Three-dimensional Modeling And FEM Analysis Of Large Wind Turbine Blades

Wind turbine blade is the main component of wind turbine to receive wind energy.As the capacity of wind turbine assembly machines increases,the scale of the blades also increases.Therefore,the higher requirements are imposed on the mode,strength and buckling stability of wind turbine blades.In this dissertation,the modal,strength and buckling stability of a 1.5MW composite wind turbine blade are studied,and the analysis results are summarized and explored.The general rules of blade characteristics are obtained,which provide a reference for blade design,manufacture and failure prevention in advance.The main research contents of this dissertation are as follows:(1)The finite element model of wind turbine blade is built.The coordinate transformation formula is used to transform the original airfoil coordinates into threedimensional space coordinates of the blade section,and the three-dimensional geometric model of the blade is generated by Solidworks;The blade geometric model is imported into Abaqus,and the material parameters are set.According to the blade laying theory,the blade is divided into sections and zones to make the model closer to the actual laying condition of the blade.The blade finite element model is generated by meshing.(2)Wind power blade is subjected to modal analysis.Modal analysis of wind turbine blade finite element model is carried out based on Abaqus.The modal analysis obtains the modes and natural frequency from first to sixth,which is close to the measured value of the actual blade,the rationality of the blade finite element model is verified.Compared with the rotating frequency of the wind rotor,it is found that the natural frequency of the blade is far away from the rotating frequency of the wind rotor,and resonance does not occur.(3)Wind power blade is subjected to static analysis.Static analysis of wind turbine blade finite element model is carried out based on Abaqus.The static analysis obtained the stress distribution of the blade at the ultimate wind speed of 50m/s.It is found that the maximum stress of blade mainly distributes from one-third to two-thirds of the blade root,and the main girder and web are the main bearing structures.The most dangerous section of the blade is one third from the tip of the blade.At the same time,the strength and stiffness of the blade are capable of the design requirements.(4)Wind power blade is subjected to buckling analysis.Buckling analysis of the wind turbine blade finite element model is carried out based on Abaqus.It can be seen that the position where the blade is prone to buckling instability is the cavity at the trailing edge of the blade 6m~10m(the area near the maximum chord length of blade)away from the blade root.The buckling factor of the first six steps of the blade is greater than 1.The buckling load of the blade is greater than the actual load,and the buckling stability of the blade is verified to meet the required foot buckling strength requirement.It is verified that the buckling stability of the blade meets the requirement of the buckling strength.