Tomita Sunao, Tachi Tomohiro
Toyota Central R&D Labs Inc. 1-4-14 Koraku, Bunkyo-ku, Bunkyo-ku,Tokyo 112-0004, Japan.
Department of General Systems Studies, Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-Ku, Meguro-Ku,Tokyo, Japan.
Philos Trans A Math Phys Eng Sci. 2024 Oct 7;382(2283):20240006. doi: 10.1098/rsta.2024.0006.
Origami folding structures are vital in shaping programmable mechanical material properties. Of particular note, tunable dynamical properties of elastic wave propagation in origami structures have been reported. Despite the promising features of origami metamaterials, the influence of the kinematics of tessellated origami structures on elastic wave propagation remain unexplored. This study proposes elastic metamaterials using connected Miura-ori tubes, the kinematics of which are coupled by folding and unfolding motions in a tubular axis; achieved by periodically connecting non-rotated and rotated Miura-ori tubes. The kinematics generate wave modes with localized deformations within the unit cell of the metamaterials, affecting the global elastic deformation of Miura-ori tubes via the coupling of wave modes. Dispersion analysis, using the generalized Bloch wave framework based on bar-and-hinge models, verifies the influence of kinematics in the connected tubes on elastic wave propagation. Furthermore, folding the connected tubes changes the coupling strength of wave modes between the kinematics and global elastic deformation of the tubes by breaking the ideal kinematics. The coupling of wave modescontributes to the formation of the band gaps and their tunability. These findings enable adaptive and tunability of band structures to prohibit elastic waves in the desired frequency ranges.This article is part of the theme issue 'Origami/Kirigami-inspired structures: from fundamentals to applications'.
折纸折叠结构对于塑造可编程机械材料特性至关重要。特别值得注意的是，已有报道称折纸结构中弹性波传播具有可调谐的动力学特性。尽管折纸超材料具有诸多有前景的特性，但镶嵌折纸结构的运动学对弹性波传播的影响仍未得到探索。本研究提出了一种使用相连三浦折管的弹性超材料，其运动学通过在管状轴向上的折叠和展开运动相耦合；这是通过周期性地连接未旋转和旋转的三浦折管来实现的。这种运动学在超材料的晶胞内产生具有局部变形的波模式，通过波模式的耦合影响三浦折管的整体弹性变形。基于杆-铰链模型的广义布洛赫波框架进行的色散分析，验证了相连管中运动学对弹性波传播的影响。此外，折叠相连的管子会破坏理想运动学，从而改变管子运动学与整体弹性变形之间波模式的耦合强度。波模式的耦合有助于带隙的形成及其可调谐性。这些发现使得能带结构能够实现自适应和可调谐，从而在所需频率范围内禁止弹性波传播。本文是主题为“受折纸/剪纸启发的结构：从基础到应用”的一部分。
