Numerical Analysis of Fatigue Life of Wind Turbine Blades Reinforced with Graphene Platelets

The rapid growth of wind energy has necessitated the development of advanced materials to address the increasing structural demands of wind turbine blades. Graphene platelets (GPLs) have garnered attention as a promising reinforcement material due to their outstanding mechanical properties, such as high strength and low density. This study investigates the fatigue life of wind turbine blades reinforced with GPLs, benchmarking their performance against conventional fiberglass blades. A finite element model of a 5 MW wind turbine blade was developed to evaluate stresses within the blade structure. The traditional fiberglass blade was modeled based on the SNL 61.5 m design by Sandia National Laboratories, while the GPL-reinforced composite (GPLRC) blade was designed by substituting fiberglass with GPLRCs. Material properties of the GPLRCs were determined using the rule of mixtures and the Halpin–Tsai micromechanics model. Wind speed data were randomly sampled following the probability distribution observed at European wind farms, and corresponding aerodynamic loads were computed using blade element momentum theory. Finite element analyses were performed to derive stress time histories, and fatigue life was predicted using the S-N curve approach, incorporating the Goodman diagram and the Palmgren–Miner rule. The results reveal that while GPLRC-reinforced blades exhibit some limitations in fatigue performance compared to traditional fiberglass blades, potential solutions for improving their durability are proposed, highlighting avenues for further research and optimization in the application of GPLRCs to wind turbine blades.