Experimental study on dynamic stress of blades with different materials under wind direction change
In order to understand the stress changes of wind turbine blades with different materials du-ring the process of wind direction change,S-shaped wind turbine blades with wood,glass fiber,and carbon fiber materials were used as the research object.Wind tunnels and dynamic rotating platforms were used to simulate the wind direction changes and experimental methods were used for research.The results show that under the same wind speed and the same tip speed ratios,the stress value at the lea-ding edge of the blade root of carbon fiber blade with larger elastic modulus is much higher than that of glass fiber blades and wood fiber blades.The strain value at the leading edge of the blade root of the glass fiber blade with larger weight is much higher than that of the carbon fiber blades and wood fiber blades.The distribution of root and spreading stress and strain of different materials is different,but the overall trend shows basic decrease from leading edge(0.25C)to trailing edge(0.90C)and from root(0.20R)to tip(0.90R).At the beginning of wind direction changes,the stress and strain values of carbon fiber blades with high stiffness show an obvious downward trend at each measuring point due to their strong resistance to elastic deformation,followed by glass fiber blades and wood blades.The stress and strain values at each measuring point of the three material blades show an inverse S-shaped down-ward curve.Different blade materials can lead to significant differences in tensile or extrusion action and azimuth of maximum principal stress at the same airfoil and the same measuring point,which result in significant differences in the maximum principal stress azimuth.
small wind turbinewind direction changeblade materialstress analysis
万方数据
维普
