The design goal of many automotive programs is to provide as much absorption in the interior of the vehicle as possible. Automotive seats generally play the most significant role in the sound absorption of the vehicle interior. An earlier study looked at the performance of various seat configurations from an experimental point of view. While that study was useful, it was felt that an analytical model of the seat was needed to understand and optimize its acoustic performance. A model has been developed that assumes the seat consists of a surface layer (fabric or leather), a thin slab foam layer, and a thick cast foam cushion. For a given seat shape, the sound absorbing characteristics depend on the acoustical/mechanical parameters of these layers. Optimizing the parameters of these layers as a system is critical in improving the sound absorption of seats with low cost and weight. For this paper the normal incidence absorption of various seat material configurations is shown. Random incidence data will be shown in a later paper. These predictions are compared to impedance tube measurements and the agreement is quite good. The effect of a number of paramters of seat cover materials and cushions are considered and some optimized results are shown. The density, porosity, airflow resistance, and thickness of each layer were actually measured and used as input data to the model. The shear modulus, Poisson's ratio, and tortuosity were estimated. For the covering abstract see IRRD E104312.


  • English

Media Info

  • Features: References;
  • Pagination: p. 601-6

Subject/Index Terms

Filing Info

  • Accession Number: 00790204
  • Record Type: Publication
  • Source Agency: Transport Research Laboratory
  • ISBN: 0-9622072-3-3
  • Files: ITRD
  • Created Date: Apr 11 2000 12:00AM