Estimation of coefficient of friction between flange and rail utilizing vehicle dynamics simulation (Investigation based on roller-rig test with different lubrication condition)

Abstract

The coefficient of friction (COF) between the outer rail and the leading-outside wheel flange of a railway bogie running on sharp curved track is an important parameter for the progress of wheel/rail wear and running safety. Therefore, it is desired to grasp the actual state of COF of wheels especially at the leading-outside wheel flange. In the author’s previous studies, a roller-rig experiment was conducted with changing lubrication condition of each wheel of the bogie to figure out relationship between lubrication conditions and wheel/rail contact forces such as tangential, lateral and vertical directions. In this paper, a method to estimate the value of COF of leading-outside wheel with look-up tables built by repetitive numerical simulations is explained. In the construction of the look-up tables, friction coefficients for each wheel in the numerical simulation model are changed while collecting calculated wheel/rail contact forces. A railway bogie running on roller-rig test is considered for both numerical simulations and experiment with different lubrication condition, therefore look-up tables are built with a half-vehicle model running on the roller-rig. By inputting the wheel/rail contact forces measured in roller-rig test into the look-up tables built by simulations, and the COF of leading-outside wheel flange is estimated. The result shows that the lubrication condition of leading-outside wheel flange can be estimated by the proposed method especially when the value of COF is large and is useful for the detection of high COF condition.

Keywords

• railway
• multibody dynamics simulation
• roller-rig test
• estimation
• coefficient of friction