Cyclic Fatigue Testing of Surface Mooring Hardware for the Arabian Sea MixedLayer Dynamics Experiment

摘要

The Arabian Sea is strongly forced by monsoon winds. Concerns about all in-linemooring components and their fatigue endurance dictated the need for an independent series of cyclic fatigue tests. The components tested included shackles of various sizes and configurations, wire rope, instrument cages, chain, and a variety of interconnecting links such as weldless sling links and end links. The results of the cyclic fatigue tests conducted in support of the Arabian Sea surface mooring design effort are presented in this report. Recommendations are made with regard to all in-line components for surface moorings where dynamic conditions might be encountered for extended periods. The fatigue test results from shackles, and sling links were compiled to generate an S/N diagram where the cyclic stress amplitude is plotted versus the number of cycles to failure. In addition the wire rope test results were compiled with historical wire rope data from US Steel to generate a S/N diagram for torque balanced 3 x 19 wire rope. These results can be used in conjunction with future design efforts. (MM).