Ship motions and sea loads

TLDR

A new strip theory is introduced to predict heave, pitch, sway, roll, yaw motions and the associated wave‑induced vertical and horizontal shear forces, bending moments, and torsional moments for a ship advancing at constant speed with arbitrary heading in regular waves. The theory is implemented in a computer program that employs accurate close‑fit section representation to compute the motions and loads. Computed values agree satisfactorily with experimental data, especially for heave, pitch, vertical loads, and coupled sway‑roll motions in beam waves, and horizontal loads in oblique waves, indicating the theory’s reliability.

Abstract

A new strip theory is presented for predicting heave, pitch, sway, roll, and yaw motions as well as wave-induced vertical and horizontal shear forces, bending moments, and torsional moments for a ship advancing at constant speed with arbitrary heading in regular waves. A computer program based on this theory and with accurate close-fit section representation has been developed. Comparisons between computed values and experimental data show satisfactory agreement in general. In particular, very good agreement is shown for the heave and pitch motions and the vertical loads. Accurate results are also obtained for the coupled sway-roll motions in beam waves. Although comparisons are not yet available for the sway-roll-yaw motions in oblique waves, the satisfactory agreement shown for the horizontal loads in oblique waves suggests that the theory may also predict the horizontal motions quite well.