伝達行列法を用いた線状周期構造物の振動特性に関する研究 : 1次元連続体と集中質点で構成される周期構造の波動伝播特性に関する基礎的考察

抄録

The wave propagation in the periodic structure is studied using the transfer matrix method. The large space structures such as a NASA's space station are made of truss structures which are ones of the periodic structures composed of pipes and joints. Since the space station will be used for the experiment and manufacturing utilizing micro G environment in space, it is necessary to control the vibration below μG under several external disturbances which have a wide band frequency range. In order to assure the vibration control, the basic study on the wave propagation in the periodic structure should be carried out. In this paper, a simple model of one-dimensional continuum body attached by lumped masses with same spacing is adopted. A study on the eigenvalues of the transfer matrix enables us to understand the wave propagation phenomena of the periodic structure which have pass band and stop band. The evaluation of the phase velocity, group velocity and equivalent damping makes us confirm the dynamic characteristics of the periodic structures. As a extreme case, the system composed of lumped mass and static spring is studied in order to grasp the wave propagation in the discrete system.