Fang, Qian-YiQian-YiFangTachi, TomohiroTomohiroTachiChen, Wei-QiuWei-QiuChenKUO-CHIH CHUANG2026-02-092026-02-092026-02-1500207403https://www.scopus.com/record/display.uri?eid=2-s2.0-105027448797&origin=resultslisthttps://scholars.lib.ntu.edu.tw/handle/123456789/735872In this paper, we design two types of degree-4 vertex self-locking compression-shear origami metamaterials that can manipulate, specifically convert, elastic waves. The origami metamaterials have shear deformation when being compressed and they will finally reach a self-locking state. We theoretically established the geometric and kinematic equations and experimentally verified the self-locking characteristics. Theoretical and mechanical testing results demonstrate that the geometry-induced coupling drives the shear deformation and leads to a stiffness jump upon self-locking. Furthermore, the bandgap characteristics and shear horizontal (SH) wave conversion capabilities of both types were investigated numerically and experimentally. Our results indicate that the near-self-locking state can induce a broad and complete band gap with a relative bandwidth of 87% due to non-uniform thickness and block bending waves below 100 Hz. Additionally, we show that input longitudinal waves will be converted to SH waves at specific frequencies, and our results demonstrate that a more rectangular geometry will lead to superior SH wave conversion performance. This work provides new insights and may serve as a reference for future engineering applications of origami-inspired structures.falseElastic wavesLow-frequency band gapsMechanical metamaterialsOrigamiSelf-locking stateShear horizontal mode conversionjournal article10.1016/j.ijmecsci.2026.1112422-s2.0-105027448797