Life Cycle Oriented Civil Aero-engines Maintenance Occasion Optimization And Its Application

The service life of civil aero-engine can be several years.its operation and maintenance process is a correlated entirety,every maintenance will have an effect on subsequent operation and maintenance.Therefore,compare with traditional method,optimize the maintenance occasion of civil aero-engine from the perspective of life cycle can be more practically significant.Multiple impact factors need to be considered integrally to optimize the maintenance occasion of civil aero-engine.To overcome the deficiency of airlines in determining maintenance occasion of engine,this paper studies the maintenance occasion optimization problems of the civil aero-engine in its life cycle which take multiple impact factors into consideration.First of all,take the maintenance occasion optimization of civil aero-engine in its life cycle as a multiple life limit parts opportunity replacement problem from the perspective of life limit parts.Considering the economy and structure dependency of engine integrally,a multiple life limit parts opportunity replacement model is established.On the basis of analyzing model solution space,a reduction rule-based search algorithm is proposed,the algorithm can acquire the optimal solution of model.To improve the solve efficiency of algorithm further,a fast heuristic search algorithm is proposed.Then,the proposed algorithms are evaluated and validated by simulated data and the real-world data of the airlines.The results show that the proposed algorithms can effectively solve the multiple life limit parts opportunity replacement problem.Next,the maintenance occasion optimization of civil aero-engine is studied from the perspective of performance degradation.Through the observation of civil aero-engine performance degradation data,the author believes that the performance degradation of civil aero-engine can be divided into the rapid degradation stage and the normal degradation stage.The box-plot and the empirical mode decomposition method is utilized to preprocess the performance parameters of the aero-engine,then time series data clustering and regression analysis method is adopted to extract the degradation patterns in these two stages.Considering the operation cost and maintenance cost integrally,the maintenance occasion optimization model of civil aero-engine based on performance degradation is established.The optimization objective is to minimize the operation and maintenance cost of each unit and particle swarm optimization algorithm is utilized to solve the model.Based on the above research,the impact of hardware damage,airworthiness directive and service bulletin is analyzed,a maintenance occasion optimization method of civil aero-engine based on local optimization is proposed.Real-world data of airlines are utilized to verify the proposed method.The results indicate that the proposed method can adjust and optimize the maintenance occasion of civil aero-engine in its life cycle.Finally,according to the practical engineering requirements of airlines,the author develops core business components of maintenance occasion optimization of civil aero-engine on the basis platform of customizable aero-engine health management and maintenance decision support system.The developed components can provide technical supports for airlines on the work of short-term engine removal date prediction,medium-term and long-term engine removal quantity prediction and engine maintenance occasion optimization in its life cycle.