Computing the sound radiation of railway tracks in 2.5D using FE commercial codes: application to tram tracks
Résumé
This paper is part of research aimed at reducing noise emissions from railway infrastructures, especially rolling noise. The track itself emits an important part of the rolling noise and the modeling of its vibro-acoustic behavior is necessary to estimate its contribution.
In a first approach, the track can be considered as an infinite and invariant structure in the longitudinal direction. For the calculation of its vibratory behavior, wave-guide methods, like the Semi-Analytical Finite Element method or the Wave-guide Finite Element Method, are therefore naturally adapted. It couples a wave description in the longitudinal direction and a finite element discretization of the cross section.
Concerning the sound radiation, a 2.5D approach, based on the wave decomposition of the exciting vibratory field is well adapted. The fluid medium being open, the use of boundary elements methods is most often used. However, the implementation boundary elements in 2.5D generally requires the development of dedicated codes.
Alternatives exist such as infinite acoustic elements or Perfectly Match Layers which are more often implemented in commercial software. In this paper, it is shown how the sound radiation of railway tracks can be determined by combining 2D acoustic calculations and wave superposition. An application to tram tracks is proposed.
Domaines
Sciences de l'ingénieur [physics]
Origine : Fichiers produits par l'(les) auteur(s)