Synthesis and static analysis of the deployable frame for a morphing wing

This article proposes a deployable frame for a morphing wing. The frame is redundantly constrained in structure, and therefore it has both merits of high structural stiffness and strength of a truss structure and motion flexibility of a mechanism. The primary element of the foldable frame is synthesized from the viewpoint of identical strength principle. The major structures of previous deployable wings are mostly based on prismatic joints. However, the deflections of the cantilevered links might not satisfy the primary geometry requirements of the prismatic joint. Therefore revolute joints are used in our deployable frame to avoid violating the geometry conditions for prismatic joints resulting from the different deflections of its contacting two parts. The deflection and slope of every joint node of the foldable frame is investigated within the deploying/folding process. Numerical analysis indicates that the deployment ratio of the foldable frame can be designed much larger than that of the existing morphing wing even considering the allowable deflection under the completely unfolded situations.