Vibro-Acoustic analysis of urethane foam using X-ray CT data

Abstract

Polyurethane foam for sound absorption is used to reduce noise in automobiles, houses, home appliances, etc. The Biot-Allard model is generally used to calculate the sound absorption characteristics of urethane foam, which is used as a sound absorbing and insulating material for automobiles. Biot parameters used in calculations are measured with a dedicated measuring instrument, but it is difficult to connect them to actual material development. In order to clarify the sound absorption mechanism, 3D data of the urethane skeleton was obtained using an X-ray CT device. The FE model of the skeleton and surrounding air was created from the 3D data of the skeleton, and vibro-acoustic analysis was performed. We report the results of comparison between the results of normal incidence sound absorption coefficient measurement using acoustic tubes and the calculation results of the FE model, and the results of various parameter studies. And, we also report the calculation results of urethane foam laminated with films.