Prediction of noise transmission through infinite panels using a wave and finite element method

Abstract

The transmission of sound through simple infinite isotropic panels can be predicted in a straightforward manner using well-established analytical models. However, such models become difficult to implement for more complicated structures such as laminates etc. In these cases, numerical approaches such as the finite element method are viable alternatives. However, these methods can be computationally intensive as the entire structure must usually be meshed with the surrounding fluid being modelled using finite, infinite or boundary element methods. This paper describes the extension of a Wave and Finite Element (WFE) method for the prediction of sound transmission through infinite, two-dimensional panels. Excitation of the structure by oblique plane waves, a diffuse sound field and a point force are all considered. The WFE method involves a finite element model of a small segment of the panel from which the wave properties and the response to external excitation can be found. Because the WFE method only involves meshing a small segment of the panel, computational times are significantly less than a full finite element simulation. Two example applications of the method are described, namely a thin isotropic panel and a laminated panel.