An origami longitudinal-torsional wave converter

Wave mode conversion has received great attention in the past few years. In this work, we propose a Kresling origami wave-mode converter which can transform the longitudinal waves of one rod to hybrid or near-pure torsional waves in the other one. Both the converted transient and steady-state wave propagation as standing waves in the proposed rod system are studied with a special focus on the frequency-dependent wave-mode contributions. With a definition of a frequency-dependent conversion ratio of longitudinal wave to torsional wave (L-T Ratio), we investigate the generation of the combined or near-pure torsional waves. The longitudinal-torsional wave conversion frequencies are tightly associated with the initial geometrical parameters of the Kresling origami. An experimental system based on optical fiber Bragg gratings (FBGs) is set up to verify the Kresling-ori wave converter. The longitudinal-torsional wave converter based on the origami engineering has potential applications in wave manipulation, wave energy distributing, or unidirectional wave transmission. (C) 2021 Elsevier Ltd. All rights reserved.