Analysis of probabilistic fatigue damage of mooring system for offshore fish cage considering long-term stochastic wave conditions

This study deals with the probability distribution of fatigue damage of the mooring system for offshore fish cage considering the uncertainty of long-term wave conditions. A set of numerical simulations for offshore fish cage are performed to predict the fatigue damage of the mooring system. Through a virtual stochastic process model, the probability density function of the long-term fatigue damage of the mooring system is achieved by the generalized probability density evolution method, and the failure probability of the mooring system is predicted. The results demonstrate that the generalized probability density evolution method can effectively provide the fatigue damage distribution from the stochastic point of view. And the calibration of the engineering-based fatigue design factor of the current regulation can be conducted through the fatigue reliability analysis considering the uncertainty of the long-term wave conditions. This study provides a new understanding of the long-term fatigue damage distribution.