Development of fibre composite based flexible skin for aerospace structures

Morphing wing technologies are an important research field for improving aerodynamic efficiency and enabling adaptation to varying flight conditions in next-generation aircraft. The objective of this thesis is to develop carbon fiber-reinforced composite skin structures with sinusoidal surface geometries that can reduce the trade-off between flexibility and structural strength in morphing wing applications, and to experimentally investigate their mechanical behavior. In this study, the hypotheses that sinusoidal geometry can provide shape-changing capability while maintaining a certain level of load-bearing resistance, and that layer count has a decisive effect on this behavior, were tested. Within the experimental scope, a total of nine specimen groups were produced by combining three different sinusoidal wave geometries with three different layer counts. The specimens were manufactured using the vacuum infusion method and evaluated through tensile, flexural, fatigue, and spring constant tests. The findings showed that single-layer specimens exhibited high flexibility but had limited load-carrying capacity. As the number of layers increased, load-carrying capacity, flexural stiffness, spring constant, and cyclic mechanical stability increased significantly. However, high layer counts were found to limit deformation capability. As a result, experimental design data defining the flexibility–stiffness balance for morphing wing skins were obtained by jointly evaluating sinusoidal geometry and layer count.