Abstract
One of the objects of this paper is to formulate for the coupling problems of the three dimensional body and the shell to the water wave systems under the linear elastic theory, another is to show some numerical analysis for its application. In marine structures, the deformation of a structure and the wave motion of a fluid are dynamically interaced on each other through their interface boundary. But it is difficult, for various marine structures, to be given an exact solution considering the influence of those interaction. Formulating with the aid of discrete expression the coupled field of a structure and a fluid, the dynamic behaviours of the marine structure and the dynamic pressures of the water wave can be easily obtained together. Then, in this paper, the equations of motion to those coupling problems are generally derived in discrete formulating by means of the weighted residual method, expressed the parameter of a fluid in terms of a pressure or a velocity potential. Moreover, as an application of these formulation, the numerical results by the finite element method are indicated in about axisymmetric free vibration and up-down earthquake response analysis of a spherical shell fixed on the sea bed.
