Mechanical instabilities in the origami hypar

This talk will highlight the mechanical characteristics of the origami hypar which is a bistable thin sheet structure with symmetric stable states. We use analytical and experimental studies to obtain the force-displacement characteristic of the structure, and to explore both the global and local behaviors. For the hypar to reconfigure between the stable states the thin sheet which is initially patterned with acute and reflex folds needs to fully flatten. However, depending on the geometry of the structure, local buckling can also emerge and can thereby allow portions of the origami to remain folded throughout the reconfiguration. A parametric study on different materials, sheet thickness, and fold line spacing is used to further evaluate and quantify the mechanical characteristics of the origami hypar.