Research On The Mechanism Of Electrical Connector Loosening Failure Under Multi-axis Random Vibration

Electrical connectors are widely used in devices,components and systems for signal transmission and electrical connection.They are necessary basic components to form a complete electrical system.They are used in military and civilian systems such as aerospace,electronic appliances,industrial automation,machine vision applications,and rail transit applications.For such weak current connection failures or electrical connection reliability problems whose main function is to transmit signals,the vibration environment is one of the main influencing factors.Scholars at home and abroad have done more research on the failure of electrical connectors under vibration conditions,such as fretting wear,material creep,contact stress relaxation,etc.,in experimental and theoretical aspects,and have made certain progress.But for electrical connectors under vibration conditions,there are few studies on the loosening of connectors,especially when the fastening bolts at both ends of the electrical connector fail,the research on the connection failure process of the electrical connector structure itself is relatively rare.Therefore,in order to improve the reliability of electrical connector connections in actual projects,this article explores the mechanism of electrical connector loosening failure by simulating the change history of structural dynamic response characteristics during the loosening of the connector.Combining random vibration theory,finite element method and electrical contact theory organically,the electromechanical characteristics of electrical connectors are explored on the electronic cabin under random vibration environment.The main work of this paper can be summarized as follows:(1)The finite element analysis method of electrical connectors is studied.The contact pressure inside the contact is extracted and compared with the theoretical calculation value,which verifies the effectiveness and feasibility of the finite element simulation method for electrical connectors,and provides relevant technology for the subsequent analysis of the loosening of electrical connectors in the cabin.(2)The differences in the response of electrical connectors on the cabin section under single-axis and three-axis random vibration environments are compared.A model of the electrical connector on the missile’s electronic module is established.By comparing the difference in structural response between the three-axis and single-axis random vibration environments,the quantitative relationship between the three-axis vibration and the single-axis vibration of the electrical connector simulation results is compared,and it is found that the acceleration and stress response on the cabin section electrical connector under the three-axis vibration environment are larger than those under the single-axis vibration environment,and the response peaks under the three-axis excitation are more numerous and include the single-axis response peaks,proveding the necessity of the research on the loosening of electrical connectors under multi-axis random vibration.(3)The stress evolution mechanism of the electrical connector loosening process under random vibration is obtained.The loosening process of J30J-31 pin micro-rectangular typical aviation electrical connector under random vibration environment is simulated,and the dynamic response change course of the structure during the loosening of the electrical connector is obtained.It is found that the loosening process can be divided into three stages:stable zone,transition zone and loose zone.Two different random vibration environments of both single-axis excitation and three-axis excitation are set up to analyze the loosening process of the electrical connector,and compare the structural dynamic response characteristics of the electrical connector in the three-axis random vibration environment and the single-axis random vibration environment.It summarizes the similarity in trend and the difference in interval between the two loosening process curves under the two vibration environments.(4)Since the contact pressure on the inner wall of the electrical connector is difficult to measure,and the contact resistance measurement of the electrical connector is relatively simple.If the stress-resistance mapping relationship during the loosening process of the electrical connector is obtained,it can be judged whether the electrical connector is loosened according to the change of the contact resistance value.Finally,the resistance measurement experiment of the electrical connector loosening process is completed,and the simulation results are compared with the experimental data to verify the correctness of the simulation results.This method provides a simple technical means for monitoring the loosening of electrical connectors through resistance measurement.