Based on the theory of impact dynamics, the motion equations for a mooring line-floating body system before and after impact loading are established with consideration of the viscoelastic property of mooring lines. The factors that influence the taut-slack conditions of a mooring system are analyzed through classifying the taut-slack regions, which are defined by non-dimensional ratios of displacement, frequency, and damping of the system. The mooring system of Jip spar platform is analyzed, and the snap tension characteristics of mooring lines are given. The factors that influence the maximum tension in mooring lines, including the mass of the floating body, length of mooring lines, frequency and amplitude of external excitation, and pretension in mooting lines, are also analyzed through computing the dynamic response of system and parametric study. It is shown that the maximum tension increases with the increasing mass of the floating body, external excitation and pretension. Also, it is found that the influence of the non-dimensional ratio of damping increases with the increase of the pretension in mooring lines.
