Can One Exclude Track and Rolling Stock Stiffness for the Assessment of Dynamic Impact Forces Due to Variations in Track Profile?

Abstract

The geometric quality of a railway track is an important indicator of track performance and ride quality. European Norms (EN) recommends intervals of geometric values for the plan and profile geometries of railways, and AREMA has recommendations for geometric maintenance. Nevertheless, these recommendations frequently exclude an explicit understanding for the track stiffness and the primary and secondary stiffness values of the rolling stock. However, the authors suggest that track and rolling stock stiffness values affect the dynamic impact forces that develop on railway tracks. Therefore, it is the authors’ opinion that the recommendations for the limits of variability of the track vertical profile must include recommendations for the track and rolling stock stiffness. An analytical method introduced by the authors can explicitly assess the effect of track and rolling stock stiffness on the dynamic impact forces that develop due to variations in track profile, track and rolling stiffness and wheel roughness. This paper will evaluate the AREMA and EN recommendations for the track profile variations. The paper will then introduce the developed method and the analytical equations developed by the method and use these equations with the track profile variation intervals recommended in the EN to show the necessity of specifying track and rolling stock stiffness value intervals along with the recommendations for interventions due to profile variations to reduce train speeds or correct the track profile.