Failsafe layer for wind turbine blades: Erosion protection of glass fiber composite through nanodiamond-treated flax composite top layer.

Wind turbine blades are mainly made from E-glass fiber (GF) epoxy composites, because of their good ratio of strength to weight and costs. With the increase in blade length and tip speed, the problem of leading edge erosion is becoming more severe, reducing annual energy production and raising maintenance cost. It was recently shown that nanodiamond-treated flax fiber (FF ND) composites have significantly less erosion than GF composites and could be an alternative for GF in the turbine blade aeroshells. However, FF ND alone might not be suitable for manufacturing turbine blades at the large scale of modern wind turbines. Here, we show that a hybrid composite with a thin layer of only 1.5 mm of FF ND on a GF base, can achieve the same superior results as bulk material FF ND composite. In addition, we show and explain why aramid fibers, that are known for impact resistance, do not perform well as erosion protection. Our research shows the great potential of this technology to be implemented as a low-cost, lightweight skin layer on the leading edge. Acting as damage-tolerant failsafe layer, negligible ∼ 0.04 % extra weight of the FF ND could increase the blade's base erosion resistance by a factor of 60±20 compared to plain GF, expanding the repair window, reducing costs, and enhancing reliability. [Display omitted] • FF ND /GF hybrid composite has same superior erosion resistance as bulk FF ND composite • Acoustic energy measurements indicate material failure as main energy absorption channel. • High energy absorption and mass loss disqualify AFs for erosion protection. • Low-cost, lightweight FF ND skin layer can increase erosion resistance of turbine blades by a factor of 60±20. [ABSTRACT FROM AUTHOR]