Study on the Calculation Method for the Dynamic Behavior of Polyester Rope

Abstract

The dynamic stiffness of polyester rope presents a complex mechanical performance, and the search for an appropriate calculation method to simulate this property is important. Distorted simulation results eventually yield inaccurate line tension and vessel offset predictions, with the inaccuracy of vessel offset being particularly large. This paper proposes a flexible calculation method for the dynamic behavior of polyester rope based on the dynamic stiffness model. A real-time varying stiffness model of polyester rope is employed to simulate tension response through rope strain monitoring. Consequently, a simulation program is developed, and related case studies are conducted to explore the differences between the proposed method and analytical procedure of the DNV standard. Orcaflex is used to simulate the results of the latter procedure for comparison. Results show the convenience and straightforwardness of the procedure in the selection of an approximate dynamic stiffness model for polyester rope, which leads to an engineering-oriented approach. However, the proposed method is related to line property, which can directly reflect the dynamic behavior of polyester rope. Thus, a flexible calculation method may provide a reference for the simulation of the dynamic response of polyester mooring systems.

Keywords

Polyester rope / Dynamic stiffness model / Mean tension / Minimum breaking strength / Case studies

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