Energy absorption of graded thin-walled origami tubes

Introducing origami with outstanding flexibility into thin-walled tubes can enhance their energy absorption performance. This paper first proposes a cutting and folding-based design route of thin-walled origami tubes which enables geometry gradients such as uniform, tapered, hourglass-shaped, and ellipsoidal shapes. Subsequently, the finite element model of the proposed tube is established and verified through comparisons with experimental results. Numerical simulation results demonstrate that the quasi-static energy absorption capability of the graded thin-walled origami tubes is closely related to the folding angle, the total number of layers, and shapes. Compared with the conventional octagonal tubes (COT), the initial peak force in the proposed origami tube experiences a dramatic reduction, reaching a maximum decrement of 70.75%, while achieving a 39.96% boost in specific energy absorption (SEA). Moreover, the incorporation of gradient shapes within the origami tubes facilitates a more predictable and controlled collapse pattern, leading to an enhanced energy-absorbing efficiency than conventional uniform origami tubes. This study provides new insights into the design of thin-walled tubes that balance energy absorption and shape.