Abstract
Nowadays, there is a search for renewable energy sources that are more attractive in terms of cost-effectiveness. Thus, the wind has been considered as one of these sources. Therefore, wind turbines have been installed. As a consequence, it is necessary to develop technologies, mathematical models, capable of analyzing the behavior of the structure in operational and accidental conditions. The present research is mainly focused on the structural design and analysis of a floating offshore wind turbine foundation, which supports the tower of the turbine. Furthermore, the work includes the behavior analysis of the platform in four different conditions: Intact, one broken line, two broken lines and three broken lines. For each condition, it was evaluated the effective tension of the mooring lines extremities. Thus, it was possible to check the mooring lines MBL (Minimum Breaking Load), and finally, it was checked too, the stress levels at the base of the tower. To fulfill the established objective, initially, the shape of the platform was idealized, the thickness of the platform plates were designed, the material plates were defined, etc. After, motion analysis was carried out using the OrcaFlex and AQWA softwares. Subsequently, a mooring system was designed, thereby, for the proposed case study, a global numerical analysis of the system was performed, using the OrcaFlex software, imposing the environmental loads. Finally, the results in terms of the platform motions, mooring lines effective tension and stress level at the base of the tower were evaluated. Therefore, the intact and accidental condition of the platform were analyzed for the wind turbine supposedly installed in the region of Rio de Janeiro, Brazil.
