考虑桩土相互作用的海上风机整机一体化动力疲劳分析OA

The service environment of offshore wind turbines is complex.Traditional design methods model the superstructure and the foundation separately,failing to account for the multi-field coupling effects among wind-wave-current,turbine control,structure,foundation,and seabed,leading to inaccurate load and fatigue assessment.For refined analysis,this study secondarily developed a self-proposed dynamic p-y+M-θ monopile model into the load calculation software FAST,establishing an integrated platform for whole-machine coupled analysis of offshore wind turbines.Based on this platform,the effects of four soil-structure interaction(SSI)models-fixed base,API p-y,and refined p-y+M-θ models(with/without soil damping)-on the load response and monopile fatigue life of an NREL 5MW reference turbine were systematically compared.The results show that the SSI model significantly affects the natural frequency and load oscillation amplitude of the turbine.Compared to the most realistic p-y+M-θ model(with damping),the traditional fixed-base model underestimates the load cycle amplitude by up to 60%on average under parked conditions,while the API p-y model overestimates it by 33%on average.Neglecting soil damping overestimates the fatigue load cycle amplitude by 6%-22%.Regarding fatigue life,using the API p-y model underestimates the monopile fatigue life by 42%,and ignoring soil damping causes an additional underestimation of 24%.This research highlights the importance of refined consideration of pile-soil stiffness and damping for the safe and economical design of offshore wind turbines.