EVALUATION OF ACOUSTIC PROPERTIES OF COMPOSITE MATERIALS WITH POTENTIAL APPLICATION IN THE SOUND BARRIERS STRUCTURES

Abstract

The European strategy requires harmonization of various methods to reduce noise with actions on the noise sources, on the receptor and on the sound propagation medium. Regarding the reduction of noise level using insulating structures, one of the issues of research is based on study of acoustical properties of materials and optimum geometry of sound barriers. The paper aims to present one of the modern and non-destructive method to determine the natural frequencies and damping coefficient of plates made from different materials: plywood, composite (epoxy /glass fibre mixed with various form of reinforcement pattern). Based on Rayleigh-Ritz method and the vibration tests of the freely supported composite plates, natural frequencies were predicted.