Reliability analysis of ship time domain motion response based on fractional order moment maximum entropy method

Addressing the ship motion response under stochastic irregular waves and accounting for the uncertainty of these waves, a time-domain numerical simulation was conducted on the S175 container ship utilizing the three-dimensional time-domain potential flow theory to develop a model of ship motion response. The extremum method was applied to convert the time-varying problem of motion response into a time-invariant problem, thereby establishing a reliability analysis model for ship motion response under irregular wave conditions. Subsequently, the extremal distribution of the motion response was calculated using the fractional moment maximum entropy method to derive the probability density function. By assessing the extremal distribution of motion response under specific sea state conditions, a new method for analysing ship motion response was proposed. This approach can provide a relatively accurate estimation of the probability of danger associated with ship motion response.