Proceedings of the International Conference on Noise and Vibration Engineering (ISMA2014) pages:4233-4248
International Conference on Noise and Vibration Engineering edition:ISMA2014 location:Leuven (Belgium) date:15-17 September 2014
With ever more stringent requirements on noise and vibration levels, engineers often rely on multilayered damping treatments to improve the sound and vibration properties of their products. The modelling of the vibro-acoustic behaviour of these treatments is, however, far from trivial. The current state of the art CAE tools, such as the Finite Element Method (FEM), are in practice limited to low-frequency simulations due to the strongly increasing computational cost with frequency. This increase is caused by the short wavelengths involved, requiring a very fine element discretisation, and by the (strongly) frequency dependent material parameters which hamper the straightforward the application of modal reduction schemes. Introduction into vibro-acoustic system models also requires a further refinement of the system model mesh to be able to
capture the very localised near field effects of the multilayer treatments.
Therefore, research effort is still invested in the reduction of the computational cost, both from the
conceptual, as well as from the methodological side. In some cases, conceptual approximations to the multilayer models can be made, such as e.g. using equivalent fluid models rather than full Biot models for poroelastic materials, or assuming 1,5D wave propagation through the multilayer. Although well-established on a component level, the impact of these approximations on the vibro-acoustic system level has hardly been studied because of the computational burden. This contribution studies the impact of model approximations
made in the multilayer components on the overall efficiency and accuracy of vibro-acoustic simulations.
The Wave Based Method (WBM) and its hybrid extensions are used to facilitate fast and efficient numerical