive maintenance model based on time-dependent reliability is established to optimize the total cost of components in a replacement cycle.The preventive maintenance plan of EMU components in the whole service mileage is determined and compared with the current equal-cycle maintenance strategy.Secondly,on the basis of single component of EMU,taking multi-component mechanical series system as an example,the idea of opportunistic maintenance is introduced to optimize the maintenance plan of multi-component system,taking into account the economic correlation among components in multi-component system.By analyzing the evolution rules of component failure rate under two-stage imperfect maintenance strategy,the maintenance threshold between components is optimized without considering the economic correlation of components,and the preventive maintenance plan of component layer is obtained.Considering the economic correlation between components,the opportunity of preventive maintenance is used to optimize the mileage window of opportunity maintenance,and the maintenance plan of each component is merged to optimize the preventive opportunity maintenance plan of each component layer.Finally,on the basis of time-dependent reliability and spare parts inventory management strategy,the paper combines spare parts ordering strategy with spare parts preventive maintenance strategy,establishes the total cost mathematical model of spare parts ordering based on the preventive maintenance strategy of EMU components,optimizes the optimal maintenance plan of EMU components and determines the optimal order quantity and maximum spare parts.On the premise of ensuring the reliability of components,the joint optimization of maintenance strategy based on time-dependent reliability and spare parts ordering strategy can effectively reduce the maintenance cost of EMU components and the inventory management cost of spare parts.