Dynamics of mooring cables in random seas

The dynamic analysis of a catenary mooring cable due to random motion of an offshore platform is performed in the frequency domain. The nonlinear fluid-drag force is linearized using the statistical linearization technique. A previously developed numerical procedure based on converting a boundary value problem to an equivalent set of initial value problems is utilized to solve the problem, which avoids the need for modal analysis. The method is found to be versatile for the determination of spatially varying drag and the analysis of composite cables in a unified manner. The influence of current on drag damping has also been investigated. The effect of seabed friction damping has also been incorporated in the linearized analysis