Time and Level Analysis of Contact Voltage Intermittences Induced by Fretting in Power Connector

It is well known that vibrations of contact interfaces are the main cause of contact degradation by the so called fretting corrosion phenomena. In fact the process of generated particles by mechanical wear produce either the increase of contact voltage accompanied with rapid fluctuations. The main objective of this work is to examine the electrical behaviour of contact interface under vibration and characterize theses fluctuations during the fretting. A single point contact is submitted to high number of vibrations (103 to 107) at 100 Hz with an amplitude of 50 mum. The contact is in a resistive circuit supplied by 14 V and 10 A. The contact voltage is acquired with fast sampling oscilloscope and fluctuations are analysed by real time FFT module. We have found that, depending on the degradation stage, the apparition of these fluctuations is attributed to electro-mechanical phenomena. Some slow fluctuations are well correlated to vibration period while the rapid ones are linked to electrical conduction perturbation in granular interface by movement. Furthermore, the self-heating by such high contact voltage at high current levels is examined.