An Evaluation Method for Electrical Contact Failure Based on High-Frequency Impedance Model

As a major component of electrical wiring interconnection systems (EWISs), aircraft electrical connectors are used for the transmission of electrical signals and electrical connection between electrical equipments. It is known that electrical contact failure is the primary failure mode of connectors. Contact resistance often presents a transient characteristic that is difficult to reflect the degradation comprehensively. The electrical contact failure mechanism of connectors is studied in this article. In order to evaluate and quantify the electrical contact failure state, a high-frequency contact impedance model is established to represent the relationship between microphysical characteristics and electrical parameters. Furthermore, the influence of surface roughness and corrosion degree on the high-frequency contact impedance model is investigated by finite-element simulation and accelerated degradation experiment. The trends of contact impedance at high frequency are compared with that of contact resistance at dc condition under the circumstances of different degradation degrees. Finally, the variation law of contact impedance at high frequency is revealed, which can provide the theoretical basis for performance degradation assessment, service life prediction, and reliability evaluation for electrical connectors.