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Integration of acoustic material concepts into vehicle design process is an important part of full vehicle design. The ability to assess the acoustic performance of a particular sound package component early in the design process allows designers to test various design concepts before selecting a final solution and long before a design freeze. This paper describes an innovative acoustic material concept which is easily integrated in a design process through the use of vibro-acoustic simulation and a database of intrinsic properties of acoustic materials: The Biot Parameters. Biot parameters are widely used in simulation in many industries (and used the most in the automotive industry) to describe the physical interactions between the acoustic waves travelling through foams, fibers or homogeneous metamaterials and the solid and fluid phase of these poro-elastic materials.

It is well known today that Biot parameters are the intrinsic material properties of porous media such as foams and fibers. They are to porous media what Young’s modulus is to steel panels. Once these Biot parameters are accurately known, one can trust that a predictive simulation model will yield the corresponding level of accuracy. But how accurate must these Biot parameters be to warrant a safe level of accuracy of the resulting simulation models? This paper analyzes various round-robin tests publications related to measurements of Biot parameters (acoustic and elastic) and uses the reproducibility of measured data from the numerous laboratories involved to evaluate the effect of the observed measured variability on simulation models accuracy when predicting transmission loss, surface absorption and actual sound pressure level (SPL) response inside a vehicle.