Structural Analysis Of The Composite Wind Blade Using Finite Element Method

Study on the method for structural design and analysis of the composite wind blade is always one of the hot social studies. It is of great significance to promote the effective use of green resources.In this thesis, the work done by the following:1) Came to understand the basic principles of aerodynamic design of the wind blade which includes the basic theories, basic concept and formula for calculating aerodynamic parameters of the wind blade.2) Analyzed the wind blade structure, including its structural and loading forms analysis, its load conditions and the layer placement design.3) Took a 25m long wind blade for example, got the facial coordinate (x,y) of the point on the aerofoil from Profili which is a aerofoil design software, calculated its space coordinates (x' ,y' ,z) in Matlab by the way of coordinate transformation, established its solid model in Pro/E (CAD software), imported the solid model into ANSYS (CAE software) and established its finite element model. The modeling process can offer other analog complicated structures needing precise model a reference.4) Simulated the surface wind pressure of the blade using FLUENT software, exported the coordinates of the discrete point and the corresponding pressure value, got the function relation between the wind pressure and point coordinate in Matlab by means of polynomial curve simulation, loaded the pressure onto the blade finite element model.5) Static analysis: done finite element analysis of the blade structural static strength under two adverse conditions, calculated the displacement, strain and strength ratio of every structure layer, checked its static strength and stiffness according to relevant standards in order to determine whether its strength meet the design requirements or not.6) Stability analysis: done finite element analysis of the blade stability under two adverse conditions, analyzed the safety coefficient and inflexion mode in order to tell whether the blade loses its stability or not and the form of instability.7) Dynamics analysis: done finite element analysis of the blade dynamic characteristics, established the free vibration function, calculated ten frontal natural frequency and its corresponding vibration modes.All work done above mean to look for a new method for wind blade structure characteristic study. So that it can provide a new reference for wind blade design.