title: Self-locking degree-4 vertex origami structures.
abstract: A generic degree-4 vertex (4-vertex) origami possesses one continuous degree-of-freedom for rigid folding, and this folding process can be stopped when two of its facets bind together. Such facet-binding will induceself-lockingso that the overall structure stays at a pre-specified configuration without additional locking elements or actuators. Self-locking offers many promising properties, such as programmable deformation ranges and piecewise stiffness jumps, that could significantly advance many adaptive structural systems. However, despite its excellent potential, the origami self-locking features have not been well studied, understood, and used. To advance the state of the art, this research conducts a comprehensive investigation on the principles of achieving and harnessing self-locking in 4-vertex origami structures. Especially, for the first time, this study expands the 4-vertex structure construction from single-component to dual-component designs and investigates their self-locking behaviours. By exploiting various tessellation designs, this research discovers that the dual-component designs offer the origami structures with extraordinary attributes that the single-component structures do not have, which include the existence of flat-folded locking planes, programmable locking points and deformability. Finally, proof-of-concept experiments investigate how self-locking can effectively induce piecewise stiffness jumps. The results of this research provide new scientific knowledge and a systematic framework for the design, analysis and utilization of self-locking origami structures for many potential engineering applications.
authors.affiliation: Department of Mechanical Engineering , University of Michigan , Ann Arbor, MI 48109 , USA.
authors.forename: Hongbin
authors.identifier: 0000-0001-6691-0531
authors.initials: H
authors.lastname: Fang
authors.affiliation: Department of Mechanical Engineering , Clemson University , Clemson, SC 29634 , USA.
authors.forename: Suyi
authors.initials: S
authors.lastname: Li
authors.affiliation: Department of Mechanical Engineering , University of Michigan , Ann Arbor, MI 48109 , USA.
authors.forename: K W
authors.initials: KW
authors.lastname: Wang
keywords: facet-binding; mechanical metamaterial; piecewise stiffness; programmable structures