Re-evaluation of Mooring System Durability for Renewal and Reuse of Floating Offshore Structures

Abstract

Floating offshore structures in general and floating wind turbines in special have flexible exploitation capacity in different sea conditions. Moreover, they can be reused. The mooring system is one of the main parts that need to be considered for re-evaluation when reusing floating structures in new operating conditions or extension of exploitation period. Therefore, in order to response to the re-licensing requirements of floating structures, it is important to re-evaluate their mooring systems. During exploitation, due to the cumulative damage caused by several factors such as corrosion, abrasion, etc., it is possible that the calculated safety factors of deteriorated mooring systems could be lower than the allowable value. In that case, the reversed design problem will need to be studied in order to predict the critical environmental conditions where the mooring system can still be in-use. Based on that, we can select the appropriate technical parameters where the structure is still allowed to continue operating. The objectives of this study are to investigate the theoretical basis and fundamental steps for re-evaluating the durability of mooring lines of floating offshore structures. Indeed, due to the lack of standardization method and analysis procedure, comprehensive research seems crucial before practical application.