抄録
In ship structures, many parts are in contact with water as stern, ballast and oil tanks. Fatigue damages can be sometimes observed in these tanks which seem to be caused by resonance. Tank structures in ships are in contact with water and the vibration characteristics are strongly affected by the added mass of containing water. Therfore it is important to predict vibration characteristics of tank structures. But, it is difficult to predict the vibration of tank structures because of the effect of added mass of water. The added mass is affected by the free surface, vibration modes of plates and the depth of water. In order to estimate the vibration characteristics, the fluid-structure interacion problem has to be solved precisely. In the present paper, we have developed a numerical tool of vibration analysis of 3-dimentional tank structures using finite elements for flats and boundary elements for water region. And the added mass effect of containing water and the effect of structural constraint between panels are investigated numerically and discussed.
