Overview of Wheel-rail Rolling Contact Theories

Abstract

In the contact area between wheel and rail there are intensive action and reaction forces that have a key influence on the dynamic behavior of railway vehicles and track. These forces play a key role in supporting, guiding, traction and braking of railway vehicles. Bearing in mind that the wheel-rail contact problem is in fact the problem of rolling of two nonlinear profiles which occurs under the influence of many parameters, its solution and exact determination of wheel-rail contact forces belongs to the most complex tasks in railway engineering. Basically, solving the wheel-rail contact problem is reduced on solution of two types of contact problems - normal and tangential. These mutually coupled problems are solved from many researchers and today there are several different theories. Simpler theories are based on the assumptions under which the normal and tangential contact problem are solved completely separately. This results in a significantly simpler and faster calculation, but with greater error. On the other hand, more complex theories are based on coupled or iterative solving of given problems. As a result, they are characterized by greater accuracy, but also with more complicated calculation that requires significantly more computing time. In that sense, the aim of this paper is to analyze the wheel-rail rolling contact theories for solving the normal and tangential contact problems, with especial emphasize on determination of wheel-rail contact forces. Established conclusions are of particular importance for research of dynamic behavior of railway vehicles.