三次元直交異方性を有する直方体の固有角振動数と固有モード

抄録

The natural angular frequencies and natural vibration modes of the three-dimensional orthotropic rectangular parallelepiped are investigated. A lot of studies have been done on the orthotropic laminated composite materials, but few studies have been done on the materials that are not made of layers. Previously, we studied the case that all the mode orders at each axial direction were same. In this report, the case of the different mode orders each other is studied. Same as our previous reports, in the relationships between dimensions and natural angular frequencies, there are ranges where the natural angular frequencies vary linearly, they are almost constant and the intermediate range between them. In the relationships between the length and the natural angular frequencies, the entire curves move in the increasing direction of the length by a factor of the modal order in the length direction when only it is changed. When both the mode orders in the thickness and width directions are changed in the same manner, the curves move in the decreasing direction of length by the reciprocal of the mode orders. The eigenvectors are unchanged in the range of the natural angular frequencies varying linearly and the range of them being almost constant.