| In response to the optimization needs of the transition section design for ultra-large capacity wind turbine foundations in deep sea areas, this paper constructs a model of the slanted box-girder transition section for a 4-pile jacket foundation of an 8.3 MW wind turbine using ANSYS software. Systematic structural static and fatigue analyses are conducted. The research results indicate that the overall fatigue damage level in the transition section is relatively low. However, localized fatigue damage exceeds acceptable limits at the welding points between the box girder and the main shaft, as well as at the welding points between the box girder and the main legs. To address this issue, specific design and application recommendations are proposed: Firstly, during the design phase, local thickening should be applied to the junction area between the main shaft and the top plate of the box girder, or curved elbow plates should be arranged at specified intervals both inside and outside this area to enhance structural strength and stress dispersion capabilities. Secondly, it is essential to ensure smooth transitions in component shapes, avoid sharp edges and abrupt cross-sectional changes, and grind all sharp junctions in the structure to reduce stress concentration. Finally, it is recommended to arrange vertical supports at specified intervals on the surface of the box girder's side plates to improve their overall stiffness and stability, preventing buckling phenomena. The implementation of these measures will help enhance the design quality and operational reliability of the transition section for deep sea wind turbine jacket foundations, providing strong support for the development of deep sea wind farms. |
