Parametric Study of a Composite Skin for a Twist-Morphing Wing

Abstract

Although the benefits of morphing wings have been proven in many studies in the last few decades, the wing skin design remains one of the challenges to advancing and implementing the morphing technology. This is due to the conflicting design requirements of high out-of-plane stiffness to withstand aerodynamic loads and low in-plane stiffness to allow morphing with the available actuation forces. Advancements in the design of hybrid and flexible composites might allow for design solutions that feature this balance in stiffness required for this application. These composites offer new design parameters, such as the number of plies, the fiber-orientation angle of each ply in the skin laminate, and the spatial distribution of the plies on the skin surface. This paper presents a parametric study of a composite skin for a twist-morphing wing. The skin is made of periodic laminated composite sections, called “Twistkins”, integrated in an elastomeric outer skin. The twisting deformation is localized in the elastomeric sections between the Twistkins. The design parameters considered are the number of plies in the composite Twistkins, the fiber-orientation angle of the plies, the torsional rigidity of the elastomer, the width ratio, and the number of elastomeric sections. The computational analysis results showed that the torsional compliance can be increased by increasing the width ratio, decreasing the number of elastomeric sections, number of composite plies and the elastomer’s torsional rigidity. However, this would also lead to a decrease in the out-of-plane stiffness. The nonlinearity and rates at which these parameters affect the skin’s behavior are highlighted, including the effect of the fiber-orientation angle of the laminate plies. Hence, the study guides the design process of this twist-morphing skin.

Deformation control method for active shape morphing lattice structure using topology optimization approach

“…Figure 5 illustrates the relationship between the thermoelastic force and the current ratio. When θ ∈ [0, 1], the relationship changes as described in equation (2)(3)(4)(5)(6)(7)(8)(9)(10)(11)(12)(13)(14)(15). When θ ∈ [1, +∞), the thermo-elastic force reaches its maximum and remains constant.…”

“…have the potential to minimize design compromises inherent in traditional approaches [8,9], while morphing skins can ensure substantial deformations, low in-plane stiffness, and high outof-plane stiffness [10,11]. The integration of morphing capabilities allows for the development of novel structures and tools.…”

A Multiaxial Fracture of Ecoflex Skin with Different Shore Hardness for Morphing Wing Application

“…Additionally, the impact of environmental conditions such as temperature, humidity, and UV exposure on the mechanical properties of Ecoflex could be explored to assess its suitability for long-term use in various morphing wing structures. On the basis of current work following the work of King et al [ 35 , 36 ] and Bishay et al [ 37 ], soft metamaterials with tunable stiffness and poisson’s ratio can be developed adding fibers and controlling their orientation. The new elastomeric composite materials with higher stretngth, improved stretchability and fracture toughness and improved performance can be compared with that of Ecoflex under different loading conditions.…”

A Polymorphing Wing Capable of Span Extension and Variable Pitch

“…Finally, high-fidelity aerodynamic analysis using the ONERA elsA code [27] showed that the wing retrofitted with this device improved the airplane aerodynamic efficiency during high-speed climb conditions. In addition, Bishay and Aguilar [28] conducted a parametric study of a composite skin for a twist morphing wing. The skin consisted of periodic laminated composite sections called "Twistkins", integrated with an elastomeric outer skin, which facilitated localized twisting deformation between the Twistkins.…”