Conference_programme: 16.2 - Rail Traffic Noise and Vibration: modelling and measurement
Lecture: A advanced measurement technique for an appropriate determination of TDR at less maintained railway tracks
Author(s): Venghaus Helmut
Summary:
The EN 15461 specifies a method for characterizing the dynamic behaviour of the structure of a track relative to its contribution to the sound radiation associated with the rolling noise. Although this method is originally meant for evaluating the performance of sections of reference tracks for measuring railway vehicle noise within the framework of official approval tests, today this method and the calculated TDR is often used for highlighting the differences of the overall noise radiation caused by different track superstructure. \nReference tracks are commonly well maintained, hence major changes of the vertical or lateral impedance of the rail head along a defined track section is not to be expected. Rails in main routes will be machined by a minor maintenance quality. This is often observed by a rapid and remarkable change of the rail head impedance along the track, a negative effect, which causes unwanted deviation by calculating the TDR.\nAn advanced measurement method will be presented based on the method described in EN 15461 to overcome existing problems for determining TDR at poor maintained tracks by use of an additional vibration sensor. An accompanying modification of the EN 15461 is procured by moving the vibration sensors along the railhead instead of the hammer. The driving position of the instrumented hammer is kept steady at the center position of the layout and the two vibrations sensors are moving away from the center position in opposite directions. Doing so, the TDR will be computable for both directions within one layout.\nThe presentation will point out the vibrational differences of railway tracks under well or poor maintaince. The uncertainty in calculating the correspondent TDR will be depicted and the improvement of the accuracy in calculating the TDR data will be presented.\n
Corresponding author
Name: Mr Helmut Venghaus
e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
Country: Germany
