THE SENSITIVITY ANALYSIS METHOD OF COUPLED ACOUSTICS-STRUCTURE SYSTEMS AND APPLICATIONS IN INTERIOR NOISE REDUCING

摘要

This paper studies the numerical simulation and sensitivity analysis of coupled acoustic-structure systems with finite element method and applications in the interior noise reducing. The finite element method is used in our research to calculate the coupling responses of the acoustics-structure systems. The modal analysis of acoustic-structural system is performed to obtain the frequencies and modes, and then, to estimate the acoustic pressure distribution and noise magnitude. The modal analysis of coupled acoustic-structural system leads to an unsymmetrical eigenvalue problem in special form, which introduces different left and right eigenvectors. According to this problem, new orthogonal condition and normalization condition are derived for coupled system. With the new defined orthogonal and normalization conditions, the finite element method to compute the eigen-pairs and their sensitivity derivatives of coupled systems are proposed. The numerical simulation and, particularly, the sensitivity analysis of coupled acoustics-structure systems have provided efficient computational tool for the noise reducing and vibration control with design optimization on structural and material parameters. These numerical methods have been implemented in a finite element software system, JIFEX, to the application of interior noise reducing in acoustic structural designs. The application and effectiveness of the methods presented in the paper are illustrated by some examples.