Study Of Carbon Fiber Molding Process And Its Application In Megawatt Wind Turbine Blades

Carbon fiber have gained substantial interest over the last years, mainly due to its low density, high strength, high modulus, high temperature resistant, corrosion resistance, resistance to friction, conductive, thermal conductivity, small thermal expansion and other excellent characteristics. These properties lead to carbon fibers are generally used as reinforce of composite material, and improve the properties of composite. In order to reach higher turbine power, the length of the blade is increasingly getting longer. It is compulsory to use carbon fiber in wind blade.This paper studies the physical properties of E-5300, E-3325epoxy resin matrix materials and the mechanical properties of unidirectional carbon fiber reinforced polymer composites. Epoxy resins are used as matrix. The unidirectional carbon fiber is molded to carbon fiber reinforced polymer composites (CFRP) by vacuum infusion molding. By using digital viscometer, differential scanning calorimetry (DSC) test the viscosity and glass transition temperature of epoxy resin system. Using the material testing machine test the tensile, compression, in-plan shear performance of carbon fiber composites, and investigat the mechanical and interfacial properties of both0and90degree carbon fiber composites. Fracture surfaces are observed by scanning electron microscope.The results show that within the scope of this experiment, two kinds of epoxy resin matrix have low viscosity, a long working life and good toughness, and their glass transition temperature are86.38℃(E-5300) and89.30℃(E-3325). Via comparing the epoxy resin viscosity-time curve, one can be concluded that there is a low viscosity platform of E-5300epoxy resin, but E-3325epoxy resin does not exist low viscosity platform. By the mechanical properties testing obtained that the carbon fiber/epoxy resin (E-5300) composite material had good mechanics performance and high temperature resistance, such as the0°,90°modulus of elasticity are117.58GPa and7.05GPa, the0°and90°compression strength are803.1MPa and153.7MPa, the shear strength and shear modulus are60.32MPa and3.81GPa, Tg exceed114.26℃. The carbon fiber/epoxy resin (E-3325) composite material have excellent mechanics performance, such as the0°and90°modulus of elasticity are122.26GPa and7.73GPa, the0°and90°compression strength are851.8MPa and163.1MPa, the shear strength and shear modulus are60.61MPa and4.02GPa, Tg exceed115.37℃.By the mechanical properties test results and microscope analysis show the differences among the two carbon fiber/epoxy resin composites and epoxy resin, which helps to make the right choice for the wind blade manufacture.