On the Component of Track Damping Resistance and Related Damping Measurements


This paper present analytical equations for estimating the damping resistance of railway tracks based on the model of a single infinite beam supported by a Kelvin foundation. Considering practical range of speed and track parameters, a simplified formula for estimating the damping resistance was obtained. Using this formula, graphs were presented of the damping resistance versus wheel load and speed for parameters typical of tracks on wood ties and tracks on concrete ties.
Results of an experimental method for determining track damping levels are also presented. The method is based on vibrating the track structure with a vertical harmonic load and measuring the phase shift between the applied load and the resulting vertical rail deflection. Levels of track damping are determined by comparing the measured values of phase shift with the ones obtained from analytical results. The method was applied to three tracks with different tie-fastener arrangements. Results of this test included variations of track damping with the amplitude and the frequency of the applied load.