ABSTRACT
The wheel/rail contact is a crucial component in the successful operation of railways. A large variety of loading conditions and contact geometries exist due to the many different rail and wheel profiles, rail cant and curve radii, and railway vehicles running on a network. Contact conditions vary considerably between the two main contact areas: wheel tread/railhead and wheel flange/rail gauge corner, but are usually more severe in the latter, where greater wear and fatigue cracking is seen to occur. Friction and creepage in the contact are also highly variable. Natural lubricants such as humidity, precipitation, and leaves can negatively influence the friction in the wheel/rail contact, causing braking problems and wheel slip in traction. These problems can be overcome by using applied lubricants to reduce wear in curves and friction modifiers to increase adhesion. This, however, further adds to the complexity of the wheel/rail contact system.
