618 一部を開放した空間のモーダル周波数応答解析(OS6-2 機械力学(2)音の解析・制御技術)

抄録

In order to clarify a noise and vibration phenomenon and to take an appropriate measure for it, a dynamic model is usually built. The equations of the dynamic model is often diagonalized by eigenvectors of the eigenvalue analysis. So the equation becomes much easier to be solved. This calculation scheme is called a modal analysis. Matrices are symmetry. Generally the equation of motion is given as [M]{x^^‥}+[C]{x^^・}+[K]{x}={f}. [M] mean mass matrix etc. Infinite elements are used for a space with open areas in finite element method. In that case, damping matrix becomes asymmetry. So that is not clarified that the modal analysis is applicable or not. The purpose of this study is to apply the modal frequency response analysis for some models with open areas. They are a sound pipe with infinite elements and a three dimensional space with infinite element. A sound pipe with infinite elements is clarified that the modal analysis is applicable but a three dimensional space with infinite element needs study to be applicable.