Study Of Wave Load Responses Of Large Ship Considering Elastic Effect

High strength steels are increasingly used in ship construction in order to ensure the structural strength and safety of large ships.However,the use of high strength steel results in a problem of lower stiffness of ship structures.Consequently,large ships are prone to elastic deformation when navigating in waves,and which has a significant impact on the wave load response of the ship.Thus,the elastic effects shall be considered when predicting wave loads on large ships.This thesis aims to investigate,numerically and also numerically,the influence of elastic effects on the wave loads of large ships.The main contents of this thesis include:Firstly,a 3D linear and also a 3D nonlinear hydroelastic theories that account for the coupling effects between elastic deformation and fluid field are compared and analyzed,including their characteristics as well as the applicability.Secondly,an experiment is devised and carried out to investigate the elastic effects.A series of tank tests have been conducted with a rigid and also an elastic ship model;and the experimental results are compared so as to analyze the effects of elastic deformation on the motion and the wave loads respectively.Numerical results for the motion and wave loads are obtained using both the linear and the nonlinear hydroelastic theory,and they are compared with the experimental ones in order to investigate the their applicability when applied to the calculation of wave loads on large ships.It is found that the motion of large ships can be well estimated by both theories,while the wave load is more accurately predicted by the nonlinear hyroelastic theory.In addition,a number of recommendations are also included in thesis for use of the theory in practice.