Finite Element Subvolume Technique for Structural-Borne Interior Noise Prediction

Abstract

Finite element structural and acoustic representations of a vibrating structure and enclosed acoustic volume are used in a study of structural-bo rne interior noise. The direct finite element nodal representations of the equations of motion result in a large system of unsymmetric equations. In this paper, an acoustic subvolume analysis technique is presented which reduces the degrees of freedom of the interior volume to modal form prior to the coupled system dynamic analysis. Analytical predictions are compared to results from an experimental program to verify the analysis procedures. From these comparisons, the acoustic subvolume technique is shown to be a reliable method to reduce the computational requirements for finite element acoustic analysis.