An approach of wrinkle suppression to corrugated-core flexible skin under bending

Flexible skin with an elastomer face sheet and corrugated core is considered the key component in achieving aerodynamic bearing and continuous large deformation of the morphing wings. However, during the bending deformation process, the compressed face of the corrugated-core rubber flexible skin is prone to wrinkling, which affects the aerodynamic shape of the wing. This study investigated the critical wrinkling load of a silicone face sheet under three-point bending. A flexible skin composed of a corrugated core and silicone face sheet was prepared for the three-point bending test. The transverse strain curve of the face sheet was obtained using the digital image correlation method. A finite-element model of flexible skin with a corrugated core was established. The wrinkling critical loads obtained by the simulation model and theoretical analysis are in good agreement with the experimental results. Furthermore, two improved silicone face sheets were obtained by increasing the partial thickness. The simulation and experiment results show that the improved face sheets can effectively suppress wrinkling. Meanwhile, the tenon structure formed by the trapezoidal silicone face sheet can enlarge the bonding area between the face sheet and corrugated core, and control the weight of the structure.