Evaluating Mooring Line Test Procedures through the Application of a Round Robin Test Approach

Abstract

Innovation in materials and test protocols, as well as physical and numerical investigations, is required to address the technical challenges arising due to the novel application of components from conventional industries to the marine renewable energy (MRE) industry. Synthetic fibre ropes, widely used for offshore station-keeping, have potential application in the MRE industry to reduce peak mooring line loads. This paper presents the results of a physical characterisation study of a novel hybrid polyester-polyolefin rope for MRE mooring applications through a round robin testing (RRT) approach at two test facilities. The RRT was performed using standard guidelines for offshore mooring lines and the results are verified through the numerical modelling of the rope tensile behaviour. The physical testing provides quantifiable margins for the strength and stiffness properties of the hybrid rope, increases confidence in the test protocols and assesses facility-specific influences on test outcomes. The results indicate that the adopted guidance is suitable for rope testing in mooring applications and there is good agreement between stiffness characterisation at both facilities. Additionally, the numerical model provides a satisfactory prediction of the rope tensile behaviour and it can be used for further parametric studies.

Mechanisms of Strain-Induced Interfacial Strengthening of Wet-Spun Filaments

“…In units typical of textile materials, Figure S16 refers to a specific strength of 0.65 N tex –1 for DA-CMC/CNT@100, exceeding the mechanical performance of nanocellulose fibers (∼0.29 N tex –1 ) and polyester-polyolefin fiber yarns (0.59 N tex –1 ). 31 , 52 …”

“…This strength improvement can be ascribed to the formation of more isotropic structures affecting the axial properties and enhancing the strength between neighboring building blocks as a consequence of an ordered packing. In units typical of textile materials, Figure S16 refers to a specific strength of 0.65 N tex –1 for DA-CMC/CNT@100, exceeding the mechanical performance of nanocellulose fibers (∼0.29 N tex –1 ) and polyester-polyolefin fiber yarns (0.59 N tex –1 ). , …”

Standardising Marine Renewable Energy Testing: Gap Analysis and Recommendations for Development of Standards

“…The RR programme on mooring testing [73] found that ISO guidance on moorings [74] is suitable for ORE testing, with a recommendation that higher-frequency loading be incorporated.…”

Numerical Modelling for Synthetic Fibre Mooring Lines Taking Elongation and Contraction into Account

“…Synthetic mooring lines usually have relatively large elongations, even when made of novel types of rope [25,43]. Since Poisson's ratio for synthetic ropes can be assumed as 0.5 [44], a significant reduction of the outer rope diameter can be expected.…”