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Automotive suppliers provide multi-layer trims mainly made of porous materials. They have a real expertise on the characterization and the modeling of poro-elastic materials. A dozen parameters are used to characterize the acoustical and elastical behavior of such materials. The recent vibro-acoustic simulation tools enable to take into account this type of material but require the Biot parameters as input. Several characterization methods exist and the question of reproducibility and confidence in the parameters arises. A Round Robin test was conducted on three poro-elastic material with four laboratories. Compared to other Round Robin test on the characterization of acoustical and elastical parameters of porous material, this one is more specific since the four laboratories are familiar with automotive applications. Methods and results are compared and discussed in this work.

When it comes to the design of multi-functional automotive interior floors, engineers face the challenging conflict between a dynamically-soft, NVH performing treatment, and a statically-stiff construction, which increases the perception of solidity. Nowadays, the former requirement is well-specified and advanced CAE tools exist to support performance prediction and engineering of the construction. On the contrary, neither well-established requirements specify the compressional performance, nor defined CAE processes are available to support the engineer in its prediction. In this context, the aim of this paper is twofold. Firstly, insightful conclusions about the compression behavior of typical interior floor materials are drawn by means of tests carried out both at sample- and part-level. Such an analysis allows highlighting a clear direction towards meaningful assessment of the mechanical characteristics of the floor.

In automotive acoustics, body NVH design is traditionally carried out without considering the acoustic trim parts. Nevertheless, the vibro-acoustic interaction of body structure and insulation trim cannot be neglected in the middle frequency range, where structure borne propagation might still be dominating and where classical statistical approaches are generally not able to represent the influence of local changes in stiffness and damping. This, together with the market requirement of lightweight and more efficient sound package solutions, is leading the CAE engineers to evaluate new design approaches dedicated to vehicle components such as dash or floor systems, for which the multi-physics interaction between damping, body stiffness and trim impedance is important.