Research On Modeling And Assessment Method Of Storage Reliability Of Space Relay

Aerospace relays are widely used in military equipment,and these equipment are often in storage for a long time.Therefore,it is necessary to accurately evaluate the reliability of aerospace relays during storage to ensure the reliability of weapon equipment in use.Aiming at the problem of high reliability and low life data of aerospace relay,this paper makes full use of the degradation parameters in the storage process to study its reliability.By analyzing its failure mechanism,the reliability of electromagnetic relay is evaluated with the degradation data of performance parameters obtained from accelerated storage degradation test.In order to accurately evaluate the reliability of aerospace relay,it is necessary to analyze its failure mechanism during storage.In this paper,by analyzing the storage environment of aerospace relay,contact surface corrosion failure and mechanical component failure are identified as the main failure modes.Principal Component Analysis(PCA)is used to reduce the dimension of degradation parameters,and the sensitive parameters of several degradation parameters are determined by box-line diagram,which lays a foundation for subsequent evaluation.Performance degradation data need to be obtained by accelerated storage degradation test.Based on the analysis of failure mechanism in Chapter 2,the types,stresses,stress levels,accelerated models,number of samples and test cycle of accelerated storage degradation test are determined.Then the overall design of the test system is introduced from the hardware and software parts,and the test results are analyzed,which provides data basis for reliability evaluation and life prediction of aerospace relay.In order to predict the storage life of aerospace relay at normal storage temperature,this paper uses the contact resistance data after wavelet denoising,combined with moving standard deviation and acceleration model to predict its life value.In order to evaluate the reliability of aerospace relays with multiple degradation parameters,a joint distribution function of contact resistance and suction time is established by using Copula function.The parameters in the function are estimated by using MLE method,and the reliability evaluation model is obtained by combining the failure threshold of degradation parameters.Aiming at zero failure of aerospace relay during long-term storage,this paper uses Bayes method to process performance degradation data.Firstly,the storage life distribution model of aerospace relay is determined,then the prior distribution is determined by Bootstrap method,then the posterior distribution expression is determined by Bayse formula,and the complex problem of posterior distribution is solved by MCMC method.The reliability evaluation model of aerospace relay is obtained.The reliability model based on Copula function and Bayes method are compared and analyzed to verify the validity of the model.