Self-repairing cracks - composite materials of the next generation

Because engineers are afraid of getting cracks, they now build airplane parts that are stronger, and therefore heavier, far beyond what is necessary so that they can lose up to forty percent of their strength during use. Solving the problem without burdening you will also allow you to save fuel

An important advance for the preparation of materials capable of inhibiting the formation of cracks and even leading to their self-repair has occurred thanks to a new joint venture by researchers from the University of Bristol in the United Kingdom and King's College London.

The new research will focus on carbon fiber polymer-based composite materials consisting of a combination of strong and stiff fibers with polymers to make strong, stable and lightweight materials. These materials are extremely important in the automotive and space industries that use carbon fibers to manufacture airplane wings, helicopter rotor blades and ship hulls.

However, the use and development of composite materials is limited due to the fear that they are prone to defects and damage. Dr. Emile Greenhalgh from the Center for Composite Materials at King's College London explains that because of this, current applications use very heavy parts that lead to increased fuel consumption: "Because engineers are afraid of getting cracks, they now build aircraft parts that are stronger, and therefore heavier, a lot beyond what is necessary so they can lose up to forty percent of their strength during use. This means that a higher amount of fuel is needed to take off and fly planes to their destination, so the impact of aviation on the environment is more harmful," he says.

The goal of the new research is the development of "personally designed" composite materials that prevent the development of cracks and even lead to their self-repair and that can be used as reliable, lighter and safer building materials for the production of fuel-efficient airplanes, trains, cars and ships.

In order to achieve this goal, the team will inject materials that will divert the original crack path and absorb the fracture energy resulting from it. Once the cracks stop, the researchers will use materials that will "bleed and congeal" while repairing the cracks and restoring as much of the material's original strength as possible.

One of the researchers explains: "Nature serves as an extensive source of inspiration to improve the planning and design of more efficient buildings. In addition to strength and stiffness, properties such as stickiness and self-repair are very common among a variety of biological materials, many of them composites. This project intends to explain and implement a variety of innovative approaches to promote a breakthrough in the performance of advanced composite materials."