Passive control of feather fault offshore wind turbine under combined earthquake wind and wave loads

Earthquakes are a potential hazard for offshore wind turbines (OWTs) located in seismically active regions. In this study, a coupled seismic analysis model for an OWT under earthquake, wind, and wave loads is established, and a typical feather fault caused by damage to electrical devices is modeled. Then, the dynamic characteristics of the feather fault OWT are studied under earthquake conditions. The influences of stochastic winds and waves on the seismic responses are also investigated. The passive control method of multiple tuned mass damper (MTMD) is designed and applied to the feather fault OWT, based on the dominant natural modes of the seismic responses. Further, the applicability and effectiveness of the designed MTMD are evaluated, based on reductions in the responses of the feather fault OWT under earthquakes in the time and frequency domains.