2025S-OS2-2 Calculation method of second-order distribution of capsizing probability in beam sea

抄録

The assessment of a ship capsizing risk in beam sea is one of the most important indicators for measuring a vessel's basic performance. The authors have proposed a method to qualitatively and quantitatively calculate the response and capsizing probability of systems with nonlinearities in roll damping and restoring moment. For example, it is difficult to accurately measure roll damping, one of the parameters governing ship motion, on a real ship. Therefore, it must be estimated by Bayesian inference from time series data, for example. In such cases, the estimated parameters are distributed stochastically and never have definite values. As a result, the response distribution and capsizing risk would also be further stochastically distributed. This is a probability distribution of a probability distribution, which is known as a second-order distribution. In this study, we propose a calculation method to theoretically obtain the second-order distribution of capsizing probability.