Analysis of Nonlinear Dynamic Response of Mooring Lines in Deepwater

Nonlinear motion equations of cable is reduced with the assuming of linear constitutive relation, and simplified further according to propagation characters of stress wave. The loading acting on quasi-static cables are analyzed and the detailed expressions are given. The displacement, stress and strain in mooring line in deep water are calculated in this paper, and the nonlinear propagation characters of stress and strain, the motion characters and the effect of drag force reduced by fluid on the dynamic tension in cable are analyzed respectively. The results show that, the stress in cable propagating from exciting end to fixed end and there is a difference in phase. At the same time, the stain in cable different point is also different. At the point with maximum tension, the normal motion is double-period and the tangential motion is quasi-periodic. The tension in cable is effected by tangential and normal drag.