Effect of Friction Modifiers on Adhesion in Wheel-Rail Contact

abstract

English

One of the key factors in railway transportation is adhesion since it influences safety and energy efficiency of the traffic. However, the adhesion level is strongly dependent on operating and environmental conditions. Under wet conditions and when leaves are on the track, poor adhesion causes braking and traction difficulties. In this case, sanding is often used to increase adhesion. On the other hand, under dry conditions the adhesion level may be unnecessarily high; this leads to higher wear, vibrations and noise. Therefore top-of-rail friction modifiers have been developed to ensure an appropriate adhesion level. The friction modifiers are substances of complex composition that influences adhesion. The objective of this study is to investigate effect of the friction modifiers composition on the adhesion in the wheel-rail contact under dry and wet conditions. The experiments were carried out using a ball-on-disc tribometer and a twin-disc tribometer under various conditions. Traction forces have been recorded and a corresponding adhesion curves have been evaluated. The results bring further insight into the very up-to-date issue and suggest the effect of particular components of the top-of-rail friction modifiers.

wheel-rail contact, friction modifiers, adhesion and adhesion coefficient

GALAS, R.; OMASTA, M.; KŘUPKA, I.; HARTL, M.

16. 9. 2015

Japanese Society of Tribologists

Tokyo

973

974

2