Reliability Analysis Of Diesel Engine Based On 4F Integration Technology

Traditional reliability management and analysis technologies such as FHA(functional hazard analysis),FMECA(failure modes,effect and criticality analysis),FTA(fault tree analysis)and FRACAS(failure reporting,analysis and corrective action system)have their own key points.When analyzing the reliability of the whole equipment system,they often miss something in the analysis process,making the analysis efficiency low.How to improve the efficiency of reliability analysis and the comprehensiveness of the analysis process is a problem facing engineering practice.According to the characteristics of FHA,FMEA,FTA and fracas,this paper designs a reliability analysis method based on 4f integration technology.The practical problems encountered in the reliability analysis of a new type diesel engine in the scheme design stage are systematically studied.The main research results in this paper are as follows:1)A new repairable dynamic fault tree analysis method(RDFTA)is proposed in this paper according to the maintainability of diesel engine.Based on Markov Repairable System Theory,the quantitative calculation formula of dynamic logic gates is established.The accuracy of the method is verified by Monte Carlo simulation.The simulation results show that the RDFTA method has the advantages of short running time and simple analysis steps in complex system reliability modeling.At the same time,a series of studies are carried out on the common cause failure of redundant structures in repairable systems.Based on RDFTA,a new explicit modeling method for deterministic CCF and probabilistic CCF is proposed.The accuracy of the method is verified by GO method.The validity of the method is verified in the reliability modeling of the electronic control system of diesel engine in the scheme design stage.Aiming at the existing problems of 4F technology,a new reliability analysis method based on 4f integration technology is proposed in this paper.The analysis depth of each technology in complex system is planned in detail,the operation mode of 4F integration technology is optimized,and the application structure of FRACAS in 4f integration technology is optimized.In the system level fault identification formula,a FMECA-FHA integrated model is proposed,which uses TOPSIS algorithm and WRSR algorithm to optimize the evaluation accuracy of FMECA and FHA respectively.The FMECA analysis results of the physical level of the key components of the system are verified by finite element simulation.The endurance life of the turbine impeller in the test is predicted according to the failure threshold,which simplifies the steps of reliability analysis of the new model diesel engine in the scheme design stage,and provides a new research idea for the reliability analysis of the new system.2)In view of the low efficiency and tedious steps in the process of reliability analysis,this paper uses the idea of modularization and the Pt Qt5 Library in Python programming language to complete the design and development of 4F integration technology(comprehensive application of reliability analysis technology)platform system.ANSYS-fluent,Workbence,True Grid,Python and other software are connected through the GUI interface.The working principle mainly relies on reliability parameter modeling,reliability risk sequencing and simulation parameter simulation to evaluate the reliability of complex systems.The system has the functions of repairable system reliability calculation,system fault mode risk assessment,fault physical simulation and so on.It is a comprehensive reliability evaluation system integrating data analysis,visualization and parameter simulation.The source code of the reliability analysis system has good extensibility and stability.The analysis system can be further expanded according to the needs of the actual situation.The system greatly reduces the tedious calculation process in reliability comprehensive analysis and improves the work efficiency of reliability analysts.