Deformation characteristics of corrugated composites for morphing wings

Abstract

To meet the needs of morphing and withstand aerodynamic loads of a morphing wing skin, a corrugated glass fabric-epoxy laminated composite is prepared and investigated in this paper. This composite is flexible in the corrugated direction and stiff in the transverse direction to the corrugation. FEM models are established and solved to predict the characteristics of the composites by the commercial FEM software ANSYS. The relationship between the configuration of elongation and tensile load along the corrugation direction is obtained through numerical simulation. To reflect the stretching superiority of the configuration, the elongation of corrugated and flat composites is calculated and compared under the same tensile load. The linear cumulative effect of corrugated composites deformation is proved by calculating the elongation of the composites with several different corrugation numbers. Several corrugated composite specimens were manufactured and tested to verify the results of numerical analysis and the equivalent elastic modulus of the composites were also evaluated through the specimen tests. Results of simulation and experiments show that the corrugated composite provided in this paper can afford obviously larger deformation than the flat one. The corrugated composite can provide a possible choice for morphing wing skin.

Review of morphing concepts and materials for wind turbine blade applications

“…Recently, Ge et al . modelled and tested a corrugated composite made of glass fibre fabric. A finite element model was created using ANSYS software, and correlation between computational results and experiment was found.…”

Corrugation Reinforced Composites: A Method for Filling Holes in Material‐Property Space

“…It is worth noting at this time that this study strictly focuses on a sinusoidal corrugated structure. This sinusoidal corrugated geometry is commonly used in the study of corrugated materials, [12][13][14]18,[21][22][23][24][25][26][27][28][29][30][31] however it is not the only corrugated geometry used and many other studies use trapezoidal corrugations, [15,19,20] and circular corrugations. [14][15][16] All of these corrugation geometries display similar increasing work hardening behavior when loaded in tension and the main difference between the geometries lies in the manner and location in which the unbending is focused, the amount of force required to unbend to a certain degree and the corresponding strain at which complete unbending has occurred.…”

“…Utilization of the corrugated geometry has been shown to have potential to increase the necking strain of a material as a result of the unbending of the corrugation during loading. As outlined in the review paper by Dayyani et al, [10] this improved elongation in the longitudinal direction coupled with high transverse stiffness has made the corrugated geometry an excellent candidate in the construction industry, the packaging industry in the form of corrugated board, as explored in Luo et al [11] and Gilchrist et al, [12] and more recently in the aerospace industry for use in morphing wings, as studied by Ge et al, [13] Xia et al, [14] Kress and Winkler, [15] Yokozeki et al, [16] and Park et al [17] Studies of isolated corrugations or corrugated sandwich structures by Thill et al, [18] Dayyani et al, [19] Bouaziz, [20] Boke, [21] and Fraser et al [22] found that when subjected to a tensile load the stress-strain response is characterized by initially low levels of stress followed by increasing work hardening behavior that can be attributed to the unbending corrugation, followed by normal plastic behavior of the material once the corrugation is straightened. Ultimately, this leads to the material necking at a larger value of strain compared to a straight sample.…”

Development of Variable Camber Morphing Airfoil Using Corrugated Structure

“…The loading, P, is applied to the wire to the leading edge direction, and deformation of the morphing section is simulated. Material properties of CFRP [21] are used for simulation, and the thickness of the corrugated structure and the upper thin skin is set to be 0.5mm (same as the real model described below). Numerical simulation demonstrates that the driving of the present morphing wing is possible.…”

“…stiff direction) coincide with chord direction and span direction of the wing, respectively. Several researches on morphing structures using corrugated structures follow recently [19][20][21][22]. It is expected that this structural concept is useful for realizing the variable camber airfoil or the conformal trailing edge control surface [23].…”