Experimental and Theoretical Study of a Structural-Acoustic Coupling System

Minimization of Sound Pressure Level of Acoustic Tube by Dynamic Vibration Absorber

Abstract

In previous papers, as a basic study for reducing booming noise of a wagon-type vehicle, the authors analyzed the sound field of a rectangular space with flexible panels at some of its surface planes, regarding the space as a structural-acoustic coupling system. As a continuation to previous papers, the authors consider use of a dynamic damper. It is found that dynamic dampers designed following the usual guidance for structures are not satisfactory for the present purpose. So, in this study, optimum designing of a dynamic damper for structural-acoustic coupling systems is examined. For this purpose, first, guidance for optimum designing is proposed based on a one dimensional structural-acoustic coupling system. Then, the effectiveness of the proposed guidance is examined experimentally in a rectangular space. Finally, the effectiveness of the proposed guidance is examined in an actual car. It is shown that the proposed guidance is shown to be satisfactory.