Efficiency requirements prompt manufacturers to develop ever lighter acoustic packages in vehicles. Poroelastic materials are essential to achieve the desired interior noise level targets and thus the simulation of their effects is of utmost importance in NVH analyses. However, it is challenging to achieve good validation between finite element method (FEM) based simulation results and measurements in the mid-frequency range (400-1000 Hz). One possible reason could be the lack of using frequency-dependent Biot-paremeters describing the poroelastic materials (PEM) characteristics of trims. The present research aims to employ frequency-dependent Biot-parameters for the PEM materials to investigate the acoustic response of a scaled car-like steel structure composed of flat plates and U-section stiffeners enclosing an air cavity. Porous acoustic material is applied to the walls of the cavity. The focus of the study is to understand the effect of applying frequency-dependent Young's modulus and damping values for the PEM parameters in the 100-1000 Hz range. Simulation results obtained from ESI VPS FEM solver are compared with measurements, with particular focus on the interior sound pressure levels. The simulation methodology, including discretization techniques, structural damping and fluid damping applications are described in detail.

Recent trends in vehicle engineering require manufacturers to develop products with highly refined noise, vibration and harshness levels. The use of trim elements, which can be described as Poroelastic materials (PEM), are key to achieve quiet interiors. Finite Element Methods (FEM) provide established solutions to simple acoustic problems. However, the inclusion of poroelastic materials, especially at higher frequencies, proves to be a difficult issue to overcome. The goal of this paper was to summarize the state-of-the-art solutions to acoustic challenges involving FEM-PEM simulation methods. This involves investigation of measurement and simulation campaigns both on industrial and fundamental academic research levels.

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