Fatigue Analysis of Nylon and Polyester Rope

Many offshore floating wind structures are in development for installation in relatively shallow-water locations where wave motions will cause high amplitude load cycles on the mooring system. In order to reduce peak tensions on hardware and the support structure, engineers and vessel designers are considering the use of mooring lines of compliant

materials, such as nylon or polyester. Several research efforts have conducted laboratory tests to quantify the long-term fatigue performance of polyester and nylon ropes. In addition, examples of field experience utilizing polyester and nylon rope are indicative of the rope’s performance in highly active service. A simple log-log analysis method of data

interpretation is challenged in this paper. A more traditional semi-log analysis is considered as well as a modified log-log analysis with consideration of the influence of mean load locking.

Author(s): E.Huntley, M.Huntley