Design and Fabrication of a Passive 1-D Morphing Aircraft Skin

Broad-scale area change of a non-porous surface while maintaining resistance to aerodynamic loading was demonstrated through the development of a passive elastomeric composite morphing skin. The combined system includes an elastomer-fiber-composite surface layer that is supported by a flexible honeycomb structure, each of which exhibit a near-zero major axis Poisson's ratio. A number of elastomers, composite arrangements, and substructure configurations were evaluated and systematic characterization testing led to the selection of the most appropriate components for prototype development. The complete prototype morphing skin demonstrated 100% uniaxial extension accompanied by a 100% increase in surface area. Results from out-of-plane pressure loading showed that out-of- plane deflection of less than 0.1-in can be maintained at various levels of area change under pressures of up to 200 psf. Applications to wing span morphing UAVs are also discussed.