Researchers at the Massachusetts Institute of Technology (MIT), United States, have devised a new way to detect internal damage to advanced composite materials, such as those being used by many airplane manufacturers. More and more airplanes are being constructed with these composites, which consist of high-strength fibers, such as carbon or glass, embedded in a plastic or metal matrix. These new materials are stronger and more lightweight than conventional materials, but are also more difficult to inspect for damage, because their surfaces do not reveal underlying problems. “With aluminum, if you hit it, there’s a dent there. With a composite, oftentimes if you hit it, there’s no surface damage, even though there may be internal damage,” says Brian L. Wardle, an associate professor of aeronautics and astronautics. The new detection approach uses a simple handheld device and a heat-sensitive camera, and requires the composite materials to include carbon nanotubes, which generate the heat necessary for the test. This approach could allow airlines to inspect their planes much more quickly. Other structures that use advanced composite materials, such as cars, bridges, and wind-turbine blades, could also use this technology. The article can be viewed online at the link below.
http://web.mit.edu/newsoffice/2011/seeing-below-the-surface-0324.html