Effect of liquid high positive friction (HPF) modifier on wheel-rail contact and rail corrugation

This paper presents an experimental study on the influence of HPF friction modifier on rail corrugation. The tests were carried out on a curve section of a commuter line, where corrugation appeared in the inner rail of the curves. The influence of HPF on wheel-rail contact forces has been studied based on acceleration measurements on the rail. These measurements were carried out with and without corrugation on the rail. in order to compare the corrugation levels developed with and without the HPF, the evolution of corrugation was analyzed for this particular curve. The corrugation amplitudes and wavelengths were studied. It was found that the application of HPF substantially reduces the acceleration levels on the rail in vertical and lateral directions and delays the corrugation growth.