A Study of Degradation Phenomenon of Electrical Contacts by Hammering Oscillating Mechanism: Data and Modeling

A mechanism which contributes oscillation toward electrical contacts by hammering oscillation mechanism (HOM) in the vertical direction has been developed and the influences of a micro-oscillation on contact resistance have been studied. It was suggested that the mechanism could make a study of actual degradation phenomenon on contacts by the influences of a micro-oscillation. First, a mathematical approach in the mechanism of hammering and oscillation using plate dynamic theory in time and space was carried out using continuous approximation by linearly combinations of some functions and unit step functions as external force in time and space field. According to the approach, dynamical characteristics of the mechanism were analyzed by constructing a model of a thin plate with some initial conditions, boundary conditions and transformation of wave functions. By comparing the modeling analysis with experimental results, it was shown that the analysis could express, to some extent, the actual oscillation on a thin board. Second, another mechanical model in the interface on electrical contacts was carried out by considering Coulomb´s friction force and inertial force analyzed by the former model. By comparing the modeling method with experimental degradation data, it was suggested that the method could explain, to some extent, the degradation phenomenon of electrical contacts. By the models it was suggested that the dynamical characteristics of the mechanism, such as displacement, acceleration and mechanical energy, could be derived from linear combinations of basal functions. And by the methods it was thought, to some extent, that a source of the fluctuation of contact resistance caused by the hammering oscillating could be analyzed.