動質量行列を用いた入力同定手法の提案(<特集>D&D 2008)

Abstract

Transfer Path Analysis (TPA) is a key technology for tackling with the noise and vibration problems, and the precision of the identification influences the result of contribution analysis. For the identification of input force, the matrix inversion method is commonly used as an indirect method where the pseudo-inverse of the FRF matrix is multiplied to the response spectra to estimate the input force spectra in a least-square sense. This paper presents a new approach to improve the accuracy of the input identification by the matrix inversion method. To avoid the inversion of the ill-conditioned matrix, the apparent-mass matrix (force/acceleration FRF matrix) is directly estimated in a vibration test. In this paper, the accuracy of two identification methods are compared by applying two approaches to FEM analysis and a vibration test. And it is shown that the identification accuracy by the apparent-mass matrix approach is superior to the matrix inversion method.