Miniscule cracks and flaws in the airframe of commercial and private aircraft can lead to catastrophic failure of the aircraft leading to loss of life and property. Commercial airlines routinely inspect their aircraft for damage and issues that could lead to an accident. The problem is that small cracks and light damage can be difficult to detect and impossible to see with the naked eye.
Aerospace engineers from Bristol University have developed a new method to complement routine visual inspections of commercial aircraft made from composite materials such as the Boeing 787 Dreamliner.
The researchers have devised a way to fill the hollow parts of composite aircraft with a self hardening resin. When the airframe is damaged the resin would bleed out of the hollow spaces into the crack and seal the damaged area with enough strength to maintain flight and safely land. The engineers also say that future aircraft could have the resin moving continuously through a circulatory system built-in to the airframe.
The resin doesn’t return the airframe to 100% of its strength, but the researchers say that the resin would allow the damaged area to regain 80% to 90% of its former strength. The process used by the engineers is likened to the process the human body uses to heal after a cut. In the body, blood leaks into the damage tissue where platelets form clots to stop bleeding and a scab forms to aid in healing and protect the area. In the engineers system the resin is the blood and the hardened resin is like a clot and scab protecting the area.
The resin the engineers propose to use would have a blue color allowing ground crews to readily identify areas where the resin has affected repairs to small areas of damage. Project leader Dr. Ian Bond said, “This approach can deal with small-scale damage that’s not obvious to the naked eye but which might lead to serious failures in structural integrity if it escapes attention. It’s intended to complement rather than replace conventional inspection and maintenance routines, which can readily pick up larger-scale damage, caused by a bird strike, for example.”