Origami-inspired Mechanical Metamaterials

Folding paper into a repeated, tessellated, origami pattern can increase the paper’s strength. Using these origami patterns as inspiration for the design of structural engineering materials can similarly enhance the materials’ properties. There are multiple aspects of origami-inspired material designs that can affect their strength and performance, such as the chosen origami fold pattern, the dimensions of the pattern, and the material from which the pattern is fabricated. Common patterns that have previously been shown to have advantageous properties include Miura, Ron Resch, Kresling, and Yoshimura origami patterns.In this thesis, three novel origami fold patterns were designed, parameterized, and mechanically tested. The three patterns included a triangular-based pattern, a rectangular-based pattern, and a square-based pattern. The first study parameterized the geometries of the novel triangular and rectangular based origami, and proved the patterns had higher specific strength moduli than a previously tested Ron Resch pattern made from the same material. The rigid polylactic acid samples fractured during impact testing, leading to the second study which used a rubber-like material to fabricate flexible triangular, rectangular, and square-based origami sheets. These sheets were capable of absorbing loads from multiple impacts without fracturing and were more effective than unpatterned sheets at absorbing impact loads. The third study focused on analysing a two-level, full-factorial, parameterization for the triangular origami patterns. The results of this analysis defined how the overall shape and curvature of the origami sheet varied as the fold angle was changed. The fourth study combined flexible and rigid materials to create multi-material origami sheets comparing the triangular, square, and Miura origami patterns. The results showed that the triangular pattern had the highest compression strength, with the Miura pattern being next strongest. The final study creates heat activated shape memory origami tubes that would be ideal for use as space-saving actuators. Overall, three new origami-inspired patterns were created in this thesis: a triangular-based pattern, a rectangular-based pattern, and a square-based pattern. They were shown to have high strength-to-weight ratios and were effective at absorbing impact loads. Consequently, the materials designed in this thesis would be ideal for lightweight structures and protective equipment.Ph.D