Tech Papers

[15] Theoretical Foundation for the Modeling of Transmission Loss for Trimmed Panels

In the automotive industry, the influence of poro-elastic components on acoustic comfort has been mostly investigated for air borne noise at mid and high frequency ranges. However, due to the lack of adequate theoretical formulations, the influence of poro-elastic material in numerical vibro-acoustic simulation at lower frequency range has often been ignored or roughly approximated by the addition of distributed spring/mass on the BIW structure. This paper presents the theoretical formulation for the calculation of the acoustic Transmission Loss (TL) of simple or double wall trimmed panels. The poro-elastic materials are described by a FEM model describing geometry and the intrinsic properties of the trim: the BIOT parameters. This method provides an efficient way of building predictive models of a
trimmed structure. The resulting Transmission Loss module is implemented in ESI-GROUP software solutions. Numerical results are compared with other software tools available on the market and with experimental data.

2007 – JSAE, Yokohama, Japan
Abder Omrani (ESI Group, France)
Denis Blanchet (ESI Group, France)
Hideki Niwa (Nippon Sharyo, Japan)

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