Sound Radiation from an Elastically Restrained Plate Covered by an Acoustic Decoupling Layer

Abstract

The sound radiation from elastically restrained plates covered by a decoupling layer is studied using the Spectrogeometric Method (SGM), which is a meshless and parametric modeling technique. By adopting the Rayleigh-Ritz procedure and the Rayleigh integral, a vibroacoustic coupling system is established. This model studies the situation when the plate is immersed in heavy fluid, such as water, in which the strong coupling between the structure and sound field should be fully considered. The influence of the boundary conditions on the radiated sound power and sound reduction provided by the decoupling layer based on the locally reacting model is studied. The nonuniform distributed decoupling layer is also studied to analyze the sound reduction effect. The sound intensity on the outer surface of the decoupling layer is investigated and tends to be uniform along the plate scale with increasing thickness of the decoupling layer.

Experimental and Theoretical Analysis for a Fluid-Loaded, Simply Supported Plate Covered by a Damping and Decoupling Composite Acoustic Coating

“…represents the natural angular frequencies of the base plate and damping layer composite. Substituting (15), (22), (23), and (24) into (12) results in the following equations:…”

“…In this paper, three vibroacoustic indicators are introduced: the mean squared velocity of the base plate (V 2 1 ), the mean squared velocity of the outer surface of the decoupling layer (V 2 2 ), and the radiated sound power by the system in water ( ). The definitions of the vibroacoustic indicators have been previously published [14,15,17].…”

“…The first of model is based on the theory of wave propagation in a layered media [9] and is derived using an impedance transfer matrix [10][11][12], which just regards the tensile stresses and longitudinal waves in the decoupling material. The second type is the locally reacting model [13][14][15][16], which assumes that the decoupling material behaves as a set of evenly distributed massless springs on the plate. Such models however remain limited by their inherent inability to capture the complex propagation of elastic waves in the decoupling material [17].…”

A Study on the Scattering Energy Properties of an Elastic Spherical Shell in Sandy Sediment Using an Improved Energy Method

“…The statements of the elasticity problem about the wave propagation in an elastic cylindrical waveguide under different radiation conditions at infinity are considered by Nazarov [14]. The sound radiation from elastically restrained plates covered by a decoupling layer is studied using the Spectrogeometric Method by Wang et al [15]. Present researches are focusing on the time average of the instantaneous energy flux.…”