Experimental Investigation on Dynamic Stiffness of Damaged Synthetic Fiber Ropes for Deepwater Moorings

Abstract

To understand the evolution of dynamic stiffness of damaged synthetic fiber mooring ropes, experimental investigations of polyester and high modulus polyethylene (HMPE) ropes are systematically performed utilizing a specially designed experimental system. An experimental procedure is proposed and test results show that the dynamic stiffness increases with increasing mean load and loading cycles, while decreases with increasing strain amplitude and damage level. The similarity criterion of dynamic stiffness is derived from the dimensional analysis for damaged ropes and verified by experiments. An empirical expression that accounts for the damage, mean load, strain amplitude, and loading cycles is proposed to describe the damage effect upon dynamic stiffness of synthetic fiber mooring ropes.