Abstract
To study the sound field of a structure-acoustic coupling system, numerical analysis techniques are often used. But numerical analysis techniques are not fit to clarify systematically the features of the sound field. In this paper, an attempt is made to clarify systematically the features of the sound field in a rectangular parallelepiped with a flexible panel at one end. First, experimental study is conducted using an experimental model. Its eigenfrequencies, mode shapes are measured, and features of the sound field are discussed. It is found that in the response there is a fixed state, which is unaltered by a modification of the structure. Secondly, theoretical study is made using a one-dimensional mathematical model. It is found this model can explain all the features obtained experimentally.
