Abstract:

A semianalytical sensitivity analysis method is proposed to calculate the eigenvalue and response sensitivity for a coupled vibroacoustic system. This sensitivity information can be used in a design trade-off study or in a formal design optimization procedure. In this study, an acoustic finite-element method is used to compute the eigenvalues, eigenvectors, and responses of the acoustic interior problems. A symmetric form of the coupled equation is used here. By directly differentiating the coupled equation, it can be shown that the sensitivities of the coupled systems depend only on the eigenvalues, eigenvectors, and the derivatives of coefficient matrices of the coupled equation. These coupled sensitivities will be demonstrated for a coupled plate and box problem. Numerical results will be given for the sensitivity of elastoacoustic frequencies due to the change of plate thicknesses and the sensitivity of interior pressures due to the change of acoustic absorbing materials.