Tech Papers

[14] Modelling of Transmission loss for trimmed vehicle components

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 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. Recent theoretical developments removed this limitation by providing a FEM formulation for poro-elastic material modelling. Using a FEM only approach, this new theory was successfully used to compute the coupled vibro-acoustic response of a fully trimmed vehicle, which includes the BIW structure, the acoustic fluid and the poro-elastic materials (seats, carpet, dash insulator…). The latest development of powerful algorithms allows the automatic model setup and high performance parallel calculation to be performed fast enough to be implemented into the sound package design process of large OEMs. Most recent developments allow the automatic Transmission Loss (TL) model building process of complex components such as trimmed dash or floor. This paper presents a comparison between different types of cabin side dash insulators using the development described above and compares these predictions with test.

2007 – JSAE, Yokohama, Japan
Lassen Mebarek (ESI Group, France)
Sosthene Lullier (Treves, France)
Yukinori Kobayashi (Kotobokiya Fronte, Japan)
Denis Blanchet (ESI Group, France)

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