Abstract
This paper discusses an onsite installation method that involves the direct installation of a wind turbine at an offshore operating site. Since a fully assembled wind turbine is lifted and installed on a spar foundation at the operational site, complex responses are expected due to the multibody system of the installation vessel, the lifted wind turbine, and the spar foundation. To verify the reliability of the numerical results of the proposed alternative installation method and to gain a better understanding of the system dynamics, the installation system was modeled using SIMO and OrcaFlex, and the numerical results were compared. The comparative study was conducted in the following steps: 1) eigenvalue/modal analysis, 2) RAO verification and comparison, and 3) dynamic analysis and comparison. The results obtained in this study can be utilized in the design system components such as installation vessels, floating foundations, mooring systems, mechanical dampers, lifting devices, and control systems.
