Project: Morphing aircraft wings
School: University of Maryland
Location: College Park, Md.
Director: Norman M. Wereley
In an attempt to make aircraft safer, more efficient and versatile, the aerospace industry introduced morphing technology. Using advanced materials and technologies, morphing aircraft can change from one configuration to another. They can maneuver much like birds.
Birds use camber and twist for flight control. In essence they can alter their wings to switch between cruise and attack mode. The idea of morphing aircraft wings is to mimic this flexibility, thus allowing planes to reduce drag, improve range, reduce vibration, control flutter and expand the flight envelope.
Morphing technology has been implemented in military aircraft such as the F-14 Tomcat, F-111 Aardvark and B-1 Lancer. “The morphing aircraft fielded to date all employ discrete, single-point morphing mechanisms, such as wing sweep, that limit the changes in aircraft performance due to limited changes in vehicle shape,” says Norman M. Wereley, techno-sciences professor and associate chair of the Department of Aerospace Engineering at the University of Maryland. “This approach also creates weak points in the wing structure, which require significant reinforcement and thus incur a substantial weight penalty.”
The University’s Composites Research Laboratory (CORE) is currently developing composite materials capable of large shape changes for use in morphing aircraft wings. Instead of the usual rigid resin, these composites use a flexible elastomeric matrix that has been dubbed elastomeric matrix composite (EMC) skins. The fiber in the EMC is unidirectional, so the skins are very rigid when pulled in the fiber direction. However, they are compliant when pulled perpendicular to the fiber direction.