Tyre/rail contact: An experimental investigation on contaminated contact cases

This article investigates how surface texture affects the coefficient of friction (CoF) in tire-rail contact under contaminated conditions. A pin-on-disc test was used to evaluate four steel samples with distinct textures across three contamination protocols: single wetting, periodic wetting, and grease with periodic wetting. Results indicate that under single wetting, CoF values for grooved and shot-peened samples were similar, with the highest CoF in shot-peened samples. Periodic wetting showed minimal CoF variance, while grease with periodic wetting led to the highest CoF in samples ES5 (grooved and counter grooved) and ES3 (grooved/shot peened). Findings suggest that texture height significantly affects CoF oscillations, with parameters like peak and valley density playing a more crucial role than grooves alone under certain conditions.