| As a new member of EMU family,cr200 j power centralized EMU has been put into operation on Lanzhou Chongqing railway in early 2019,marking the beginning of the upgrading of China’s railway common speed trains.But with the rapid development of domestic high-speed railway network.At present,the power centralized EMU has been operated on many Trunk Railways.With the large-scale application of power centralized EMU,its maintenance problem has become an urgent problem to be solved by vehicle maintenance department.There are obvious differences in fault characteristics and maintenance strategies between power centralized EMU and power decentralized EMU,which need targeted analysis and research.As the core component of rail vehicle,the reliability of bogie is very important for the safety of vehicle operation.At present,in the actual maintenance of power centralized EMU bogies,the traditional preventive maintenance strategy is still followed,which can not accurately grasp the opportunity of condition based maintenance,resulting in "insufficient maintenance" and "excessive maintenance".In order to improve the reliability of the bogie system and reduce the maintenance cost,it is particularly important to study and analyze the reliability of the bogie system and the maintenance mode decision.In this dissertation,the bogie system of cr200 j EMU is analyzed as follows(1)This dissertation expounds the equipment characteristics,current operation environment conditions and operation quality of cr200 j EMU.The structural composition of bogie(sw220k)system is described,the functions and failure modes of various parts of bogie system are analyzed,the failure mode and effects analysis(FMEA)of bogie system is established,and then the fault tree model of bogie system is constructed.(2)Based on the basic knowledge of Bayesian network and fuzzy set theory,the fault number model of power centralized EMU bogie system is transformed into Bayesian network model.Fuzzy set theory is used to solve the problem that the accurate failure probability of the root node can not be obtained due to the incomplete fault record data of the bogie system.The noisy or model is applied to modify the conditional probability of some intermediate nodes,which greatly reduces the number of parameters used to construct conditional probability distribution.The weak link of bogie system is found,which provides reference for the next work.(3)On the basis of system reliability analysis,the maintenance importance of each component of bogie system is quantitatively analyzed,and the evaluation method based on improved risk priority number is proposed.According to the risk priority value of each component of the system,the maintenance mode selection is decided.In order to improve the availability of centralized EMU and reduce the maintenance cost,a feasible maintenance decision-making method is provided. |
