Impact oscillations with multiple modes between a pantograph and an overhead rigid conductor line in a railway current collection system

A theoretical and experimental investigation was conducted into impact oscillations between a pantograph and an overhead rigid conductor line in a railway current system. The contact problem was modeled as impact oscillations of an intermediate spring-supported beam excited by an oscillating plate. First, the impact oscillations of a beam with a sinusoidal vibrating plate were theoretically examined. The impact relations are derived considering the effects of multiple vibration modes. Using some of the concepts behind periodic oscillations, qualitatively distinct impact oscillations of the beam with multiple modes are clarified. The interactions between the lowest two modes during the impacts are also discussed. Moreover, we conducted an experiment using a similar model based on the analytical model. Qualitative agreement was demonstrated between the experimental and theoretical results. Some experimental results reveal specific impact oscillations which correspond to the theoretical results considering the interactions between the lowest two vibration modes.