Experimental Study on the Dynamic Stiffness of Full-Scale Polyester Ropes With Damage Levels

Abstract To understand the evolution characteristics of the dynamic stiffness of full-scale polyester mooring ropes with damage, series of experimental tests are conducted using a specially designed large-tonnage rope testing system. An experimental procedure for testing the dynamic stiffness of full-scale fiber ropes with damage is proposed. The damage level of the fiber rope was induced by cutting the rope strands. Experimental results indicate that for polyester ropes with a certain level of damage, the dynamic stiffness increases with the increase in average tension, but decreases as the increase of the tension amplitude, loading period, and damage levels. Based on the experimental results, an empirical expression was proposed to comprehensively consider the rope damage level, average tension, tension amplitude, and load periods on the dynamic stiffness of full-scale polyester mooring ropes, thereby contributing to the service safety of fiber ropes in offshore oil and gas engineering.