Experimental Study Of Electrical Contact Characteristics For Aviation Electrical Connector Under Combined Environmental Stress

High temperature and vibration environment stress are the main reasons for the failure of aero-engineelectrical connectors.Electrical connectorsas part of aero-engine are considered as the object of the study. Aero-engine electrical connector electrical characteristics experiment system under combined environments has been developed, loading temperature environment stress and vibration environment stress at the same time, real-time monitoring of electrical connector contact resistance, so as to investigate the influenceofcombined environment stress on the aero-engine electrical connector electrical contact performancesuch as variousvibration frequency, amplitude, acceleration, current, environment temperature.Structural dynamics model and finite element model, combined with electrical contact basic theory, determinethe failure mechanism of electric connector contact resistance fluctuations.Firstly, mechanical fixtures connecting electrical connector and electromagnetic vibration equipment have been designed, and the vibration environment stress experimental conditions have been determined; temperature-controllingequipmenthas been designed, loading high environmental temperature stress; four-wire-methodcircuit has been designed, real-timely acquiring contact resistance data; PC software collecting, displaying, storing and processingthe contact resistance has been written. so the work of the electrical connector electrical contact characteristics test system has been finished, controlling and loading the vibration, temperature and current stress experimental parameters.Then, the influence of the vibration environment stress on the contact resistance of the electrical connector has been studied experimentally.The variation of contact resistance under different frequency and amplitude has been studied, and the influence of electrical connector installation mode on the fluctuation of contact resistance is studied.. Identified electric connector vibration displacement transfer path, established the structural dynamics model of the electric connector, get the relationship between the experimental phenomena and theoretical model, more deeply understand the vibration environment stress of electrical connector contact resistance fluctuations were investigated.Secondly, the influence of environmental temperature stress and current stress on the contact resistance of electrical connector has been studied. A detailed study of general rules of the environmental temperature rise, contact resistance and temperature rise of electric connector has been investigated. Combined with the finite element model,it has been determined that the environmental temperature rise increases the electrical contact materials resistivity, influencing the electrical connector mostly. The general laws among the current stress, contact resistanceand temperature rise of electric connector has be obtained, and the current rises the temperature and softensthe coating, which is the main reason for contact resistance changing with temperature rising.Finally, the influence of temperature and vibration environment stress on the contact resistance of electrical connectors has been studied. Acquired by experiment, the most intense fluctuation of contact resistance happens at 100℃, and the vibration environment stress can reduce the of roughness coefficient of contact surface. The main factors that affect the electrical contact characteristics of the electrical connector has been summarized, and the action law and the influence degree of these factors has been analyzed.Results of this paper can be directly applied inthe reliability test and analysis process of aero-engine electric connector, wire and cable, resulting significanteconomic value.