Design and Application of Cross-Shaped Cellular Honeycombs for a Variable Camber Wing

Cellular honeycomb cores with overlying flexible skins have been proposed for use as deformable structures for morphing aircraft. Airfoils with a variable camber trailing edge require the camber to be changed continuously, which is pursued by the reconfiguration of both the underlying structures and the flexible skins. The honeycomb cores, which provide underlying support to the flexible skins for bearing the out-of-plane aerodynamic loads, must have low in-plane stiffness andhigh out-of-plane bearing capability. In this paper, a kind of cross-shaped honeycomb is designed and manufactured. Analytical, numerical, and experimental studies for the in-plane effective moduli of the cross-shaped honeycomb are carried out. The results demonstrate that the cross-shaped honeycomb has substantial in-plane deformability. A conceptual design of the variable camber trailing edge based on the crossshaped honeycomb is proposed and modeled using MSC.NASTRAN software. Simulation results show that the cross-shaped honeycomb can provide substantial in-plane deformation and adequate out-of-plane support, satisfying the deformability and bearing capacity requirements of the variable camber trailing edge.