OPTIMIZATION DESIGN OF THE JACKET SUPPORT STRUCTURE FOR OFFSHORE WIND TURBINE USING GOLDEN-SINE DYNAMIC MARINE PREDATOR ALGORITHM

Jacket support structure is the main support form for bottom fixed offshore wind turbine. Weight optimization is critical importance due to the substantial volume of material used in the components of jacket support structures. A metaheuristic algorithm is a powerful tool that allows many parameters in a structural optimization design to be considered simultaneously. As a nature-inspired metaheuristic algorithm, Golden-Sine dynamic marine predator algorithm (GDMPA) has been proved to be competitive in multi-modal and high-dimension optimization problems. In this study, a type of offshore wind turbine composed of the Offshore Code Comparison Collaboration Continuation (OC4) reference jacket structure and the NREL 5 MW baseline turbine was optimized using GDMPA. The forces applied to the structure are realistic ensuring that the simulations are accurate and realistic. The inner problem which consists of member sizing is solved using a robust and efficient GDMPA. An innovative jacket structure with ultimate strength, stiffness, stability, and natural frequency constraints was optimized. Moreover, ultimate limit state analysis, eigen analysis and fatigue analysis are used to evaluate the optimized structure. The results indicate that the proposed optimization method is an effective way to reduce the weight and stress concentration. The final design is a low mass jacket support structure that fully complies with offshore structural standard requirements for all design limit states, while meeting the fatigue life of the welding points, thus being best suited for long operating life.