Sound absorption structure optimization based on material absorption models and noise rating curves

The sound absorption materials are more and more widely used in vehicles. An novel optimal design method is proposed in this paper, which mainly includes two steps: (i) the determination of expected absorbing curve based on noise reduction goal and noise rating curve; (ii) choice of absorption materials and optimization of the material thickness based on the sound absorption model. The method has been applied to the absorption performance improvement of some vehicle´s engine cabin and the results prove to be satisfactory. The absorption coefficients have been improved by 0.2 in the frequency range of 0-1200Hz.