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.

Effect of Epoxy Resin Concentration on Some Mechanical Properties of Carbon Fabric/ Nitrile Rubber Reinforced Composites

“…The enhancement in the E% property for all CFRP/NBR composites is due to the high elongation to failure of elastomers 12 . NBR has high strain capability and elastic recovery that enable it to undergo more elastic deformations under stress than fibers [20][21] . Thus, NBR grants the CFRP elastic and flexibility behavior that permit it to undergo more strain before failure than F1 composite.…”

Advanced Kinematic Tailoring for Morphing Aircraft Actuation

“…Originally invented in the 1950's by McKibben, 30 they have only recently been introduced into the field of aerospace engineering. 31,32,33 PAMs are made of an air-tight, inflatable bladder surrounded by an expandable sleeve braided from stiff filaments. The bladder and sleeve are initially cylindrical in shape, and the two ends are sealed with end fittings of various designs.…”

Morphing Trailing Edge Control Using Flexible Matrix Composite Actuators

“…The flap system is also tested under full scale aerodynamic loading in a wind tunnel. 16 Peel et al 17 developed inexpensive morphing wing concepts using pneumatic rubber muscle actuators. The actuators are located inside of an airfoil connecting the leading and trailing edges.…”