An efficient wave based approach for the time-harmonic vibration analysis of 3D plate assemblies

For the analysis of the vibrational behaviour of mechanical structures the Finite Element Method (FEM) and the Statistical Energy Analysis (SEA) are most commonly used. The use of the FEM is limited to low frequency applications, since finer meshes are required at higher frequencies to preserve the same accuracy, hence increasing the computational load. The use of SEA is mostly limited to high frequency applications, due to its underlying assumptions. This paper discusses the principles of the Wave Based Method (WBM) for the steady-state dynamic analysis of thin, flat plates coupled at an arbitrary angle, including both out-of-plane and in-plane plate behaviour. Two numerical examples illustrate the beneficial convergence rate of the WBM and show the importance that in-plane displacements can have in the simulation of non-coplanar plate assemblies. As a result of its higher efficiency, the WBM is able to relax the existing frequency limit of the FEM and in this way can reduce the mid-frequency gap which exists between the low and the high frequency techniques. Furthermore, it can be used to provide more accurate input parameters for SEA-calculations in order to lower the frequency range of SEA.