Polyurethane corrugated composites for morphing wing applications

The morphing wing can be considered as a wing with seamless control surfaces and high-lift devices, which is capable of changing its shape during flight. As a result, an aircraft with the morphing wing can fly multi-mission tasks effectively and efficiently. The morphing wing should be stiff in spanwise direction to withstand aerodynamic and actuation loads while, in chordwise direction, the wing should be compliant in order to allow shape change. In this thesis, corrugated carbon fibre reinforced polyurethane composite is introduced as a candidate for the skin of morphing wing applications as the corrugated composite is considered highly anisotropic. A parametric study of three corrugated profiles (sinusoidal, trapezoidal and U-shape) with differnet amplitudes and unit cell lengths was performed numerically using finite element analysis and compared with analytical model in order to investigate the effects of the corrugation geometry on the mechanical response under tensile load. The results indicate that the trapezoidal profile offers the lowest extensional stiffness followed by U-shape and sinusoidal, respectively. In terms of corrugation geometry, the extensional stiffness of the corrugation is inversely proportional to both unit cell length and amplitude. An aerodynamic analysis of an aerofoil with corrugated lower skin was performed experimentally at four different Reynolds numbers and compared with an aerofoil with smooth skin. The conclusion drawn from the wind tunnel testing is that the aerofoil with corrugated skin on the pressure side is feasible to be used for a morphing wing of a small unmanned aerial vehicle (UAV) that operates at Reynolds number of approximately 10[superscript 5]. A bench-top demonstrator was constructed as a proof of concept and experimentally tested for repeatability and structural integrity. Moreover, the mechanical advantage was evaluated through a simple experiment.Imperial Users Onl