Development of a Simple Morphing Wing Using Elastomeric Composites as Skins and Actuators

Abstract

Morphing wings are desired for their ability to reduce drag, change flight characteristics, and perhaps reduce weight by eliminating flap / aileron mechanisms. Development of two generations of a student morphing wing project is documented. The second wing was further developed by Peel. The work shows how a relatively low cost but realistic morphing wing test-bed can be fabricated. Wing skin, actuator, and actuator attachment development are discussed, as well as possible auxetic skin behavior. Aerodynamic characterization of the wing will be discussed in another paper. A very simple morphing wing was fabricated in phase one. The nose was able to elastically camber down ∼ 25° and the tail 20°. Actuation was provided by three pneumatic “Rubber Muscle Actuators” (RMA) that produce high contractive forces. Upper and lower wing skins were fabricated from carbon fiber / polyurethane elastomer laminates. Lower skin buckling, actuator air leaks and actuator attachment problems were resolved in the second phase. A finite element model of the generation II wing was developed and is being used to refine/ explore the morphing wing test-bed. The second generation wing fabrication methodology shows smooth elastic cambering and no buckling or waviness in the skins. The nose cambered down 23° and the tail cambered down to 15°. Improved leak-free biomimetic actuators and attach points now include no metal parts, have higher actuation forces due to new braided sheaths and functionally gradient matrix properties.