Linear and nonlinear hull-girder loads on a modern 6500 TEU containership advancing in waves are calculated using a 3D timedomain Rankine panel method. The numerical code used is based on weakly-nonlinear scheme including nonlinear Froude-Krylov and restoring forces. Main focus of this study is to validate the nonlinear numerical code for industrial use through the comparison of the linear and nonlinear characteristics of wave-induced loads on a modern 6500 TEU containership with experiments. The compared responses include 6-DOF motions, vertical shear forces, vertical bending moments, torsion moments, horizontal shear forces and horizontal bending moments at high waves, as well as linear transfer functions.
The main objective of this comparative study is the validation of a nonlinear 3D time-domain seakeeping code based on Rankine panel method. In general, the structural evaluation of designed ship is based on the specified rule values. However, those design wave loads are thought to be insufficient for large, fast and novel ships which are frequently introduced to the market at the present time. Consequently, recent interest in structural safety assessment for such modern ships has fueled the direct application of wave loads to structural FE (Finite Element) analysis. Hence, a 3D nonlinear time-domain seakeeping code, WISH (Kim, K.H. et al. 2008; Kim, Y. et al., 2008), has been developed in a joint industry project, WISH-JIP. Experimental tests with ship models carried out in seakeeping basin are used to predict the performance of new design of ships and to obtain data to validate numerical codes. The experimental investigations and validation of the numerical tools are also important part of the research issues. Verification, validation and accreditation are essential to the process for newly developed computer code to make successful debut in the support of design (Beak and Read, 2001).