Study On The Influence Of Temperature And Humidity On The Insulation Performance Of Polyurethane Adhesive For Electrical Connectors

Electrical connector is a basic electronic component for electrical signal transmission and energy transfer,in a variety of weapons and equipment systems are widely used,the reliability of the electrical connector is directly related to the success or failure of the type system tasks.Electrical connector insulation is used for electrical isolation between contact pairs and between contact pairs and the shell,and its performance directly affects the reliability of electrical connectors.At present,research on the reliability of electrical connectors mainly focuses on contact parts,and there is relatively little research on insulation parts.This article takes polyurethane adhesive insulation parts used in electrical connectors as the object,analyzes the storage environmental effects of polyurethane adhesive insulation parts,and determines the main environmental influencing factors that affect their performance.Based on the accelerated test data of polyurethane adhesive insulation parts,the influence of temperature and humidity on the insulation performance of polyurethane adhesive insulation parts is studied.Evaluate the reliable life of polyurethane adhesive insulation components under storage environment(25℃,50%RH),and the specific research content is as follows:Combined with the materials and functions of polyurethane insulation parts for electrical connectors,the effect and failure mechanism of polyurethane insulation parts in storage environment were analyzed.Considering the testability and sensitivity of performance indicators,the insulation resistance was determined as the insulation performance indicator of polyurethane adhesive insulation components.The rationality of the indicator selection was verified through thorough testing.Based on the theory of response surface design,with the aim of quantitatively analyzing the relationship between the insulation performance of polyurethane adhesive and temperature and humidity stress,as well as the effect of temperature and humidity on the insulation performance of polyurethane adhesive,by comparing the advantages and disadvantages of commonly used response surface design methods,the surface center composite method(CCF)is determined as the combination method of temperature and humidity stress levels for electrical connectors.By designing parameters such as sample size,test interval,and test cut-off time,we have developed a temperature and humidity dual stress accelerated test plan for polyurethane adhesive insulation components,and implemented nine stress combinations for accelerated testing.Based on the collected accelerated test data of polyurethane adhesive insulation components,the K-W test method and S-W test method were used to preprocess the accelerated test data,verifying the assumption that all samples follow the same population.The A-D method was used to test the optimal distribution fitting of the degradation amount,and it was determined that the degradation amount of polyurethane insulation parts obeyed the normal distribution.Based on the degradation distribution and the weakest loop model of the system,the insulation reliability function of polyurethane adhesive insulation components is derived.By using the Goodness of fit RZ method,it is determined that the degradation track of the average value μk(t)and the standard deviation σk(t)of the degradation amount of polyurethane insulation parts conforms to the exponential function model.By using the mean and standard deviation of insulation resistance as indicators,and analyzing the effects of temperature and humidity on the mean and standard deviation of insulation resistance,it was determined that there are nonlinear and interactive effects of temperature and humidity on insulation resistance.Through statistical analysis of accelerated test data,the t-test method was used to verify and pass the consistency test of failure mechanisms under nine groups of temperature and humidity accelerated stress levels.Based on the response surface method,a multivariate nonlinear regression accelerated model was established for the mean and standard deviation of polyurethane adhesive insulation resistance as a function of temperature and humidity.By comparing the variance analysis and Pareto index of two accelerated models,it was found that temperature has a greater impact on the degradation rate of polyurethane insulation components than humidity.Humidity is a significant influencing factor that causes different degradation rates of polyurethane insulation components,and there is an interactive effect between temperature and humidity on the degradation rate of polyurethane insulation components.The correctness of the accelerated model was verified by residual graph analysis and Goodness of fit test of RNL value.Combining the insulation reliability function and acceleration model of polyurethane rubber insulators,the storage reliability model of polyurethane rubber insulators was finally developed,and the point estimates of the reliable life of polyurethane rubber insulators under storage environment(25℃,50%RH)were evaluated based on this model,and the 95%confidence interval estimates of each reliable life were given.