The Research On Maintenance Decision Of EMU Gearbox Based On Reliability Analysis

Scientific and reasonable maintenance system is an important guarantee for the stable operation of EMU.Gearbox,as the power transmission device of EMU,directly affects the safety and reliability of vehicle operation.Preventive maintenance in practical engineering is prone to problems such as "insufficient maintenance","excessive maintenance,and inaccurate timing of condition maintenance.Based on these,this paper puts forward reliability-based maintenance decision-making methods for EMU gearbox,which study from three aspects:maintenance mode decision-making,planned maintenance cycle decision-making and condition maintenance timing decision-making,establish relevant maintenance decision-making models,comply implementation procedures and conduct maintenance decision-making research according to the results.The procedures provide references for the optimization of gearbox maintenance system.The main work are as follows:(1)In order to determine the weak links of the gearbox system,HyperMesh is used to establish finite element model,and static strength analysis is carried out in ANSYS.Combining with the results of FMEA analysis,the components prone to failure are determined.Entropy weight method is used to evaluate the important functional components of gearbox,and the maintenance modes of the important components are determined accordingly.(2)Aiming at the insufficient or excessive maintenance of gearbox,a hybrid failure rate evolution model is used to describe the change of system failure rate before and after planned maintenance.The optimization models of planned maintenance cycle based on reliability,availability and maintenance cost are established respectively and realized by programming to solve the optimal maintenance cycle.The BP neural network based on genetic algorithm optimization and genetic simulated annealing algorithm optimization are used to establish the prediction models of gearbox failure rate.The model with high accuracy is used to predict the gearbox failure rate,which provides data reference for preventive maintenance.(3)In view of the inaccurate timing of condition maintenance,a Weibull proportional risk model is established to describe the real-time operation status of gearbox system.Aiming at availability and maintenance cost respectively,optimization models of condition maintenance timing decision-making are established and solved.According to the condition of condition maintenance decision-making and real-time monitoring data,the optimal timing and threshold of condition maintenance are obtained.(4)With VB as the basic development tool and Access as the background database,the software for EMU gearbox maintenance analysis is developed.Through data management,strength analysis,fault analysis and maintenance analysis modules,the decision-making function of maintenance mode,planned maintenance cycle and condition maintenance timing of gearbox are basically realized.