Approximation of capsize probability using a Roll Excedance (RE) probability with a threshold chosen in roll phase plane

OCEAN ENGINEERING

卷:187

Article

Mace, Romain¹  Billard, Jean-Yves²  Lannel, Guillaume¹  Leguen, Jean-Francois¹ 

[1] DGA Hydrodynam, Val De Reuil, France

[2] Inst Carnot ARTS, IRENAV, Paris, France

关键词: Capsize probability;    Monte-carlo;    Roll exceedance;    Attraction basin;   

DOI  :  10.1016/j.oceaneng.2019.06.003

来源: Elsevier

【 摘 要 】

The paper investigates the correlation of capsizing and non-capsizing trajectories in an attempt to identify a relevant parameter for capsize probability assessment The probability of capsize of decommissioned French naval ships, a Frigate and helicopter carrier Jeanne D'Arc, have been determined by a Monte Carlo procedure. Despite the computation cases are limited to two ships and two sea states, data sets generated tend to show in trajectory phase plane a convergence of the envelopes of non-capsized trajectories and of capsizing cycles. The presumed convergence of the envelopes would indicate a correlation between capsized and non-capsized trajectories. This suggest a faster and more cost effective probability assessment method is conceivable, using a reduced number of computations and set of data compared to Monte Carlo Method. Statistical analysis of capsizing cycles shows a normal law can approximate properly the roll rates distribution before capsize, particularly the roll rate at zero crossing and the roll rate extrema after zero crossing. However, partial match is obtained between these criteria associated to the probability obtained from Monte-Carlo method and the curve Of probability of roll rate exceedance obtained with non-capsizing cycles. Additional computations, that widen the scope of ships and sea states, are in progress.

【 授权许可】

Free