ABSTRACT
The key area of any study of railway vehicle behaviour is the contact between the wheels and the rails. All the forces that support and guide the vehicle pass through this small contact patch, and an understanding of the nature of these forces is vital to any analysis of general railway vehicle behaviour. The equations that govern these forces are derived and explained by Hugues Chollet, Jean-Bernard Ayasse and Michel Sebès in this chapter. They include an analysis of the normal contact that governs the size and shape of the contact patch and the stresses in the wheel and rail and also the tangential problem where slippage or creep in the contact patch produces the creep forces, which accelerate, brake and guide the vehicle. This chapter is also intended to provide railway engineers with an overview of the way wheel-rail contact forces may be assessed inside railways dynamics software, where numerical methods have to be effective enough to be used extensively.
