Rapid optimization and design of mag-based composite dash panel with SEA method

The dash panel SEA model containing 27 subsystems was established and the basic SEA parameters were determined by theoretical calculation. Comparison between the calculated transmission loss(TL)and the test results showed that they fit well, which proved that the SEA method was feasible to calculate TL of mag-based dash panel in high frequency range. According to the sound transmission curve of the various subsystems, it was necessary to make acoustic optimization on the whole rather than part of the model of the dash panel in high frequency range. A composite dash panel was thus designed. For a more objective evaluation of its optimization effect, noise reduction efficiency was proposed to be used as a comprehensive evaluation index on dash panel sound package. With consideration of the noise reduction efficiency, the limit of the interior space, lightweight and cost requirements, the optimal thickness of the air layer is determined to be 1 mm and that of the porous sound-absorbing layer is 10 mm, after the thicknesses of the two layers have been changed several times. The TL increases by 20.2 dB on average after acoustic optimization, which is very significant in engineering application. ©, 2015, Tianjin University. All right reserved.