Research On Reliability Evaluation And Optimization Of EMU System

In recent years,high-speed rail industry has developed vigorously,and fast and convenient EMUs are gradually becoming the first choice for people to travel.However,the structure and function of the EMU are complex and the operating environment is diverse.How to ensure the safe and stable operation of the EMU under the conditions of high speed and high load is more and more important for its reliability research,especially the reliability research of the whole train level is for railways Transportation has more realistic significance,so this paper mainly carried out the following research:Comprehensive comparative analysis of the reliability index system of foreign EMUs,combined with the current status of EMU safety management in my country,defines the EMU fault classification level and clarifies the statistical calculation method of the failure rate index.According to the structural and functional analysis of the EMU general system,the reliability model of the entire EMU and key system is established,and the reliability calculation formula under the corresponding model is given.In summary,the four reliability allocation methods that can be applied to the EMU are summarized,the formula of the relative failure rate ratio allocation method under the parallel system is extracted,and the three reliability allocation methods are described in detail with engineering calculation examples.The failure rules of the EMUs on the main platforms are verified.The verification results show that,in addition to eliminating the influence of abnormal factors such as dominant failures and obvious early failures,the failure rules of the entire EMUs are approximately subject to an exponential distribution;Group failure rate prediction and verification methods,combined with statistical data,give different failure rate grade suggestion tables and verification tables for the entire vehicle and the system,and put forward the corresponding EMU reliability verification scheme.According to the analysis of different levels of failures of the same model,it is found that the safety and punctuality rate of EMUs in China are basically guaranteed,but the failure rates of category B and category C are relatively prominent;analysis of failures of different functional systems of the same vehicle model finds traction,braking,and bogie The failure rate of systems with complicated structures is relatively high,and the reliability of related systems needs to be further improved.At the end of the thesis,the FMEA-based EMU reliability optimization prediction is carried out.The prediction results show that effective measures can be taken to reduce the EMU failure rate andimprove the EMU reliability by taking effective measures for the relatively high proportion of faulty products or failure modes.