Comparison of numerical and experimental results of nonlinear wave-induced vertical ship motions and loads

摘要

A nonlinear time-domain procedure is presented which is used to calculate the vertical responses of a container ship advancing in head waves. The method assumes linear radiation forces represented by time convolution of memory functions, infinite frequency added masses, and radiation re- storing coefficients. The nonlinear hydrostatic restoring and Froude-Krilov forces are computed exactly over the instanta- neous wetted surface of the ship's hull. Forces due to green water on deck are calculated using the momentum method. Nonlinear effects are identified on different vertical ship re- sponses, namely on the heave and pitch motions, the vertical accelerations, and the vertical bending moment.