On the numerical modeling of poroelastic layers in spring-mass systems

Abstract

The proper modeling of noise control treatments is a key factor in the robustness of the numerical prediction of the sound transmission under airborne excitation. 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 with other components. In this article, three different material formulations derived from the poroelasticity theory are employed to describe the poroelastic middle layer of a spring-mass system. The calculated results are contrasted with data measured in a window test bench. It is observed that for the description of softer materials the full poroelastic formulation provides the most accurate results. Conversely, a description as an elastic solid yields the best results for stiffer poroelastic layers. Moreover, the utilization of frequency-dependent elastic properties improves the match between numerical and experimental results, especially in the high-frequency range.