Sound insulation analysis of solid walls using the finite element method

Abstract

In times of increasing noise pollution, the numerical simulation of sound transmission through solid walls, e.g., of masonry, is a challenging building acoustics topic. For an adequate building design tool it is of great importance to take arbitrary geometrical and acoustical boundary conditions as well as the air–structure interaction into account. Here, a model based on the finite element method is presented for the calculation of sound propagation in layered air/wall/fiber systems. The structure-borne sound is, on the one hand, influenced by the bending waves and, on the other hand, by the in-plane waves, if also the flanking transmission is investigated, where the bending waves are modeled by the Mindlin plate theory and the in-plane waves by the dynamic elastic disk equation. The acoustic behavior of air is described by the Helmholtz equation. The fluid–structure interaction is performed by using the principal of virtual work, and, as a final result, a completely coupled methodology is derived which allows the determination of sound fields and of the transmission loss of conventional solid walls. Numerical results are compared with measured values and the influence of various parameters is studied.