A Study About Degradation Modeling And Centralized Replacement Strategy Of Railway Wagon Brake Shoe

Since heavy-duty railway wagons play an important role in the freight system of China,the safety and stability of its transportation have attracted extensive attention.As an important part of the brake device,the wear amount and failure probability of brake shoe increase with the mileage of service,which brings great hidden hazard to the braking safety and transportation stability of railway freight car.On the other hand,due to the lack of exploration of brake shoe degradation and failure patterns during the use of wagons,the current brake shoe maintenance strategy is relatively straightforward.Therefore,based on the collected field data of railway wagon brake shoe wear,this thesis studies the degradation process and failure patterns and develops the maintenance strategy of brake shoe under the centralized replacement mode.First of all,this thesis analyses characteristics of brake shoe wear data.The data indicates that the overall degradation trend of brake shoe is significant,however,the individual degenerate discreteness is also significant.The generalized linear model with Gamma function is employed to model the degradation process data and adjust the heteroscedasticity.Secondly,the characteristics of the current brake shoe maintenance mechanism are explored,and the main problems of the current brake shoe temporary maintenance are analyzed.Considering the engineering constraints,this thesis proposes a centralized repair mode,establishes a hybrid repair strategy simulation model considering temporary repair and centralized repair,and determines the optimal replacement times under the hybrid repair strategy.Finally,on the basis of the hybrid repair strategy,a reliability maintenance cost multi-objective repair strategy model is established considering the factors of brake shoe reliability and maintenance cost.Through case application,the optimal replacement times of brake shoe,the mileage interval and thickness threshold under the optimal replacement times are solved.Compared with the traditional brake shoe maintenance strategy,the maintenance strategy in this thesis reduces the number of temporary maintenance and improves the utilization rate of brake shoe.The research results of this thesis are helpful to realize the precise repair of brake shoe.