Self-locking degree-4 vertex origami structures

Self-locking degree-4 vertex origami structures

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 induce self-locking so 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.

一般的4度顶点（4 - 顶点）折纸在刚性折叠时具有一个连续的自由度，并且当它的两个面结合在一起时，这个折叠过程可以停止。这种面的结合会引发自锁，使得整体结构保持在预先指定的构型，而无需额外的锁定元件或驱动器。自锁提供了许多有前景的特性，例如可编程的变形范围和分段刚度突变，这可能会极大地推动许多自适应结构系统的发展。然而，尽管其潜力巨大，但折纸的自锁特性尚未得到充分的研究、理解和应用。为了推进这一领域的技术水平，本研究对在4 - 顶点折纸结构中实现和利用自锁的原理进行了全面的研究。特别是，本研究首次将4 - 顶点结构的构建从单组件设计扩展到双组件设计，并研究了它们的自锁行为。通过利用各种镶嵌设计，本研究发现双组件设计为折纸结构提供了单组件结构所不具备的非凡属性，包括存在平折锁定平面、可编程锁定点和可变形性。最后，概念验证实验研究了自锁如何有效地引发分段刚度突变。本研究的结果为自锁折纸结构在许多潜在工程应用中的设计、分析和利用提供了新的科学知识和系统框架。