Vibration Dynamics Modeling of Anisotropic Porous Foam Materials
2005 (English)Conference paper (Refereed)
For an accurate prediction of the low to medium frequency surface vibration and sound radiation behavior of multilayer trim components with polyurethane foam core materials, improved means of estimating the dynamic elastic and damping properties of the foam are necessary. This is due to the fact that in the manufactured porous polyurethane foam materials typically used in acoustic trim components, there is a geometric anisotropy in the foam cell microstructure. The foam cells and struts are elongated in the rise and injection flow directions of the manufacturing process. The density, elastic and damping properties of the foam can then be considered to be highly dependent upon manufacturing process techniques, along with the polyurethane chemical formulations. For a balanced cost and acoustic performance optimization of these materials in the product development cycle, it is important that this inherent anisotropy is correctly represented in the acoustical numerical simulation methodology. Through a hybrid combination of experimental deformation and strain field mapping, and physically based porous material acoustic Finite Element (FE) simulation modeling, the anisotropic dynamic elastic coefficients and damping properties of the foam may be correctly estimated. This new methodology of model-based porous material characterization is demonstrated here for a simplified seismic mass configuration. The improved accuracy of the subsequent low-mid frequency multilayer surface vibration numerical predictions is discussed. This leads to improved NVH analysis during the development lifecycle of the vehicle acoustic sound package, allowing a better balance between acoustic performance and a minimization of material usage to be achieved.
Place, publisher, year, edition, pages
2005. 123-128 p.
Fluid Mechanics and Acoustics
IdentifiersURN: urn:nbn:se:kth:diva-82488ScopusID: 2-s2.0-84864588299ISBN: 978-963824168-9OAI: oai:DiVA.org:kth-82488DiVA: diva2:498281
4th European Congress on Acustics, Forum Acusticum 2005; Budapest; Hungary; 29 August 2005 through 2 September 2005
QC 201409292012-02-112012-02-112014-09-29Bibliographically approved