Acoustic design of a three‐layered plate with high sound interception

This paper presents a study on the transmission characteristics of a three‐layered infinite plate excited by a plane acoustic wave. Each layer is described by the two‐dimensional elasticity theory. An expression predicting the sound transmission loss as a function of both the frequency and the incidence angle of the acoustic wave is derived and calculated numerically for various combinations of the facing and the core materials. Further, based on the information thus obtained, a method to fabricate a sandwich plate with high sound interception is presented and applied to the design of a plate consisting of a steel core and foamed concrete facings.