Vibro-acoustic analysis of the sound transmission through aerospace composite structures

Abstract

An in-plane honeycomb sandwich structure used in aerospace applications has been modeled, in order to study the structural-acoustic performances of the sandwich panel using a finite element analysis software. A modal and steady state analysis were conducted to investigate the vibro-acoustic and sound transmission characteristics of the sandwich panel. Several materials used in aerospace composite structures were tested to compare their acoustic performances and to deduce which material have a good acoustic insulation property. Two different cases of structural acoustic design, were performed in this research taking into account the effect of changing material, thickness of skins and the total mass on the sound transmission characteristics of the sandwich panel through varying the effective properties without compromising the mass of the panel in case of the first design. In case of the second design, we consider the thickness of skins as constant. The results reveals that the glass fiber reinforced polymer (GFRP) cores with fiber-reinforced plastic (FRP) facing materials have a better vibro-acoustic and sound transmission characteristics comparing to all other design cases presented in this article. GFRP cores with an FRP facing can replace the aluminum materials without affecting the acoustic performances of the panel with a mass reduction of the panel.