Prediction of the sound transmission loss of a stiffened window

The sound transmission loss of a stiffened window was investigated using a coupled finite element and boundary element method. This approach allowed the window to have arbitrary elastic boundary conditions and the stiffeners to be located at arbitrary positions inside the window. The in-plane deformation of the window was also taken into account. The natural frequencies predicted by the present approach showed good agreement with earlier published results. The prediction method was subsequently applied to parametric studies examining the effects of stiffeners on the sound transmission loss of a window. The results showed that the stiffeners (or their locations) notably influenced the window's sound transmission loss values, thereby demonstrating the possibility of using stiffeners to improve the sound insulation of a practical window.Practical applications: This study provides an approach that can be used to predict the sound insulation of a window with arbitrary elastic boundary conditions and with any-shape stiffeners lying anywhere inside the window. This approach can also be used to guide the design of windows (or other plate-like building structures) with better sound insulation.