Threshold of Axial Vibration Induced Fretting in Electrical Connectors

Random and single frequency vibration tests were used to investigate vibration behaviors and thresholds of the fretting corrosion of connector samples with different wiring tie-off lengths. Multiple vibration modes and the rocking style motion of the connector systems were observed. Through experimental threshold tests, the threshold behavior at various frequencies for the onset of fretting degradation was identified. Typically the micrometer-scale axial vibration was able to trigger the fretting corrosion of the connector samples. It is also found that the threshold amplitude at the natural frequency of one of the modes was the lowest. Thresholds at this mode of the connectors with different wiring tie-off lengths were also tested. In addition, a discrete vibration model was developed to explain and predict the threshold behavior. Through a parametric "best fit" of the vibration transfer functions, the thresholds predicted by the model correlated well with the experimental results. The analysis demonstrated that the thresholds are greatly affected by the stiffness and damping as a result of the tie-off configurations. Consequently, it is concluded that the dynamic response of the mechanical system under various tie-off configurations can greatly influence the performance of the vibration induced fretting corrosion of a connector system.