System Reliability Evaluation And Maintenance Strategy Optimization For Rail Transportation Train Considering The Interaction Of System Components

Rail transportation train system is a typical complex electro-mechanization system,which has multiple and large number of components. The components state is various and the function relationships among components are different. It is difficult to reflect complex organization structure and the coupling relationships of rail transportation train system for tranditional methods of reliability modeling and estimation. Besides, at present the main maintenance strategy for rail transportation train in our country is preventive periodic maintenance and remedial maintenance, which generates large amounts of problems of insufficient maintenance of failure components and excessive maintenance of unexpired components.Based on the above problems, system reliability evaluation and maintenance strategy optimization for rail transportation train considering the interaction of system components was carried out in this paper, which included the following four aspects:(1) Reliability modeling orientes functional behavior for rail transportation train systemThe research started from the relationships among system components and whether the relationships were existed or not. The model was constructed in this paper, which oriented functional behavior and corresponded to the actual objects of rail transportation train system. The components and their mechanical properties, electrical properties and information properties were taken as the nodes. In addition, the relationships among components and their mechanical properties, electrical properties and information properties were taken as the edges. The reliability model constructed in this paper can integrallty represent the topological structure and interaction relationships among components for rail transportation train, which provided one kind of scientific and practical method to model and estimate the reliability of complex electro-mechanization system.(2) Reliability evaluation of rail transportation train system based on Copula-NetworkCopula function was adopted to represent the relationships among components based on the network model, which solved the nonlinear and complex problems about the relationships among components for rail transportation train system. The relialibity evaluated methods were studied for two types of systems, which the components were all independent of each other and the relationships among components were existed. Besides,considering whether the relationships among components were existed or not and whether the relationships were beneficial to maintain system function, the adaptive coefficient of maintenance strategy ?1 was introduced. The general evaluated method for rail transportation train was proposed by the convex combination of two extreme cases, such as R(t) = ?1 min[Rc(t), R0 (t)] + (1 - ?1) max[Rc (t),R0 (t)]. Combining with trandational reliability evaluated method,the method proposed in this paper can satisfy higher requirement of balance between safety and economy for industry, and had more practical significance, which provided theoretical basis for scientifically evaluating the train reliability, the construction of RAMS model and the decision of suitable maintenance strategy.(3) RAMS model construction for rail transportation train systemRAMS' basic meaning of rail transportation train system and the internal logic relationship among reliability, availability, maintainability and safety was analyzed.Multiparameter measurement sets were built for the components' maintenance strategy and the system's maintenance strategy. Considering the improvement of components'performance given by maintenance action, the models of availability and safety were obtained by detailed mathematical derivation, which realized the completely representation of RAMS for rail transportation train system. At the same time, the model basis was provided for maintenance stategy optimization based on RAMS.(4) Comprehensive coverage maintenance strategy based on RAMS for rail transportation train systemBased on the analysis of contradiction among reliability, availability, maintainability,safety and maintenance strategy, RAMS' models were adopted simulated annealing-particle swarm optimization algorithm. Three types of maintenance strategies were studied, which included the maintenance strategy oriented improving availability, the maintenance strategy oriented ensuring safety and the maintenance strategy oriented reducing maintenance cost under the condition of satisfying the limited availability and safety. Combining the difference among the transport capacity and maintenance resources for high-speed train and urban railway system, a whole set of pervasive maintenance strategy was proposed based on RAMS for rail transportation train system, which can satisfy the different transport capacities and requirements of maintenance cost. It was conducive to realize the balance of safety, availability and economy, which provided the theoretical foundation for the initiative maintenance of rail transportation train system and had important theoretical value and practical significance.