4 Origami Structures

4.1 Origami-based Light-weight Energy Absorber

A series of tubular energy absorbers were developed based on origami structures. Two properties were focused on high energy absorption and light weight. The first property was improved by introducing origami patterns on the surface of thin-walled tubes. Using kinematic analysis, a relationship between the geometric parameters of the origami pattern and mechanical properties of the tube was established. Based on this relationship, the optimal pattern geometry could be obtained according to specific requirements of energy absorption. The second property was realized by adding windows on the surface of the tube. The effects of window shape and size on the energy absorption behavious of the tube were determined numerically and experimentally, based on which a windowed tube with reduced weight and equivalent or even higher energy absorption was developed.

Origami-based energy absorption tubes

Energy absorption tubes with patterned windows

4.2 Foldcore in Sandwich Structures

We introduced origami structures in the design of the foldcore of sandwiched structures to achieve high specific strength, stiffness and lightweight. A series of origami foldcores were designed and their mechanical properties were characterized numerically and experimentally. These structures could be utilized to design the fuselage of aircraft and the body of automobiles.

Sandwich structure with foldcore

4.3 Mechanical Metamaterials

A systematic design theory for origami-inspired mechanical metamaterial was developed. This theory made a full use of the inherent folding behavior of origami patterns, and generated large-scale metamaterials through 3D tessellation. Based on this theory, a series of mechanical metamaterials with 3D negative Poison’s ratio and tunable stiffness were proposed.

Origami-based mechanical metamaterials with negative Poison’s ratio in three-dimensions and tunable stiffness