Aeroelastic Analysis of Composite Wind Turbines Blades

Aeroelasticity is the main source of instability in structures under the influence of aerodynamic forces. One of the most important type of instabilities is coupled bending-torsional vibration, which is called flutter. In this paper, the aeroelastic stability of a composite wind turbine blade has been studied. Geometry, layup, and loading of the composite turbine blade have been compared with other structures. To study the phenomenon of the blade flutter, two numerical and analytical methods have been used. Finite Element Method (FEM), and JAR23 standard have been used in the numerical studies. Three-dimensional dynamic analysis of the blade loading has been carried out; the flutter phenomenon has been investigated in turbine blade by using the FEM that includes torsion and bending modes. Two-dimensional classical method of analytical analysis has been used to estimate flutter speed. Results of the numerical method provide safety factors of 4 and 1.39 for stress analysis and aeroelastic stability, respectively. Also, the analytical method gives the safety factor of 1.38 for aeroelastic stability, which has good agreement with the results of numerical method.