Predictive Maintenance Decision Research For Civil Aero-engine

The engine is the heart of civil aircraft as a complex repairable system. Advanced maintenance strategy and technology are important for high safety, reliability and economics. Predictive maintenance is an advanced maintenance concept for complex systems such as the aircraft engine, which is gradually becoming technology realization from the theoretical research based on the support of the USA and the European Union. In this thesis, according to the features of civil aero-engine operation and maintenance, the concept of civil aero-engine predictive maintenance is introduced, some involved key technologies are studied in detail. With concrete examples, to verify the effectiveness of the method proposed in this thesis. The main research content is as following.(1) Based on the existing civil aero-engine maintenance decisions, discussed the meaning, the main modules and the key technologies of predictive maintenance for civil aero-engine, which laid a strong foundation for a deeper research in the future.(2) The reliability assessment of civil aero-engine has been studied. According to the features of civil aero-engine, such as high reliability, less failure data, Weibull distribution has been used to match the aero-engine life, and use Bayes method to estimate the relevant parameters. Meanwhile, the result has been solved by the software named Weibull++, which can help avoid the fussy iteration.(3) The remaining life prediction of the civil aero-engine has been studied. Hidden Markov process has been used to model the stochastic degradation process of the aero-engine combining with the monitoring and failure information. And the mode has been improved by aging factor, which can help predict the remaining life more exactly.(4) The predictive maintenance decision making has been studied. Based on the Hidden Markov process, proportional hazard model and Bayes method have been used to analysis the performance degradation of the aero-engine. The decision making process of the predictive maintenance has been given to minimize the expected average cost per unit time.Based on the research in this thesis, the accuracy of the aero-engine reliability evaluation can be increased, the prediction of remaining life can match the actual life more exactly. The related research achievement can be applied to the maintenance of the civil aircraft, which can improve the safety and maintainability of the aero-engine effectively.