On the Numerical Modeling of Poroelastic Materials in Acoustic Analysis

The proper modeling of noise control treatments is a key factor for the robustness of the numerical prediction of the sound transmission. Typical acoustic treatments applied in the industry include one or more layers of poroelastic materials. These are particularly challenging to model since they exhibit a complex, high dissipative behavior that is not only dependent on the material properties, but also on the interactions to other components. In this contribution, three different material formulations derived from the poroelasticity theory are employed to describe the poroelastic layers. In addition to these material models, a simplified approach based on a homogenized viscoelastic material behavior is tested. For this approach, the frequency-dependent stiffness and damping behavior of the damping material is determined in advance with the help of a vibrational test bench. Three different concepts for the noise reduction based on poroelastic materials are tested, namely, the insulation through a spring-mass component and the absorption of a porous layer as well as a combination of both. Moreover, three different test setups are investigated. At first, the sound transmission through a plate with an applied damping material is studied. Further, a simplified model of a vehicle’ front end is investigated. The calculated results of both setups are contrasted with measured data. The measurements are executed in a window test bench. Thirdly, a structurally excited plate with an attached damping layer is investigated in an anechoic room in terms of its radiated sound power. Finally, all mentioned approaches are compared and recommendations on the modeling approaches as well as an outlook are presented.