Degradation Repairable System Reliability Modeling And Dynamic Preventive Maintenance Strategy

With the development of modern scientific and technological level of operation, the company’s manufacturing is moving in the way of intelligent, integrated and high-power direction trend. Especially in equipment system maintenance, repairable system reliability is one of the theoretical and practical engineering model. Because of increasing run time, it will accelerate the wear and tear of equipment to reduce the equipment life or resulting degradation. As the failure system reduce the working hours of equipment, and the number of failures will extend the service time of the corresponding system. Therefore, in the study of the recession repairable system reliability and optimal maintenance repair replacement strategy, how to conduct effective modeling, and select the appropriate maintenance strategies to reduce maintenance costs have an important theoretical and practical significance. From the points of the multiple failure system state and the fault correlation, the preventive maintenance strategies are discussed in the conditions of multiple state respectively. The main contents and achievements are as follows:Firstly, according to the general maintenance strategy, the various strategies in which long-term operating condition are classified, and then combined. Renewal reward theory is used to establish long-term operating conditions of the system cost. The recession factor and reliability is used for the new degradation repairable system, and the general model is transformed. The maintenance strategy which is in the condition of multiple state of the repair system as old is obtained by the model, and the optimum replace number and reliability of the system are investigated. It is found that recession factor and the relative maintenance ratio of the system is a linear relationship. The optimal replacement policy(N,R) is not affected by it.Secondly, based on the foregoing study, for the imperfect degradation of repairable system, the number of times each strategy of system failures are considered for the preventive maintenance strategies which is in order to build multi-state device. That is, two-dimensional(N1, N2) repair replacement policy. According to the numerical example, parameter factor analysis is used to verify the validity and accuracy of the model. The model is analyzed by the example, and the linear relationship between recession factor and the relative maintenance ratio is verified. It is also found that as an increase of the age decreasing factor a, it appears the monotonically increasing, and as an increase of recession factor b, it appears the monotonically decreasing.Finally, Fault Correlation isn’t taken into account in former discussion. The system model of the average maintenance costs is established in the long-term operating conditions. The optimum maintenance strategy selection criteria and minimum maintenance cost values are given in the failure distribution system under continuous conditions. The theory of Gumbel-Copula is used to obtain the change regular of fault relevance and reliability of system. Therefore, the research results are proved that in the actual conditions, degradation repairable system maintenance strategy has a certain theoretical guidance meaning and reference value.