Research Highlights: Nicole Thomas
Nicole’s research of the mechanical behavior of fiber-reinforced composites is currently focused on the fracture mechanics of fiberglass-reinforced composites that utilize a reactive thermoplastic matrix. These composites have the potential to enable end-of-life recycling of wind turbine blades. Traditional wind turbine blades are made with an epoxy matrix that is not easily recyclable. As wind turbine blades continue to grow in size to increase the power output of a single turbine, it becomes increasingly important to facilitate the recycling of tons of plastic that would otherwise be abandoned in place or discarded in a landfill. The particular matrix material being studied exhibits characteristics of both thermoset and thermoplastic materials; during fabrication, a two-part resin is combined into a low-viscosity liquid that easily infuses between fiber reinforcements and cures into a thermoplastic composite that can be reformed into new shapes with subsequent introduction of elevated heat and pressure.
Defects introduced in the recyclable wind blade fabrication process are of great interest; the high-cycle fatigue nature of wind turbines makes the composite susceptible to crack propagation due to repetitive multiaxial loading. Composite interfaces at the adhesive joints that join parts of the blades together are also of interest, because the innovative chemistry that enables recyclability introduces new challenges that must be studied to ensure reliable composite/adhesive interfaces. Nicole’s research seeks to characterize the impacts of defects and interfacial properties in the aforementioned composite materials that are subject to fatigue loading to help NREL and IACMI develop long-lasting recyclable wind turbine blades.