Shengjie Rui, Zefeng Zhou, Hans Petter Jostad, Erin E. Bachynski, Svein Sævik, Xiaoming Ran, Liang Wang, Zhen Guo
• Conducted dynamic analyses of the VolturnUS-S floating platform supporting the IEA 15 MW wind turbine. • Evaluated the impact of embedded mooring chains on the structural response of floating wind turbines under both operational and parked conditions. • Analyzed and compared mooring line, floater, and turbine responses with detailed modeling of chain–seabed interaction. • Investigated mooring line configurations and tension variations under dynamic loading scenarios. Traditional integrated analyses of floating wind turbines (FWTs) commonly neglect the embedment of the mooring line in the seabed, which may increase uncertainties in mooring system design. A macro-model for chain-seabed interaction was previously introduced in the static mooring analyses for FWTs. In this study, dynamic analyses of the VolturnUS-S floater supporting the IEA 15MW FWT are conducted using a macro-model of chain-seabed interaction in SIMA. Five typical cases are considered to investigate the dynamic responses of FWTs under both operational and parked conditions, focusing on the influence of the embedded line and seabed friction. The mooring line responses, floater responses, and turbine responses are analyzed and compared. Finally, mooring line configuration and tension variation are analyzed and discussed. The embedded line notably impacts mooring line responses, primarily by reducing the load acting on the anchor padeye. While seabed friction has minimal effect on the maximum fairlead tension, it has a significant influence on the padeye tension. Additionally, extreme tension drives the embedded lines toward the floaters. When the tension is subsequently reduced, the lying chain moves back toward the padeye, and this reverse displacement induces reverse seabed friction. This study provides an insight into the embedded line influence on the dynamic responses of FWTs.