Quasi-static mechanical properties of origami-inspired cellular metamaterials made by metallic 3D printing

Abstract

Cellular mechanical metamaterials based on origami folded structures have attracted much attention due to their high designability in the mechanical properties. While origami cellular metamaterials (OCMs) made of plastics via 3 D printing have been studied extensively, those fabricated by metallic 3 D printing are relatively rare. This article presents a systematical experimental and numerical study on the quasi-static mechanical properties of 3 D-printed metallic OCMs based on various origami configurations and revealed the relationship between their key design parameters and mechanical performance. First, the OCM specimens based on the Miura pattern were fabricated using a metallic 3 D printing method, and compression tests were carried out to obtain their mechanical responses. The experiment results showed that the OCM specimens made from stainless steel exhibited large elastoplastic deformation, whereas early fracture of the material occurred in the aluminum alloy and titanium alloy specimens, and those with smaller cell size and wall thickness showed enhanced mechanical performance. Second, the FE modeling method for the metallic OCMs was developed and validated with the experiment data. Parametric studies on the compressive behaviors of metallic OCM models based on the two-stage Miura, perforated Miura, graded Miura, and cube pipe structures were then conducted. The relationships between the key geometric parameters and mechanical performance of various OCM models were disclosed. This work can provide a practical guide for the design and fabrication of 3 D-printed metallic OCMs.