Prediction of Extreme Ship Motions in Irregular Waves

The occurrence of indirectly excited large amplitude roll motions of ships is investigated under the influence of a time-varying righting lever curve in waves. In order to account for the irregular character of ocean waves appropriately, the ship motions are described within the framework of nonlinear dynamics and stochastic process theory. The analysis of roll motions in regular waves provides a qualitative understanding of the occurrence of unpredictable large amplitude roll motions as observed in ocean waves. However, quantitative information on the rolling behavior in irregular waves may be retrieved only from a probabilistic analysis. (© 2005 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)