Development of strong, stiff and lightweight compression-resistant mechanical metamaterials by refilling tetrahedral wireframes

ABSTRACT

Porous materials with excellent load-bearing capacity are essential for aerospace, shipbuilding, and biomedical devices where lightweight structures are required. In this study, a design strategy of mechanical metamaterials with a shell-based structure is proposed. By re-filling curved surfaces in the tetrahedral wireframe, closed cavities inside the structure are eliminated and the manufacturability is improved. The modified tetrahedron is mirrored, cut with specific proportions (25%, 50%, and 75%), and arrayed to form different structures. The compression performance of the structure is investigated using stereolithographic specimens and numerical methods. Compared with the mechanical metamaterials based on triply periodic minimal surfaces (TPMS) and strut-based structures, the new shell-based structures exhibit excellent strength and stiffness. The compressive strength and Young’s modulus of the structure with 50% cutting proportion are increased by 65% and 80%, respectively, compared with the Gyroid structure. This study offers a new design strategy for mechanical metamaterials with excellent compression-resistant capability.

KEYWORDS:

• Mechanical metamaterials
• mechanical properties
• structural optimisation
• light-weighting
• additive manufacturing

Disclosure statement

No potential conflict of interest was reported by the author(s).

Data availability statement

All data that support the findings of this study are included in the article.

Additional information

Funding

This work was supported by the Shenzhen Fundamental Research Program [Grant number JCYJ20220818102403007], the National Natural Science Foundation of China [Grant number 52205305], the Guangdong Natural Science Foundation [Grant number 2023A1515012439], and the Shenzhen Natural Science Foundation (the Stable Support Plan Program) [Grant number GXWD20231129125422001].