Wave Response And Structural Strength Of Truss Floating Wind Turbine

In China,the reserves of wind resources are huge and the development of onshore wind resources is saturated.Offshore wind power has a lot of advantages,such as high speed of wind,wind power generation stability and longer time of annual generation,thus it will become the main direction of wind energy development in the future,however,the exploitation and utilization of offshore wind resources are not perfect.The floating offshore wind turbines supporting structure is an important research direction of offshore wind power which containing new base supporting structure proposal,the dynamics response of the base structure under the wind or wave load and the influence of second-order wave force on base structure of wind turbine.Based on the development direction of the industry and the requirements of project,this paper propose the basic structure form of Truss Floating Wind Turbine,and the main load of floating wind turbine is analyzed and estimated.The wind load and wave load are used as the external load of the static analysis of the wind turbine base,and the strength analysis of the truss floating wind turbine structure is carried out.The influence of second-order wave force on the structure response of floating offshore wind turbines is studied by numerical simulation and scale experiment,and the influence of different wind turbine structures on structural response is studied.The main contents and research results are as follows:The analysis of the external load of the floating wind turbin e shows that the wave load of the wind turbine base structure is much larger than the wind load,and the wind load of the blade is greater than the wind load of the tower.The results of strength analysis of different wind turbine base structure show that the addition of truss structure can help to reduce the maximum Mises equivalent stress and maximum equivalent strain,and truss structure can prolong the service life of the wind turbine.Numerical simulation of frequency domain and time domain is carried out by using ANSYS-AQWA.The conclusion is that the added mass of surge,sway,heave and yaw were increased while the added mass of pitch and roll were decreased.By comparing the response results of the same wind turbine,it is found that the second-order has a great influence on sway,pitch,roll and yaw but has little effect on surge and heave.Through the analysis of different model response results,it is concluded that the truss floating wind turbine is more sensitive to second-order wave force,and has less response in surge and sway but more response in pitch,roll and yaw.A 1:80 scale model was designed for the numerical simulation result model,then a scale model test was carried out in Wind Tunnel and Water Flume HIT.The comparison between the results of stimulation response and scale model test response show that most results of surge response are consistent with sway response.For the non-anastomosed situation,it is considered that the dynamic response of the wind turbine structure is not negligible.