抄録
The previous reports by the authors presented analytical methods for determining the sensitivities of the eigenvalues and eigenvectors and the sensitivity of the direct frequency response (DFR) of coupled acoustic-structural systems, with the aim of reducing vehicle interior noise levels. As a continuation of the previous studies, this paper deals with an investigation of the modal frequency response (MFR) of coupled systems and proposes methods for analyzing their MFR sensitivities. Two types of analytical methods are derived for determining the MFR sensitivities ; one is based on the eigenpair sensitivities of a coupled system and the other on the direct differentiation of the modal frequency response. It is shown that the latter method can also be derived from the DFR sensitivity and that it is a more effective method in terms of calculation accuracy and efficiency. A coupled acoustic-box model and a coupled acoustic-vehicle model are analyzed to confirm the applicability of the proposed methods to actual noise analysis problems.
