Vibration Analysis of Ship Structures in Consideration of Fluid-Structure Insteraction

In the vibration analysis of today's weight-optimized ship structures, it is very easy to find the non-beam like modes of vibration such as the double bottom vibration or the local vibration in ships with large openings. However, it is not easy to find the added mass and the corresponding three dimensional reduction factors. It is well known that the hydroelastic vibration analysis of structures in contact with fluid can be solved by applying the finite element method to structures and the boundary element method to fluid domain. However, such an approach is impractical due to the characteristics of the fluid added mass matrix fully coupled on the whole wetted surface. To overcome this difficulty, an efficient program MOFSIA(Modal Fluid-Structure Interaction Analysis) based on the modal coupling of fluid-structure interaction using reanalysis scheme is developed fur the free and forced vibration analysis of the arbitrary wetted structures with various fluid boundary conditions such as side wall, sea bottom or dock bottom, free surface and radiating boundary. The efficiency and accuracy of calculated results using the program MOFSIA developed by this project has been proved through the vibration experimental measurements of the plate model and the ship model, and also through the numerical experiments for the same models and 3200 TEU container ship.