Non-destructive testing of high-tenacity polyester sub-ropes for mooring systems

Deepwater mooring systems used in offshore oil exploitation need increasing performance because mechanical solicitations are always higher. Thus, two polyester sub-ropes were studied in this work, aiming for higher -tenacity materials, SFS5202 and UFS8602. Through non-destructive testing based on quasi-static, dynamic, and cyclic loads applied as a percentage of the Minimum Breaking Strength (MBS), the behavior of the underwire for two polyesters and two braiding steps was evaluated. Good performance was obtained in the test concerning low deformation, suggesting that it is a fiber material with high tenacity and elastic modulus, thus becoming adequate for deeper water oil exploitation. Furthermore, UFS8602 produces a higher normalized stiffness and recovery than SFS5202, likely because of the improvement of braiding pitch and polymeric material.