Motion response analysis of FPSO with single point mooring system based on fully nonlinear method

The mooring system of FPSO has characteristics of large curvature ratio and high deflection, and the existing hydrodynamic load calculation methods ignore some nonlinear wave factors. In this paper, the mooring system analysis was achieved by using the slender rod theory and finite element method. Based on the boundary element method, the particular auxiliary function and mixed Lagrangian-Euler method were employed to solve the simultaneous hydrodynamic force at each time step. Finally, a hull and mooring coupled motion forecast method was established by integrating the forward two methods and a self-programming code was developed. The model is verified by comparing the numerical results of a FPSO under RAO conditions with experiment data.