The Contact Reliability Design Modeling And Test Evaluation Of Wire Spring-type Electrical Connector

As a key component in the model equipment,the wire spring-type electrical connector is mainly used to realize the transmission of electrical signals.A common failure mode is contact failure,which causes the electrical signal to be lost or error during transmission.As a result,the entire model equipment cannot work normally,the contact reliability of the wire spring-type electrical connector has an important influence on the overall reliability of the model equipment.According to the statistics of the electrical connector users,67%of the failures of the electrical connectors are design and process problems.At present,for the design of the wire spring-type electrical connectors,the qualitative design method is generally used to extend the life.It is impossible to determine whether they meet the high reliability and long life requirements of current models equipment.Therefore,it is necessary to carry out the research on the contact reliability design modeling and test evaluation of wire spring-type electrical connector,to provide technical support for the development of high reliability and long life wire spring-type electrical connectors and meet the requirements of the model equipment.In this thesis,a wire spring-type electrical connector is used as a research object,and the contact reliability design modeling and test evaluation of the wire spring-type electrical connector are carried out.The specific research contents are as follows:1.The contact failure mechanism of a wire spring-type electrical connector under storage environment was studied:Based on the actual storage environment of the model equipment,the environmental stress that accelerated the degradation of the contact performance of the wire spring-type electrical connector was determined to be temperature.The manifestation of contact failure is the increase in contact resistance above the failure threshold.The mechanism of the increase in contact resistance is the oxidation reaction on the surface of the contact and the stress relaxation of the wire spring.2.The contact reliability design model of the wire spring-type electrical connector is established:Based on the contact failure mechanism of the wire spring-type electrical connector,the growth law of the oxide film on the surface of the contact is determined according to the reaction theory model.From the mechanical model of the contact and the thermal activation process of the stress relaxation of the wire spring,the stress relaxation law of the wire spring is determined,finally,an accelerated degradation model of contact performance of the wire-spring electrical connector was established,including elastic modulus,pin diameter,wire spring diameter and length.Based on the proportional effect model,considering the randomness of the design parameters of the contact and the characteristics of the contact performance degradation,the reliability model of the contact was determined.Based on the structural characteristics of the wire spring-type electrical connector,the reliability model of the contact is used to determine the contact reliability statistical model of the wire spring-type electrical connector.The contact reliability design model of the wire spring-type electrical connector is determined by the contact reliability statistical model and the accelerated degradation model.3.The wire spring-type electrical connector acceleration test scheme under constant stress is determined:Based on the accelerated degradation model of contact performance of the wire spring-type electrical connector,according to the product characteristics of the wire spring-type electrical connector and the variation characteristics of the monitored performance parameters,the four stress levels are set,105?,120?,140? and 158? respectively.Under the stress level,the contact resistance and contact pressure of the electrical connector were investigated.The change of the contact resistance was monitored by the method of equal interval test.The change of the contact pressure was monitored according to the principle of "first dense and then sparse".4.The statistical analysis of the test data is completed:First,use the least squares estimation method to obtain rough estimates of model parameters in the contact reliability design model of electrical connectors.Then based on the normality of the measurement error of the test data and the difference in the degradation of contact performance,write the maximum likelihood function of the model parameters,and use the rough estimate of the model parameters as the initial value to obtain the maximum likelihood estimates of the model parameters.Finally,taking a certain wire spring-type electrical connector as an example,determine the probability distribution of the contact design parameters based on the "3?" principle,use Monte Carlo simulation analysis to obtain the contact resistance distribution of the contact after storage for a prescribed years,and according to the contact reliability design model of the wire spring-type electrical connector,its contact reliability after 30 years in storage environment is calculated to be 0.99995.The verification of the contact reliability design model of the wire spring-type electrical connector is completed:The residual analysis method is used to prove that the contact performance trajectory degradation model can better describe the degradation of the contact performance of the electrical connector.Using the Aderson-Darling test method proves that the degradation rate of the film layer and the contact resistance obey the lognormal distribution.The method of variance analysis proves that the electrical connector acceleration equation can better describe the linear relationship between the degradation feature quantity and the acceleration stress.