Research On The Evaluation And Reliability Growth Of Aerospace Electrical Connectors Under Multi-ply Stress

In this master dissertation, took model Y11P-1419 electrical connector as the object, analyzed the failure mechanism under temperature and vibration stresses, and built the reliability model. Based on electrical contact theory , we did detailed and in-depth analysis on the failure mechanism of under environmental vibration and temperature stress , especially focus on contact resistance of electrical connectors. Proposed various measures to improve the contact resistance failure during structural design, production processes .The data from the first phase of accelerated life testing and the second phase of the enhanced testing the contrast showed that the measures were effective to improve the reliability of the electric connector and established the foundation for reliability growth model of the electric connectors.Firstly, introduced history and the current status of the reliability engineering, retrospected the reliability statistical analysis methods and development trends of domestic and international, gave a overview on comprehensive stress accelerated life test design methods and reliability enhanced test, reviewed the existing problems on aerospace connectors reliability study.Secondly, through analyzing the failure mechanism of electrical connectors under temperature and vibration stresses, educed the failure physics equation, made out the failure life distribution of electrical connectors and established the reliability statictical model which laid a foundation for working out electrical connectors' accelerated life test under multiple stresses.Thirdly, based on the constant stresses accelerated life test method, the testing times and the combined scheme of testing stresses by the uniformly orthogonal test theory and using the maximum likelihood method established optimum model of accelerated life test plan of electrical connectors under tempreture and vibration stresses. After the accelerate goal was satisfied, the model was optimized. The result about the optimized design of accelerated life test plan under multiple stresses of electrical connectors shows that the optimized test plan can get more data estimation precision, reduce test times, cut down the numbers of test- samples at the same degree of confidence and the test time is shortened largely. Fourth, Fifthly,statistically analyzed electrical connectors' accelerated life test data and obtained the electrical connector reliability estimated characteristic values.Fifth ,based on electrical contact theory ,we did detailed and in-depth analysis on the failure mechanism , especially focus on contact resistance of electrical connectors. Proposed various measures to improve the contact resistance failure during structural design, production processes. Thought over the cost,application environment,effectiveness,processing technology and concluded with a set of measures for the reliability growth test.Sixth, introduced reliability enhanced test, used this test to compare the date on the maximum stress level before and after the test, verified the the effectiveness of the measures , laid solid foundation for establishing the reliability growth model in the future.Eventually, gave a conclusion of the research content of the entire master dissertation, and proposed the future research content of electrical connector reliability test and the research direction of this foundation project.