A solid-state piezocomposite variable-camber morphing wing is proposed for fixed-wing aircraft that operate in the low Reynolds number regime. An experimental evaluation of the wing which employs a continuous inextensible surface, continuous boundary conditions, and surface-bonded piezoelectric actuators is presented. The partially active surface is designed to have sufficient bending stiffness in the chordwise and spanwise directions to sustain shape under aerodynamic loading. In contrast, the in-plane stiffness is relatively high; however, the necessary deformations that are required to change the aerodynamic response can still be attained while maintaining the surface area constant. Coupled with the continuous boundary conditions and the spar structure, the prototype piezocomposite wing can achieve desired change in aerodynamic response quantified in terms of lift coefficient and lift-to-drag ratio. The experimental variable-camber, shell-like, morphing wing sustains aerodynamic loading at the maximum ...

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Piezoceramic composite actuators for a solid-state variable-camber wing

Integrated design of laminated composite structures with piezocomposite actuators for active shape control

Feedback tracking control for dynamic morphing of piezocomposite actuated flexible wings

Aerodynamic properties and aeroelastic responses of morphing wings can be improved via active shape control using piezoelectric actuators In this article, a type of piezocomposite material called 

Dynamic shape control of piezocomposite-actuated morphing wings with vibration suppression:

The work summarized here explores the application of various substrate materials to macro-fiber composites for the purpose of generating curvature. This research experimentally determines the free strain of the macro-fiber composite through its full range of actuation and then examines the resulting deflections when bonded to various substrates. In addition, loads are applied to the resulting unimorph while in a cantilever configuration and the deflections recorded. These results are used to validate finite element models, which are used to explore further design possibilities, including a bimorph configuration. The goal of this work is to determine the substrates that maximize curvature in both unloaded and loaded configurations. The results show that using thin and high modulus substrates results in the largest deflection under loading.

Investigating potential substrates to maximize out-of-plane deflection of piezoelectric macro-fiber composite actuators

‡‡ A novel morphing control surface design employing piezoelectric Macro Fiber Composite (MFC) actuators is compared to a servo-actuated system. The comprehensive comparison including aerodynamics, size, weight, power, bandwidth, and reliability has been extended to include flight test comparisons. Flight agility and control response of the morphing-actuated and servo-actuated configurations were quantified through state measurement during identical automated maneuvers. The morphing actuation scheme demonstrated superior response times and a fully controllable vehicle, but was unable to match the magnitude of roll and pitch rates attained by the servo-actuated baseline aircraft. The servo-actuated aircraft exhibited velocity deficits during doublet maneuvers, while the morphing actuation negligibly decreased velocity, demonstrating lower drag and more efficient production of control forces and moments. Reliability cycle testing of an MFC bimorph achieved 1 million cycles without failure and minimal degradation in performance.

Osgar John

Papers

Piezoelectric Morphing versus Servo-Actuated MAV Control Surfaces, Part II: Flight Testing