Prediction of Vertical-Plane Wave Loading and Ship Responses in High Seas

The non-linearities in wave- and slamming-induced rigid-body motions and structural responses of ships such as heave, pitch and vertical bending moments are consistently investigated based on a rational time-domain strip method. A hydrodynamic model for predicting sectional green water force is also outlined for the investigation of the effect of green watrer oads on the globalhull girder bending moment. The computational results based on the non-linear time-domain strip theory are compared with those based on the fully non-linear 3-D panel method SWAN-DNW and other published results.From the rather extensive computations and comparisons, it is found that non-linear effects are significant in head and bow waes in the motion-wave resonant region for both heave and pitch motions, bow accelerations and vertical bending moments for two container ships considered, whereas not significant for a VLCC. The non-linearities in motions and structural loads of conventional monohull ships seem well predicted by the present non-linear strip theory.