Research On Reliability Modeling And Evaluation Methods For Key Components Of Aircraft

With the development of science and technology,there has been a continuous increase in the complexity of new types of equipment such as aircrafts and weapons,and new challenges have been faced in both maintenance theory and practice.The current equipment maintenance guarantee has changed from the initial passive(after failure)maintenance to planned maintenance and more advanced condition-based maintenance.Compared with the traditional passive maintenance methods,the condition-based maintenance has the advantages of strong pertinence,good maintenance effect and good economic benefits,and is widely used in the maintenance of aerospace,military equipment,As a result,predictive and health management technologies with broad application prospects.In PHM technology,the core problem of equipment protection and maintenance management is to accurately assess and predict product reliability and remaining lifetime.The traditional method is based on the product's lifetime data to predict its reliability and remaining lifetime,while the aerospace and military equipment often have the characteristics of high reliability and long lifetime(hereinafter referred to as high and long products),so if you want to Obtaining a large number of long-lifetime product lifetime data is usually obtained through a large number of experiments.However,due to constraints such as test cost and time,it is difficult to obtain sufficient lifetime-span data,which seriously restricts the development of PHM core technologies.During the use of high and long products,a large amount of lifetime-related performance degradation data has been accumulated.Due to the fact that the degraded data has the characteristics of easy access and economic feasibility of the experimental program,it has become an economically viable method to assess reliability and predict remaining lifetime.The work of this paper: First of all,in view of the shortage of equipment lifetime-span data,the general rules of performance degradation of aircraft equipment are discussed: First,the deteriorating trend is obvious and the deteriorating amount is accumulating;second,the deteriorating amount at each moment due to the effect of internal and external stresses with random uncertainty.Based on the law of performance degradation with the accumulated performance degradation data,a performance degradation model for high and long products was established.The parameters in the model were estimated by means of maximum likelihood estimation,and the reliability and remaining life of the model were evaluated,And using examples simulation to verify the effectiveness of the method.Second,when the obtained degraded data is insufficient,missing,or presents a small sample,it is difficult to ensure the accuracy of the prediction by simply using the degraded data to evaluate the product reliability.The different types of product lifetime information that will be produced during the trial and use of similar products,and the fusion of the product's degradation data and its lifetime information will help improve the prediction accuracy.This paper proposes two kinds of multi-source information fusion algorithms: First,using DS evidence theory to fuse the high and long product's lifetime data and performance degradation data.Second,to solve the problem of insufficient data degradation by integrating the lifetime data and the likelihood function of the degraded data,using Bayes The method obtains the reliability function and remaining life of the two methods.The effectiveness of the fusion method was verified by an example.Finally,using the mixed programming of C# and MATLAB language to integrate four kinds of reliability modeling and remaining lifetime prediction methods into one system software,which can make the research method more universal.