Proceedings of the 10th Convention of the
European Acoustics Association
Forum Acusticum 2023


Politecnico di Torino
Torino, Italy
September 11 - 15, 2023





Session: A17-05: Railway noise detection, monitoring and abatement
Date: Wednesday 13 September 2023
Time: 17:00 - 17:20
Title: Acoustical optimization of railpads by F.E. Modelling and validation by measurements
Author(s): E. Verhelst, SD&M (Structural Dynamics and Monitoring), Impasse La Borderie,1, 87120 Domps, France
E. Balmes, SDTools, Rue Vergniaud, 75013 Paris, France
Pages: 3301-3307
DOI: https://www.doi.org/10.61782/fa.2023.0784
PDF: https://dael.euracoustics.org/confs/fa2023/data/articles/000784.pdf
Conference proceedings
Abstract

Noise emission is often influenced by resonances. In case of wheel-rail contact during train pass-by the rail is excited at his resonance frequencies, e.g., the pinnend-pinnend resonance. The only component in contact with the rail that can damp this resonance is the rail pad. It is known that, when changing railpad dynamic properties as stiffness and damping, the pass-by emission can be reduced significantly. In several projects in Europe, it is shown that railpad optimization in terms of stiffness and damping results in noise reduction of more than 3 dB compared to standard soft pad, for passenger and freight trains at speeds between 80 and 160kph. The goal of this study is to further optimize the rail pad design, to keep the flexibility in the track for protection of sleepers and ballast, combined with a high TDR, or rail vibrational damping. The focus lies on the optimization of the stiffness distribution over the railpad surface. It is shown that, for the same global vertical railpad stiffness, the TDR can be optimized in the pinnend-pinnend area. The optimization is first done in a frequency dependent F.E.M., then optimized railpads are mounted in a track and noise emission is compared with non-surface optimized railpads.