Dynamic analysis of lift-off operation of offshore wind turbine jacket foundation from the transportation barge
Mingsheng Chen, Guibo Yuan, Bin Li, Chun Bao Li, Mingjun Ouyang, Lin Li, Wei Shi, Zhaolong Han, Wei Zhang, Ziwen Chen
Abstract
The lift-off operation of the offshore wind turbine jacket foundation from a barge is investigated in this study. Firstly, the hydrodynamic analysis of the two ships is carried out via AQWA, considering the series configuration and L-shaped configuration. The damping lid method is introduced to address viscous correction and validated by a frequency-time-domain validation. The damping lid factor for the two configurations are set to be 0.02 and 0.04. The time-domain simulation of multi-body lifting system, including lifting wires, slings, and deck fenders, are then carried out. In the nonstationary time-domain simulation, the sensitivity of wave direction, vessel configuration and deck fender stiffness are investigated, indicating that the most critical stage during the lift-off operation corresponds to when about 70% weight of the jacket is lifted by the heavy-lift vessel. The series configuration under head sea in 70% load transfer stage is chosen for subsequent steady-state simulations. Extreme value analysis is carried out based on the Gumbel distribution . The allowable sea states are then evaluated. The operability is obtained by using the 20-year hindcast wave data of three certain sites off Guangdong, Fujian and Zhejiang coast, which are 60%, 55% and 65%, respectively.