Searching for a Lightning-Proof Airplane Material

CFCs are increasingly used in airplane manufacture, as they are much lighter than Aluminium and are important weight savers. Dr Igor Golosnoy, of the University of Southampton's Electrical Power Engineering Research Group within the School of Electronics and Computer Science (ECS) is studying these carbon fiber composites and the damage that lightning causes them.

Dr Golosnoy is working with EADS on a three-year project analyzing the effects of lightning strikes on planes' shells and wind turbine blades, with the purpose of cutting back damage and repair costs. The researcher says that the increasing use of CFC has many disadvantages because of its specific structure. The composites are made of several layers of long carbon fibers saturated with epoxy resin and joined together. In each layer, the fibers are laid in different directions, which makes the composite highly electrically with different physical properties in different directions. Because of this positioning, the effects of lightning are different on each layer, which makes repair very difficult.

Dr Golosnoy specifies that: “we’re not talking about any immediate danger. Modern jets can still fly safely despite lightning strike damage. The problem here is that any damage should not remain undetected and must be repaired promptly. Our role is to establish in detail how the damage occurs in composite structures and to give suggestions on repair and protection as well as to look at possible improvements in CFCs themselves.”

“Although CFCs are strong and provide a superior mechanical performance, their electric and thermal conductivities are much lower than those of aluminium alloys. As a result the energy from the strike does not dissipate quickly enough along the unprotected surface, making them more susceptible to damage,” he adds to AlphaGalileo.

Finally he explains that “there are several ways to protect the composites, such as having a layer of metal mesh or thin foil on the top, but this increases the overall weight and means that both the coating and the composite get damaged. It also makes the repair procedure even more complicated.”

This project will mainly analyze the physics of the phenomenon and Dr Golosnoy begins to develop a qualitative mathematical model that could predict the behavior of the airframe during lightning strike.