123 Analysis of vibro-acoustic behavior of micro-perforated thin aluminum plate for sound absorber : Reduction of natural vibrations and improvement of sound absorption performance

Abstract

As a new sound absorption material, micro-perforated aluminum thin plate has been developed to solve some problems of fibrous sound absorption materials. But its stiffness is not so large, so it is vibrated easily by sound pressure. And sound absorption performance is affected by its vibration to decrease the coefficient of sound absorption. This paper describes the relationship between the vibration behavior of micro-perforated thin aluminum plate excited by sound pressure and the sound absorption performance of that plate. The vibro-acoustic behavior was observed by using the laser scanning vibrometer, and the sound absorption coefficient was measured by two microphones method.