%0 Journal Article
%T Estimation of track parameters and wheel每rail combined roughness from rail vibration
%A David J Thompson
%A Martin GR Toward
%A Qi Li
%J Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit
%@ 2041-3017
%D 2018
%R 10.1177/0954409717710126
%X Rolling noise from running trains is significantly influenced by the wheel每rail combined roughness and the dynamic properties of the track. To facilitate predictions of vibration and noise, it is desirable to be able to determine these parameters accurately from field measurements. In this study, an inverse method for the determination of these parameters is adopted and enhanced. A track model that is based on a wavenumber finite element model of the free rail coupled to discrete supports, which allows for the pinned每pinned mode and cross每sectional deformation of the rail, has been used. The rail vibration induced by hammer impacts and the vibration during train passages are simulated using this model, and these results are then applied to illustrate the accuracy of the direct and indirect methods for the estimation of track decay rate. These methods are compared in a case study for a ballasted track for which hammer impact and train pass每by measurements have been obtained. Other track parameters can also be extracted from the measured data by using the advanced track model. Thereafter, a more complete method is adopted to estimate the wheel每rail combined roughness from the measured rail vibration under train passages. A comparison is made among the estimated roughness levels obtained from this full method, an existing simplified method and the direct measurement method. It is found that the simplified method overestimates the roughness around the pinned每pinned resonance frequency, but gives a good estimation if the track decay rates of the loaded track are used
%K Ballasted track
%K wheel每rail interaction
%K track decay rate
%K roughness
%K parameter estimation
%U https://journals.sagepub.com/doi/full/10.1177/0954409717710126