A Practical Framework for Efficient Assessment of the Fatigue Damage of Mooring Systems in Non-Gaussian Seas

This paper provides a practical framework for efficient assessment of structural fatigue damage in non-Gaussian seas. The key features of the framework are that the non-Gaussian stochastic wave is generated based on the translation process theory and incorporated into the dynamic analysis model with the help of parametric identification technology. The convolution terms of the radiation and exciting wave force in the dynamic analysis model are represented by the state-space models with constant coefficients, and the computational effort of dynamic analysis and fatigue assessment can be reduced significantly with the framework. A comprehensive investigation of fatigue damage of mooring systems in a non-Gaussian stochastic wave is conducted with a deep-water semi-submersible platform. Numerical results show that the non-Gaussian stochastic wave can accelerate structural fatigue damage significantly, and more attention should be paid to the influence of the nonGaussian stochastic wave on fatigue damage of mooring systems in the design procedure.