Study On Structure And Properties Of MW Wind Turbine Blade

As the problem of environmental pollution has become more and more serious,wind energy as a kind of renewable energy which will not produce any pollution is highly valued.In this thesis,the object of study is a wind turbine blade,the finite element method is used to study the dynamic and fatigue characteristics of the wind turbine blade by using three modules:mode,fluid solid coupling and fatigue analysis.Firstly,in the study of dynamic characteristics of structure,2MW wind turbine blade based on the aerodynamics theory is established,the finite model is established in the finite element software.Analysis of dynamic characteristics of wind turbine blades is considered by ANSYS WORKBENCH.For wind turbine blades working in the different rotary speed conditions,researches the influence of dynamic stiffness caused by blade rotation.The natural frequency of blades in different rotation speeds is calculated.It focuses on the structural dynamic characteristics of different structure of the wind turbine blade in complex working conditions,this chapter provides a reference for design and optimization of the structure of wind turbine blade.Secondly,because of the complexity of blades surface and load distribution are researched.By the fluid-solid coupling module,it mainly compares the aerodynamic stress distribution of blade load,centrifugal force and gravity force coupling analysis,and the stress distribution characteristics;by extracting the key position of the stress region.It analyses the stress variation of the blade.According to the calculation results,the strength of the blade is checked,which provides a basis for the optimum design of the blade.Finally,this study uses the finite element numerical analysis method,the fatigue safety coefficient is obtained under constant wind load,equivalent cyclic stress level under equivalent fatigue load spectrum under symmetrical cyclic fatigue,and through the analysis of fatigue characteristic analysis module of finite element model,which provides a reference for the study on the fatigue properties of wind turbine blades.The equivalent stress of the working cycle is equivalent to the fatigue load spectrum,and the fatigue characteristic of the finite element model is analyzed by the fatigue analysis module,this chapter provides a reference for the study of the fatigue behavior of the wind turbine blade.