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

Abstract

This work presents a vibroacoustic response model for a fluid-loaded, simply supported rectangular plate covered by a composite acoustic coating consisting of damping and decoupling layers. The model treated the damping layer and base plate as a unified whole under pure bending moments and the decoupling layer as a three-dimensional, isotropic, linear elastic solid. The validity of the model was verified by both numerical analysis and experiments and was shown to accurately extend previous studies that were limited to a plate covered by a single damping or decoupling layer with an evaluation confined solely to numerical analysis. The trends of the numerical and experimental results are generally consistent, with some differences due to the influences of water pressure and the frequency dependence of the material parameters, which are not taken into account by the numerical analysis. Both experimental and numerical results consistently show that the radiated noise reduction effect of the composite coating is superior to that of single-type coatings, which is attributed to the fact that the composite coating combines the merits of both the high vibration suppression performance of the damping layer and the superior vibration isolation performance of the decoupling layer.

Noise radiated from a periodically stiffened cylindrical shell excited by a turbulent boundary layer

“…It was shown that the wave reflection produced by the stiffeners changed the dispersion relationship and caused the panel to be excited in a coincidental manner by incident sound waves, at frequencies below the critical frequency. Additionally, Yuan et al [7] numerically and experimentally studied the vibroacoustic response of a fluid-loaded, simply supported rectangular plate covered by a composite acoustic coating. They found that only when the loss modulus of the damping layer was sufficiently high and the stiffness of the decoupling layer was sufficiently low, the system can provide an excellent vibration isolation and noise reduction effect.…”