ポンツーン型浮体の波浪中弾性応答解析へのＨａｍｉｌｔｏｎ−Ｄｉｒｉｃｈｌｅｔ原理の適用（第２報：任意平面形状浮体への適用）

Abstract

Many analytical methods have been proposed to calculate hydroelastic responses of a very large pontoon type structure in waves.In relation to the elastic response of such pontoon type structure in waves, Isshiki and Nagata proposed the Modified Hamilton-Dirichlet's Principle 2, which is expressed only using the velocity potential. It is the variational principles related to motions of the elastic floating plate on a water surface.In this study, in order to calculate the wave-induced responses of an elastic floating plate in waves, a new method was proposed which uses the Modified Hamilton-Dirichlet's Principle 2and the eigenfunction expansion method for fluid motion. The velocity potentials in fluid regions with and without the plate are expanded by eigenfunctions in vertical mode which satisfy the governing equations and free-surface conditions, taking into account the presence of the plate in the same manner as Kim and Ertekin. In this method, Modified Hamilton-Dirichlet's Principle 2 is finally reduced to a variational equation which corresponds to boundary conditions on the plate's edge. The formulation of proposed method is applicable for the floating plate of arbitrary plan geometry.Calculated results of two kinds of rectangular and L-shaped floating plate in an open sea are compared with experimental results.Good agreement is found between computed and experimental results.