Title: Structural-acoustic mode synthesis for vehicle interior using finite-boundary elements with residual flexibility

Authors: Bazil Thomas, Randy J. Gu

Addresses: Department of Mechanical Engineering, Oakland University, Rochester, MI 48309, USA. Department of Mechanical Engineering, Oakland University, Rochester, MI 48309, USA

Abstract: A novel method of combining modal synthesis and residual flexibility for structure and boundary elements for fluid to compute the acoustic pressures in an enclosed cavity that might have application in automotive industry is studied. Traditionally in the automotive industry, both the fluid cavity and the enclosing flexible structure are modelled using finite elements to find the acoustic pressures. A method is proposed where the flexible structures such as automotive panels are modelled using finite elements available in any commercial software package and fluid cavity is modelled using boundary elements. This approach substantially reduces modelling and computing effort required for fluid cavity. Modal synthesis and residual flexibility vectors to account for the truncated higher frequency modes of the flexible interacting structure are utilised to improve the accuracy. Results of the new technique are compared against two other methods, namely, direct frequency method and the case where both the structure and the fluid are modelled using finite elements.

Keywords: acoustics; FEA; BEA; residual flexibility; modal synthesis; structural-acoustics.

DOI: 10.1504/IJVD.2000.001891

International Journal of Vehicle Design, 2000 Vol.23 No.1/2, pp.191-202

Published online: 18 Aug 2003 *

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