An Approximately Isotropic Origami Honeycomb Structure and Its Energy Absorption Behaviors

Abstract

Honeycomb structures have a wide range of applications owing to their light weight and promising energy absorption features. However, a conventional honeycomb structure is designed to absorb impact energy only in the out-of-plane direction and demonstrates unsatisfactory performance when the impact energy originates from a different direction. In this study, we proposed an origami honeycomb structure with the aim of providing an approximately isotropic energy absorption performance. The structure was created by folding a conventional honeycomb structure based on the Miura origami pattern, and it was investigated using both numerical and experimental approaches. Investigations of the structural behaviors under both out-of-plane and in-plane compressions were conducted, and the results revealed significantly different deformation modes in comparison with those of a conventional honeycomb structure. To determine the influences of geometries, we conducted a series of numerical studies, considering various structural parameters, and analyzed the response surface of the mean stress in three directions. Based on the numerical and experimental results, a parameter indicating the approximate isotropy of the origami honeycomb structure was introduced. The proposed structure is promising for absorbing energy from any direction and has potential applications in future metamaterial design work.

Keywords: approximately isotropic; honeycomb materials; origami metamaterial; response surface methodology.

Figure 1

Conventional honeycomb and origami honeycomb.

Figure 2

Geometric parameters of origami honeycomb structures: (a) overall structure, (b) coordinate diagram, and (c) geometric properties.

Figure 3

Hexagonal prismatic unit cells of origami honeycomb with different H.

Figure 4

Finite element model of origami honeycomb: (a) mesh on unit cell, and (b) schematic of finite element model.

Figure 5

Stress versus strain curves of different models (a) in the in-plane direction along the y-coordinate, (b) in the in-plane direction along the x-coordinate, and (c) in the out-of-plane direction.

Figure 6

In-plane crushing deformation of origami honeycomb along the y-coordinate.

Figure 7

In-plane crushing deformation of origami honeycomb along the x-coordinate: (a) symmetrical deformation pattern, (b) one-sided deformation pattern, and (c) compound deformation pattern.

Figure 8

Y-cellular in (a) symmetric deformation pattern; (b) one-sided deformation pattern; and (c) compound deformation pattern.

Figure 9

Distribution of deformation modes in the x-direction.

Figure 10

Out-of-plane crushing deformation of origami honeycomb.

Figure 11

Mean stress under the compression of the origami honeycomb: (a) in the in-plane direction along the y-coordinate, (b) in the in-plane direction along the x-coordinate, and (c) in the out-of-plane direction.

Figure 12

Origami honeycomb with $\theta =\mathsf{\pi }/3$

Figure 13

Out-of-plane crushing deformation of two Y-cellular cells when (a) $r=6.22\mathrm{mm}$ and $\theta =\mathsf{\pi }/3$, and (b) $r=6.22\mathrm{mm}$ and $\theta =\mathsf{\pi }/4$.

Figure 14

In-plane crushing deformation of Y-cellular cell along the y coordinate when (a) $r=6.22\mathrm{mm}$ and $\theta =\mathsf{\pi }/3$, and (b) $r=6.22\mathrm{mm}$ and $\theta =\mathsf{\pi }/4$.

Figure 15

Response surfaces of mean stress for origami honeycomb: (a) in the in-plane direction along the y-coordinate, (b) in the in-plane direction along the x-coordinate, and (c) in the out-of-plane direction.

Figure 16

Curved surface diagram of origami honeycomb cushioning capacity when (a) k ≤ 0.1, (b) k ≤ 0.15, (c) k ≤ 0.2, and (d) k ≤ 0.3.

Figure 17

Experimental equipment and specimen.

Figure 18

In-plane compression of origami honeycomb specimen along the y-coordinate.

Figure 19

Simulation stress–strain results and experimental measurements of Specimen 1 (a) in the in-plane direction along the y-coordinate, (b) in the in-plane direction along the x-coordinate, and (c) in the out-of-plane direction.

Figure 20

Simulation stress–strain results and experimental measurements of Specimen 2 (a) in the in-plane direction along the y-coordinate, (b) in the in-plane direction along the x-coordinate, and (c) in the out-of-plane direction.

Figure 21

Simulation stress–strain results and experimental measurements of Specimen 3 (a) in the in-plane direction along the y-coordinate, (b) in the in-plane direction along the x-coordinate, and (c) in the out-of-plane direction.