We investigate nonlinear wave dynamics in origami-based mechanical metamaterials composed of origami-based structures, specifically the Triangulated Cylindrical Origami (TCO). The TCO structure shows coupling behavior between longitudinal and rotational motions. One of the unique features of the TCO is that the unit cell can exhibit mono- or bistable behavior selectively, which is determined by initial configurations such as height and rotational angle. In this study, we first fabricate physical prototypes made of paper sheets, and conduct compression tests on the prototypes to verify this unique tunable mono-/bistable features. By utilizing this tunability, we design a 1D chain of the TCO unit cells in which mono-/bistable behaviors of each unit cell can be altered by geometric parameters. Then, we analyze wave propagation in this origami-based system numerically by applying impact to the end of the chain. When the monostable configuration is selected for all of the unit cells, our numerical analysis shows that the application of compressive impact creates a tensile solitary wave propagating ahead of the initial compressive wave. In addition, the wave speed of this tensile solitary wave can be manipulated by the configurations of the TCO unit cells. These unique tunable static/dynamic behaviors can be exploited to design engineering devices which can mitigate impact in an efficient manner.
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