Extreme Value Analysis of Ship Roll Motion With Consideration of Ice Accumulation

Ice accumulation poses a significant threat to ship stability, potentially leading to capsizing if the roll angle surpasses a certain threshold. Investigating the impact of ice accumulation on the extreme roll angle is crucial for the safety and stability of ship sailing in Arctic regions. This article presents a study that aims to evaluate the effects of ice accumulation on ship stability in waves. Specifically, the standard ship model CEHIPAR 2792 is selected, and the dead ship condition is considered. Calculation of the roll damping coefficients via CFD method has been verified with the experimental data. Then, single-degree-of-freedom (SDOF) models for roll motions with and without ice accumulation are established to calculate the roll response in random seas. The influence of ice accumulation on the roll damping term as well as on the restoring term are incorporated into the SDOF model. Finally, extreme value analysis is executed to evaluate the influence of ice accumulation on the roll response and ship stability in waves. This Research has shown that predicting extreme values of roll motion response is a more effective approach in capturing the impact of ice accretion on the stability of vessels in waves, surpassing conventional measures such as restoring lever arm. This methodology enables an enhanced assessment of the hazards associated with icing conditions.