Session: 16-01-01: Poster Session: NSF-Funded Research (Grad & Undergrad)

Paper Number: 99328

99328 - Buckling-Induced Functionalities of Origami Tubes 

Thin-walled origami-inspired tubes can be used as lightweight systems for various functional applications in engineering. Folding motions allow for deployment, reconfiguration, and compact storage of the systems, while buckling of the thin walls can be used to tune the system properties or achieve secondary functions such as energy absorption. Here we aim to explore how the local buckling affects the multi-stability and creates functions which are otherwise not achievable.

First, we explore a deployable design where origami tubes extend, lock, and absorb energy through crushing (buckling and plasticity). Numerical and experimental studies are used to investigate the tunable stiffness and energy absorption behaviors of these systems under static and dynamic scenarios. The stiffness, peak crushing force, and total energy absorption of these origami tubes can be changed through reconfiguration. When the origami tubes are only partially deployed, they exhibit a nearly elastic collapse behavior; however, when they are locked in a more deployed configuration, they can experience non- recoverable crushing with higher energy absorption. These deployable systems can increase the crushing distance between impacting bodies and can allow for on-demand energy absorption characteristics.

The rigid-foldable origami tube is equipped with additional mechanisms to maintain the deployed state, whereas a multi-stable tube can naturally stay at multiple configurations. A famous example is the bendy straw that can morph and lock in both axial and bending deformations, and here we explore how the multi-stability can be affected by the geometry. Finite element models and a reduced-order elastic simulation package can capture the nonlinear multi-stable behaviors. A simple linkage mechanism and physical models demonstrate the effects of longitudinal and cross-sectional geometries, respectively. We find the bending stability of a circular two-unit corrugated tube is dependent on the longitudinal geometry and the stiffness of the crease lines that connect separate frusta. Thinner shells, steeper cones, and weaker creases are required to achieve bending bi-stability. We introduce modified cross-sections for the corrugated tubes and explore how the new geometries affect bending stability, energy barriers, and stable configurations.

For the multi-stable corrugated tubes, we then propose a versatile origami design that shows drastically different multi-stability with different geometries. By tuning the geometry, the origami tube can behave either like a straw or like a Kresling origami tube that can switch among multiple stable states via a twisting motion. For the latter category, it can be reconfigured into a shape with high load-bearing capacity. Such a stable state can be achieved through the local snap-through buckling of valley creases. The origami tube then gains high stiffness in both axial and bending directions. Using a reduced-order simulation package based on elasticity, we investigate the underlying mechanics of the pop-up stability, quantify the tunable stiffness, and find the tuning of the deformation mode. The pop-up multi-stability and stiffness tuning are demonstrated by paper prototypes. Finally, we present conceptual applications based on this tube design, including a tunable energy absorber, deployable traffic cone, and reconfigurable robotic arm.

Presenting Author: Zhongyuan Wo The University of Michigan

Presenting Author Biography: A Ph.D. candidate from the Department of Civil & Environmental Engineering at the University of Michigan.

Authors:

Zhongyuan Wo The University of Michigan
Evgueni Filipov The University of Michigan