High-frequency vertical wheel-rail contact forces-Field measurements and influence of track irregularities

Field measurements of vertical wheel-rail contact forces in the frequency range 0-2000 Hz are reported. Instrumented wheels are employed together with a new method for signal processing including suppression of disturbing wheel resonances. Four different classes of rail irregularities are identified which all require consideration of high-frequency dynamics when evaluating wheel-rail contact forces. Ten stretches of Swedish track were selected for inspection and measurement of rail irregularities. The expected correlation between rail corrugation and measured dynamic forces is confirmed. It is found that high-frequency dynamics in the range 100-1250 Hz contributes significantly to contact forces which are important in the development of rolling contact fatigue. The present application is to high-speed trains on the Swedish track network with its mixed passenger and freight traffic. However, the method makes it possible to assess the level of high-frequency wheel-rail contact forces for all types of train traffic and could be used for a quantitative analysis of a complete railway network.