A Study on Sound Generating Mechanism Using Vibrational Energy and Sound Energy. 1st Report. Effects of Dissipation Energy on Vibrational and Sound Energy Flow.

Abstract

Most of the sound radiated from vibrating structures is structure-borne sound. The purpose of this paper is to study the generating mechanism of the structure-borne sound. The analytical model is a rectangular plate, which is a basic element of structures. The plate is excited sinusoidally at one point. Damping is taken into consideration by using a proportionally damped model or a dashpot model. The dynamic response of the plate is calculated using the finite element method to obtain vibrational energy and sound energy. As a result, the vibrational and sound energy flow patterns, which are expressed by vector quantities of structural and sound intensities, are compared. The effects of the vibrational dissipation energy on the flow patterns of the sound energy are also investigated and two types of flow patterns (S and M types) are found.