Experimental Investigation of the Platform and Tendon Dynamics of a 16 MW TLP Floating Wind Turbine

This study experimentally investigates the platform motions and tendon tensions of a 16 MW tension leg platform (TLP) floating wind turbine. A 1:85 hybrid model was tested under free-decay, regular-wave, irregular-wave, and combined wind–wave conditions. Under irregular waves, increasing the peak period enhanced the surge and heave dynamic responses but reduced the tension fluctuations of the selected tendons, whereas increasing the significant wave height enhanced both platform and tendon dynamic responses. Combined wind–wave loading introduced mean offsets in surge and pitch and altered the mean tension distribution among the selected tendons. The surge dynamic response remained close to the corresponding wave-only response, whereas the heave dynamic response showed a clear increase under combined wind–wave loading. The mean values of surge and pitch reached their largest measured values at the rated wind speed of 12 m/s, whereas the pitch and tendon dynamic responses became more pronounced at higher wind speeds. Frequency-domain analysis suggests possible coupling between the upwave tendon and platform pitch near the measured pitch natural frequency of approximately 0.249 Hz. Another possible coupling is indicated between the selected lateral tendons and the tower second mode within 2.1–2.2 Hz. The experimental results provide valuable insights into the platform and tendon dynamics of large-capacity TLP floating wind turbines and support their dynamic-response assessment under wave and combined wind–wave loading.