Improved Buckling Resistance in Wind Turbine Blades Through the Production of GFRP Composites with Enhanced Resins

Abstract

The shear and transverse stiffnesses of unidirectional glass fiber reinforced polymer (GFRP) composites, which constitute a significant portion of wind turbine blades, are dominated by the resin properties. Accurate analysis and therefore optimized usage of such materials are critical in design of super-sized offshore blades, whose macro-structural properties may be improved through use of enhanced resins. In this paper, the properties of GFRP composites made using resins with assumed enhanced properties are accurately predicted using the Continuous Periodic Fiber Model (CPFM) and inserted into macroscopic finite element blade models of 33 and 100 meter lengths. Changes to blade performance in terms of buckling, bending, torsion, and trailing edge shear are quantified. Resins of increasing Young's modulus demonstrated increased blade transverse stiffness and postponed the buckling failure onset. Delayed buckling provides the opportunity to decrease the overall blade mass, reduce the required core foam, and optimize cost/performance for large offshore turbines.