One of the key technologies of the FRP wind turbine is the development of composite blades, it relates to the field of aerodynamics, structural dynamics, structure test, composite materials, process manufacturing, mold equipment. The technical difficulty is relatively large. At present, most of the world’s blades are made of glass fiber reinforced plastic composite material. The main consideration is that there are some advantages of FRP / composite material which are not available in other materials.
(1) it’s design strength and stiffness can be decided according to wind turbine blades force characteristics, use of fiber stress based theory, the main fiber in the longitudinal direction of the blade, reduce material consumption and the blade weight.
(2) easy molding. Pultruded blade has complex aerodynamic shape, it’s not easy to manufacture by metal, but composite materials is much easier to manufacture, after the mold can be made for mass production.
(3) excellent mechanical properties. Blade service life is about 20 years, the blade has a good fatigue strength. The fatigue strength of glass fiber is high, the notch sensitivity is low, and has good fatigue performance. In addition, the internal damping of the FRP is large, and the seismic performance is better.
(4) good corrosion resistance. In recent years has vigorously develop offshore wind farm installation for wind turbine, wind turbine installation at sea, the wind turbine and blade to affected by all kinds of climate and environment, to have the performance of acid, alkali, water vapor. While the glass steel composite material has this kind of good performance, it can work in the harsh environment for a long time.
