Sound insulation properties of embedded co-cured composite damping sandwich panel under arbitrary boundary conditions

Abstract

The embedded co-cured composite damping structures (ECCDS) are widely used in engineering fields, it is necessary to build a predictive model of the dynamics of the ECCDS panel. In this paper, a method is promoted for the first time that can predict the acoustic-vibration coupling characteristics of the coupled cavity-ECCDS panel-cavity system. This paper innovatively combines the spectral-geometry method (SGM), penalty-function method (PFM), and the energy-generalised variational principle to develop coupling model of the ECCDS panel with two closed cavities. The displacement of the ECCDS panel and the sound pressure in the cavities are expressed as improved Fourier series. The modal parameters of the cavities and the ECCDS panel are obtained by solving the standard matrix eigenvalue problem, and the accuracy of this method is verified by comparing it with the finite element method (FEM) and experiment. On this basis, the sound transmission loss (STL) can be obtained by the sound pressure method. The factors affecting the sound insulation performance of the ECCDS panel are investigated by parametric analysis. The results show that the addition of a damping layer can improve the sound insulation performance of composite panels. This paper provides a reference for the application of ECCDS panels in engineering.