Optimization Design And Structure Analysis Of Large-scale Wind Turbine Blades

With comprehensive consideration of aerodynamic design, load evaluation, material propertiesand structure design, an improved NSGA-II optimization algorithm is given in this paper to obtainthe optimal solution set for large-size wind turbine blades. Using this method and taking themaximum power and minimum mass as the optimization objectives, a1.5MW wind turbine blade isdesigned and its structural results are then checked and analyzed in detail.According to the rectangular element and the trapezoidal element methods, an engineeringapproach for the calculations of the normal stress and shear stress on wind turbine blade is derivedusing the beam theory and multi-closed chamber profile shear flow calculation. Given the geometry,material, load and section safety coefficient, the blade structural layout is efficiently optimized to getsection geometrical properties and static strength under the ultimate load including the distribution ofline quality, stiffness, normal stress and shear flow. A finite element model of the blade section isestablished to validate the engineering calculation method by ANSYS software. Based on the sectiongeometrical properties, a displacement calculation method and modal analysis method are proposedusing beam theory, for completeness of the wind turbine blade structural check.A program is also presented in APDL language, which can precisely generate the finite elementmodel of blade mentioned above. To prove the reliability of the optimization, the static strength of thematerial, displacement, natural frequency and stability of the blade under the ultimate load areanalyzed. Based on the three-dimensional finite element calculation results, the two-dimensionalengineering algorithm is validated with satisfactory results.