Storage Reliability Evaluation Of Spring For Separation Electrical Connector

As a kind of storage equipment,the separation electrical connector is mainly used to transfer and cut off the electric energy and electrical signal in the system,which is widely used in aerospace and other military systems.Spring,as a kind of elastic energy storage part,mainly realizes the function of separating and unlocking the electrical connector.However,the degradation of spring performance under storage conditions will lead to separation failure of electrical connectors.Therefore,the reliability evaluation of spring storage is very important for electrical connectors.In this paper,the reliability evaluation of the spring for the electric connector is completed from four levels: theoretical research,mechanism modeling,test design and model mechanism verification.It will provide a systematic and scientific method for the reliability evaluation of the elastic parts of related storage models.The contents of the study include the following aspects:First,from the separation of the structure and function of the electrical connector,the most easily failed spring in the electrical connector is determined to be the head seat separation and collision sleeve two types of helical spring.Combined with the mechanical analysis of springs,the critical failure equations of two kinds of springs are given.At the same time,the environmental effects of helical springs used in electric connectors are analyzed and the storage failure mechanism of helical springs is revealed to be dislocation slip and stress relaxation caused by dislocation plugging.Second,based on the dislocation slip theory of crystals,considering the internal mechanism of the influence of dislocation packing on the stress relaxation of crystals in the spring under storage condition,the variation law of plastic strain rate with time was deduced,and the trajectory model of spring elasticity degradation under storage condition was established.Based on the relaxation and degradation rule of spring elasticity under temperature stress and the Arrhenius equation,the reliability statistical model of spring acceleration degradation equation under storage state was established.Third,the bottom test is carried out for the head seat separation spring and the bump sleeve spring of a certain torque type separation and fall off electric connector,and the basic characteristics of spring performance degradation are determined.The spring acceleration degradation tests at 105℃,120℃,140℃ and 158℃ were designed and carried out.The results show that the performance degradation of spring is affected by temperature and initial compression force.Then the least square method and maximum likelihood estimation are used to determine the parameters of the spring performance degradation model.Finally,Monte Carlo simulation was used to evaluate the storage reliability of the spring.Finally,the consistency of failure mechanism and degradation model of spring are tested.It is proved that the spring performance degradation model based on dislocation plug product is superior to other models.Finally,by means of metallographic microscope and transmission electron microscope,the microstructure of spring is analyzed,and the failure mechanism of spring for storage electric connector is further clarified.