Researchers have invented a new self-healing fiber-reinforced composite that allows structures of wind-turbine blades, aircraft wings, etc. to repair themselves without having to be removed from service
Previously used self-healing composites to repair structural components faced two major drawbacks. First, the materials often need to be removed from service to heal as some require heating in an oven. Second, these materials could self-heal only for a limited period for eg. after healing a few times their self-repairing properties would significantly diminish. Therefore to overcome these two issues, researchers from North Carolina State University have developed a unique self-healing composite that enables structures to repair themselves in place, without the need of removing them from service.
“By increasing the longevity of these composites, we make them more sustainable,” Patrick says. “And while wind-turbine blades are a good example, structural composites are found in a wide variety of applications: aircraft wings, satellites, automotive components, sporting goods, you name it.”
The process of how these self-healing fiber-reinforced composite works are as follows:
The layers of fibrous reinforcement e.g. glass and carbon fiber, are combined to fabricate laminated composites. Damage to structural components occurs when the “glue” that binds these layers together begins to peel away from the reinforcement or delaminate. The research team solved this issue by 3D printing a pattern of the thermoplastic healing agent onto the reinforcement material. The researchers also included thin “heater” layers in the composite. When an electrical current is applied, the heater layers warm up. This allows the melting of the healing agent, which flows into any cracks or microfractures within the composite and repairs them. The printed thermoplastic also improves inherent resistance to fracture by up to 500%, this shows that it requires more energy to cause delamination. Furthermore, the healing agent and heater layers are all made of readily available materials and are relatively inexpensive.
“We’ve demonstrated that this multi-functional technology works,” Patrick says. “We’re now looking for government and industry partners to help us tailor these polymer-based composites for use in specific applications.”
One more advantage of this new technology is, if incorporated into aircraft wings, the internal heating elements would allow airlines to stop using chemical agents to remove ice from wings when aircraft are on the ground, and also to de-ice in flight. Now, implementing this new research will enable users to rely on a given structural component, such as a wind-turbine blade, for a much longer period of time without worrying about failure
Click here for the Published Research Paper