水圧計測による波浪中船体構造応答の推定手法

Abstract

It is important for the design of the safe hull structure to grasp the hull structural response in waves. A seakeeping test by using a flexible ship model is carried out to clarify hull structural response in waves. But it is difficult to design and deal with a flexible ship model. In this study, the estimation method available to a rigid ship model for hull structural response is proposed. First, hydrodynamic pressure in the hull surface is measured by conducting a seakeeping test. Next, the hydrodynamic pressure is interpolated in the whole hull surface considering the hydrodynamic pressure distribution near the draft. Finally, the hydrodynamic pressure distribution is used as load and finite element analysis (FEA) is carried out. Inertial force is considered by using the inertia relief method. The hull structural response in waves can be obtained from FEA results. In this 1st report, a seakeeping test is carried out, and the vertical bending moment (VBM) is estimated by using the proposed method. An acrylic flexible ship model is used in the test to measure the hydrodynamic pressure on the hull outer surface and hull strains at many points by using the fiber Bragg gratings sensors. VBM obtained by the proposed method is good agreement with one obtained by the measured strains.