Specialists from the Moscow Aviation Institute (MAI) have developed an innovative method to increase the durability of polymer composites used in aircraft construction. By adding carbon nanotubes in an amount of only 0.05% of the total mass of the material, it was possible to increase the resistance of composite parts to cyclic loads by a factor of three.
Research conducted at MAI has shown that with a certain method of adding this component, the fatigue strength of samples increases by 45%, and their resistance to repeated loads increases threefold.
Nanotubes, which are hollow cylinders up to several tens of micrometers long, exhibit exceptional stiffness and strength — they are a thousand times stiffer than epoxy resin and a hundred times stronger than carbon fiber.
In the production process, nanotubes are evenly distributed in an epoxy binder reinforced with carbon fibers. To overcome the tendency of nanotubes to agglomerate, a two-stage mixing method was introduced, ensuring homogeneous distribution of particles. This allows effective use of their ability to block crack propagation: when a microcrack occurs, it either bypasses the nanotube, lengthening its path, or stops completely, without overcoming the obstacle.
Currently, researchers are studying the possibility of using the technology for the repair of aircraft structures — in particular, for strengthening adhesive joints of repair patches. The work is being carried out jointly with one of the industry's design bureaus.
