Fatigue of polyamide mooring ropes for floating wind turbines

International audienceThis paper describes a study of the fatigue characterization of polyamide mooring ropes for floating wind turbines. Undersome conditions polyester ropes, which are favoured for offshore platform station-keeping, are too stiff for wind turbine moorings, and polyamide may be a suitable alternative. While early studies on fatigue of braided nylon ropes showed very short lifetimes some recent results have indicated that it is possible to significantly enhance lifetime by modifying rope construction and improving fibre coatings [1]. The fatigue results presented here for ropes from a different supplier, confirm thisresult. In order to develop an accelerated evaluation of the fatigue performance,heatbuild-up tests havebeen performed, and promising first results are shown. Finally, the influence of coating is examined by microscopy and yarn-on-yarn tests, in order to improve understanding of the fatigue mechanisms leading to failure