A novel prediction technique for the steady-state dynamic analysis of coupled vibro-acoustic systems

A new prediction technique has been developed for the steady-state dynamic analysis of coupled vibro-acoustic systems. The technique is based on the indirect Trefftz method, in which the dynamic field variable expansions are exact solutions of the governing dynamic equations. This paper presents the basic principles of the prediction technique and applies it for the modelling of a three-dimensional plate-cavity coupling problem. This application illustrates that a high accuracy is obtained from substantially smaller models, compared to the finite element method, since an approximation is induced only in the representation of the boundary conditions. Moreover, a comparison between the new technique and the conventional finite element method reveals the beneficial convergence rate of the new technique, in that it provides accurate prediction results with a substantially smaller computational effort. In this way, the new technique can be applied up to much higher frequencies than the conventional finite element method.