Materiais compósitos aplicados na indústria eólica: análise comparativa de laminados de matriz de resina epóxi reforçados com fibras de carbono e fibras de vidro

Abstract

Investments in the wind energy sector have grown markedly in the last decade. Since the wind industry, more specifically the wind turbine and wind blade manufacturing industry, is one of the largest applications of composite materials, its development has entailed significant advances in the production of composites. In most cases, composite materials used in the wind industry have thermoset polymer matrices, such as epoxy resin, and are reinforced with fiberglass or carbon fibers. The use of glass fibers may be more favorable than the use of carbon fibers, which have a high cost. Therefore, the present work aimed to perform a test of raw materials, comparatively evaluating the properties of laminated composites applied in the wind industry manufactured with epoxy resin matrix and with glass and carbon fiber reinforcement. Through the hand lay-up process, two laminated composite plates of epoxy resin matrix were manufactured, one reinforced with bidirectional fiberglass and the other reinforced with bidirectional carbon fiber. Tensile tests were performed to analyze the mechanical properties of the plates and the glass transition temperature (Tg) was determined using the Differential Scanning Calorimetry (DSC) test. The glass-fiber-reinforced specimens had an average tensile strength limit of 141.30 MPa, while the average tensile strength limit of the carbon-fiber-reinforced specimens was 167.33 MPa. The yield stress and modulus of elasticity of the carbon-fiber-reinforced specimens were considerably higher than for the glass-fiber-reinforced specimens, with the difference being more than 39 MPa for the yield stress and more than 2540 MPa for the modulus of elasticity. The laminated composite reinforced with fiberglass and the one reinforced with carbon fiber showed very similar glass transition temperature and both were approved in the DSC test, having Tg higher than the established operating temperature. Finally, it was concluded that it is feasible to replace carbon fiber reinforcements with glass fiber reinforcements in certain applications of the wind industry’s components manufacturing, depending strictly on the required mechanic properties.