Assessment of extreme rolling of ships in random seas
International Conference on Offshore Mechanics and Arctic Engineering (OMAE 2014)
Contribution to Conference
The goal of our analysis is to improve intact stability criteria for ships. For this, we develop analytical formulas for mean first passage times of critical roll amplitudes of ships travelling in long crested random seas with an arbitrary wave encounter angle. Starting from a model for coupled heave-pitch-roll motion, we average the fast oscillatory dynamics of roll over the roll period, which yields equations for drift and diffusion of roll energy. The results are used to calculate the desired mean first passage times. Finally, we apply the proposed theory to a sample ship design.