Numerical Evaluation of Sound Attenuation Provided by Periodic Structures

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Authors

  • Mario MARTINS I.P.C., Instituto Superior de Engenharia de Coimbra; CIEC — Departamento de Engenharia Civil da Universidade de Coimbra
  • Luis GODINHO CICC, Departamento de Engenharia Civil, Universidade de Coimbra
  • Luis PICADO-SANTOS DECivil, Instituto Superior Tecnico, Universidade T´ecnica de Lisboa

Abstract

The use of periodic structures as noise abatement devices has already been the object of considerable research seeking to understand its efficiency and see to what extent they can provide a functional solu- tion in mitigating noise from different sources. The specific case of sonic crystals consisting of different materials has received special attention in studying the influence of different variables on its acoustic performance. The present work seeks to contribute to a better understanding of the behavior of these structures by implementing an approach based on the numerical method of fundamental solutions (MFS) to model the acoustic behavior of two-dimensional sonic crystals. The MFS formulation proposed here is used to evaluate the performance of crystals composed of circular elements, studying the effect of varying dimen- sions and spacing of the crystal elements as well as their acoustic absorption in the sound attenuation provided by the global structure, in what concerns typical traffic noise sources, and establishing some broad indications for the use of those structures.

Keywords:

traffic noise, sonic crystals, numerical methods.