Research On Reliability And Replacement Strategy Of Aviation Equipment Based On Imperfect Maintenance

Reliability and maintenance strategy is an important factor affecting the operation and maintenance of aviation equipment and subsystems.In practical engineering,the reliability and maintenance strategy after repair are important data of equipment system.According to the investigation,the repair based on imperfect is more in line with the actual repair situation.This paper analyzes how to describe the imperfect repair process of the whole life cycle of the equipment system,the actual availability of imperfect repair and the replacement strategy.Based on the actual engineering requirements,this paper determines the imperfect maintenance model of equipment and subsystem according to the quasi-renewal theory,and constructs the availability and replacement strategy model of the system.This paper is based on the selected imperfect maintenance model,and its main contents and achievements include:First of all,the imperfect maintenance model and strategy of aviation equipment are selected,and the maintenance cost model of the equipment system is given when the decision variable is the period of preventive maintenance and the number of imperfect repairs between two preventive maintenance.The cost model is used to optimize the replacement strategy,and the availability of the best replacement strategy is verified.Later,based on the imperfect maintenance model,the optimal spare parts prediction algorithm is given.According to the characteristic that the system will gradually deteriorate with the decrease of uptime and the increase of maintenance time,the upper and lower bounds of system availability are given by using the quasi-renewal theory.At the same time,the optimal demand for spare parts is given by numerical calculation.The annual purchase quantity of spare parts is optimized to meet the requirements of operational availability.Thirdly,the maintenance strategy of the deteriorating system considering the quality assurance is studied,and in order to highlight the importance of non-negligible maintenance time in warranty cost analysis,a fixed warranty model is constructed and compared with the cost model which ignores the maintenance time.At the same time,an extended warranty service model is built to study the costs of the system supplier and user.Among them,the contractor provides the extended warranty option for the user with two replacement strategies.Then,based on the average cost per unit time,the benefit analysis of the contractor is carried out.Finally,the replacement strategy of multi-state system under imperfect maintenance is studied.In practical engineering,the implementation of system maintenance plan is not determined by the state change of some components in the system,but by the trend of the performance state change of the whole system.Therefore,an optimal replacement strategy is given according to the "overall performance" of the polymorphic system,while ensuring the maximum average benefit per unit time.