THEORETICAL OPTIMIZATION OF TRACK COMPONENTS TO REDUCE ROLLING NOISE

✍ Scribed by N. Vincent; P. Bouvet; D.J. Thompson; P.E. Gautier

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 361 KB
• Volume: 193
• Category: Article
• ISSN: 0022-460X
• DOI: 10.1006/jsvi.1996.0255

✦ Synopsis

The control of railway rolling noise requires a reduction in wheel and track noise emission. In this paper, a parametric study of the possible minimization of the track sound power is presented. In an initial global approach, a number of potential variations in track parameters are assessed in terms of their likely effect on rolling noise. From this, two main themes are selected for deeper study by use of TWINS model. The first parameter considered is the stiffness and damping of the rail-pad. By reducing the pad stiffness, the noise radiation from the sleeper is reduced but that from the rail is increased, and vice versa. An optimum is found when the rail and sleeper components are equal, for which the track radiation is a minimum. Starting from one existing track design, this optimum pad stiffness has been derived for an example wheel. The second area investigated is the increase of the attenuation rate of rail vibrations by the addition of damping measures. The implementation of dynamic absorbers with a mass of 5 kg every sleeper bay (0•6 m) leads to predicted reductions of track radiation of 2 dB(A) if the rail-pad stiffness is already optimal. For softer pads a larger reduction has been found, but the total effect is less than the combined effect of first changing to the optimum pad stiffness and then adding absorbers. Globally, for ballasted track with bibloc concrete sleepers, a 2-6 dB(A) reduction in track sound power can be expected through a rail-pad optimization and/or the implementation of dynamic absorbers on the rail.