Identification of sound transmission characteristics of honeycomb sandwich panels using hybrid analytical/one-dimensional finite element method

For the purpose of identifying the sound transmission characteristics of honeycomb sandwich panels that are commonly used in aircraft industries, Finite Element Method (FEM) combined with Boundary Element Method (BEM) has been widely used. However, the latter approach is not always applicable to high frequency analysis since it requires a large number of FEM/BEM meshes resulting in high computational cost. Although various analytical methods can also be used, their applications are restricted to few panels, e.g., that have simple layer configuration. Here, a hybrid analytical/one-dimensional FEM is described that uses finite element approximation in the thickness direction while analytical solutions are assumed in the plane directions. Thus, it makes possible to use small number of finite elements even for high frequency analysis in computationally efficient manner. The proposed method can be used to analyze the effects of boundary conditions at the edges of a panel. It can also be used to analyze various multi-layered panels of which each layer is represented by orthotropic material properties. As an application, the sound transmission characteristics of infinite-size panels are analyzed. By comparison with experimental data, it is shown that the proposed method successfully identify the sound transmission characteristics of honeycomb sandwich panels.