Analysis of Current Distribution on Armature and Rail Interface With Dynamic Contact

The armature and rail (A/R) interface is a dynamic imperfect electrical contact (ImPEC), involving varying contact pressure and areas. In this article, the contact pressure and current distributions on the dynamic convex A/R interface are studied with boundary conditions for dynamic ImPEC. The numerical results indicate that the contact pressure has a central distribution pattern, and the contact area variation trend is similar to the driving current. Current distributions on the dynamic A/R interface with different motion states are different. On the stationary interface, the current concentrates on the trailing edge at the beginning, diffuses to the leading edge during the flat stage, and concentrates on the leading edge as the contact area contracts with the decreasing driving current. However, the current concentrates on the trailing and side edges of the sliding interface throughout the whole stages under low-velocity conditions. Comparative calculations have been conducted to investigate current evolution patterns on dynamic contacts. Results suggest that both stationary and sliding interfaces exhibit significant current fluctuations on contact area boundaries, which are concluded as forced shifts of current caused by dynamic contacts.