Research On Multi-stress Accelerated Test And Life Evaluation Technology Of Rudder Gear

High reliability and long life have become equipment development,especially the development goals and urgent needs of major equipment and major projects,which pose new challenges to traditional reliability technologies.As an effective means to ensure the high reliability and long life of equipment,accelerated life test technology has become a hot research topic.In order to improve the reliability of the electromechanical products of weapon equipment,make it more suitable for the harsh and complex service environment,and ensure the success rate of equipment operations,this paper studies the multi-stress accelerated test and life evaluation method of the steering gear of the typical electromechanical equipment of the missile.The main research contents are as follows:(1)For the steering gear system,failure modes,effects and criticality analysis and fault tree analysis are carried out.According to the structure and functional characteristics of the steering gear system,the steering gear system is divided into 4 sub-modules.Through the processing and analysis of the historical fault data of the steering gear,the fault data of products with similar structure is used for reference,and the function structure of the steering gear is used for reference.After reasonable reasoning,all the failure modes of the steering gear system are finally determined.Through the calculation and analysis of the risk priority number method,the harmfulness of each failure mode of the steering gear is determined.At the same time,the steering gear system is analyzed.Through qualitative analysis of the steering gear system’s fault tree,the minimum cut set of the steering gear system’s fault tree is determined,and the probability of occurrence of the rudder system’s fault tree top event is determined by quantitative calculation.And the weak link of the steering gear system.(2)For the multi-stress acceleration test of the steering gear,a section design method based on the determination of the limit load and the life analysis based on the threshold value is proposed.This method combines simulation and experiment.According to the determined test load,theoretical calculations determine the plastic strain limit when the steering gear fails.Through stepping load simulation,the limit values of the three stresses are determined and verified by bottom-testing.Using the obtained ultimate loads of the three stresses,the initial theoretical acceleration test profile is determined.According to the existing multistress acceleration model,an acceleration model suitable for temperature,humidity,and electrical three stresses is derived,the model parameters are solved by the simulation life value,and the test profile is corrected based on the acceleration ratio to determine the final test profile.After the profile design is completed,pass The test verifies the validity of the profile.(3)Using the acceleration test data of the steering gear,the remaining life of the steering gear is evaluated,and a neural network-based method for predicting the remaining life of the steering gear is proposed.This method uses the steering gear accelerated life test data.First,the data is standardized for analysis.The data is divided into two parts: training set and test set.Then,integrated SAE is used for deep feature extraction.The extracted depth features are subjected to feature evaluation and screening,leaving high-quality features,using the high-quality features as the input of the self-organizing mapping network to construct the health indicators of the steering gear,and finally using the particle filter model to realize the prediction and evaluation of the remaining life of the steering gear.