Failure analysis of floating offshore wind turbine technologies

The technology of Floating Offshore Wind Turbines (FOWTs) is still at an early development stage and its reliability is not yet fully tested and proven. This study aims to perform a quantitative failure analysis on a FOWT technology with a spar-type platform and three catenary mooring lines. The analysis is built on two well-established reliability engineering methodologies, namely, Fault Tree Analysis (FTA) and Failure Mode and Effects Analysis (FMEA). The most critical components are identified and ranked according to their failure probability and the severity of the possible consequences. The results show a good agreement between two methods with regard to failure criticality rankings. However, some diversities between the results are also observed which are attributed to the difference between FTA and FMEA methods, as the former incorporates the causes of multiple failure modes whereas the latter is mainly used for single failure analysis.