Mechanical properties of corrugated composites for candidate materials of flexible wing structures

Corrugated-form composites are expected to be very flexible in the corrugation direction and stiff in the direction perpendicular to the corrugation. In this study, the corrugated composites manufactured from carbon fiber plain woven fabrics draw attention as a candidate material for flexible structural components, e.g. morphing wings. In-plane stiffness and strength of the original corrugated composites are evaluated through the tensile and bending tests in both in-plane longitudinal and transverse directions. A simple analytical model for the initial stiffness of the corrugated composites is developed, and the predictions are compared with the experimental results. Moreover, some improvements, installing of stiff rod and flexible rubber, are attempted for the creation of smooth aerodynamic surface and the improvement of stiffness. Mechanical properties of the modified corrugated composites are also evaluated and compared with those of the original corrugated composites. The applicability of the corrugated composites to the flexible wing structures are discussed based on the specific stiffness, longitudinal-to-transverse stiffness ratio, etc.