主催: 一般社団法人 日本機械学会
会議名: Dynamics and Design Conference 2019
開催日: 2019/08/27 - 2019/08/30
It has been shown that passengers have large reduction effect on the elastic vibration of a railway vehicle carbody. That effect is considered due to the viscoelastic motion and multi-directional motion of a human body. This study focuses on the latter one and aims to develop a new vibration reduction device to mimic the multi-directional motion of passengers. The study so far, an experimented multi-directional dynamic vibration absorber (called MDDVA in this report) is developed. The MDDVA consists of a steel ball supported resiliently by elastic balls bottled in a rigid cylindrical vessel. The steel ball can vibrate multi-directionally in the vessel and is expected to work as an MDDVA. In addition, the natural frequency of the MDDVA can be changed by pressing the elastic balls from the top. To evaluate the effectiveness of the MDDVA, excitation tests by means of a scale model of a railway vehicle is conducted. As a result, the MDDVA can reduce the elastic vibration by adjusting the natural frequency of MDDVA to that of the scale model, and multi-modal vibration reduction effect is successfully observed. And then, FEM models of the MDDVA and a scale model are constructed to verify the mechanism of the multi-modal vibration reduction. As a result of the FEM analysis, it is confirmed that the multi-directional motion of the steel ball produces the multi-modal vibration reduction effect. This paper aims to construct FEM models of the MDDVA to be used for design. New FEM models of the MDDVA, which the elastic balls can be pressed from the top as with the actual MDDVA, are constructed. As a result of the FEM analysis with level changes of pressing the elastic balls, it is confirmed that a tendency of test accords that of FEM analysis. However, improvement is necessary to design the MDDVA quantitively.
