Nonlinear Wave Dynamics of Origami-based Mechanical Metamaterials

We examine the potential use of origami structures, especially the Tachi-Miura Polyhedron (TMP) which is an origami bellows structure, as mechanical metamaterials. Focusing on the kinematics of its folding, we show that the TMP has unique characteristics, e.g., the Poisson's ratios change from positive to negative depending upon the crease pattern. In addition, we introduce a torsion spring to model the crease line of the TMP in order to study nonlinear wave dynamics. We derive analytical expression of the crease line's motions, where the folding behavior of the crease line provides nonlinear force-displacement responses both in compression and tension. These unusual characteristics lead to potential applications in impact absorption or energy transportation.