On Acoustic and Vibroacoustic Characteristics of Multilayer Composite Panels

Abstract

The results of experimental studies on determining the acoustic and vibroacoustic characteristics of multilayer composite panels are presented. Four flat 3-20-mm-thick panels made of 5, 9, 12, and 34 layers of a polymer composite material (PCM) are tested in the opening between reverberation chambers. The values of the transmission loss and acoustic vibroexcitability are determined for panels excited by a diffuse sound field. The radiation loss factors into the high- and low-level chambers and the total loss factors are determined for panels excited by a vibration exciter with an impedance head mounted on it. The values of the modal density of the panels are estimated. The results are obtained in one-third octave bands in the range of 100–8000 Hz. It is shown that the acoustic and vibroacoustic characteristics of the panels have a universal character. Simple empirical relations are derived for describing these characteristics. The measured vibroacoustic characteristics of the panels made of a PCM are compared to those of a traditional stiffened fuselage panel.