Collision-Damage Analysis of a Floating Offshore Wind Turbine Considering Ship-Collision Risk

Abstract

Tensile strength (MPa)  Yield strength (MPa)   True stress (MPa)   True yield strength (MPa)    True tensile strength (MPa)   True hardening start stress (MPa)   Dynamic yield stress (MPa)   Dynamic tensile stress (MPa)   Tensile strain   Yield strain   True strain   True yield strain    True tensile strain   True hardening start stain   Strain rate (s-1) IntroductionOffshore wind turbines offer advantages such as securing large installation space and abundant wind resources compared with onshore ones. However, complex risk factors arise from the sea. Among them, ultimate limit states (ULS), such as typhoons, are considered in the design phase of offshore wind turbines, whereas the accidental limit state (ALS), which may occur during the operating period, is not sufficiently considered. The ALS must be considered in the design phase because collision accidents with ships may occur during the operation of marine structures. Although the occurrence frequency is low, the risk of such accidents is high.In 2020, the fixed offshore wind turbine structure of the Borkum Rifgrund wind farm in Germany collided with a 26-m-long high-speed vessel (Renews, 2020). In 2021, a jack-up vessel mobilized for the installation of a wind farm in the waters of Huizhou City, China collided with a substructure (BBN, 2021). In 2022, the monopile substructure of a fixed offshore wind farm in the Netherlands North Sea collided with the bulk carrier "Julietta D," and the installed substructure was dismantled (Durakovik, 2022). In the Netherlands' Hallandse Kust Zuid offshore wind farm, a cargo ship collided with a