Tuning Energy Absorption of Metallic TPMS Cellular Structures via Wall Thickness Gradient Design

Abstract

Background

In the study of laser melting fabricated 316L stainless steel triply periodic minimal surface (TPMS) structures, a knowledge gap persists. The understanding of optimizing deformation mechanisms and energy absorption, especially via gradient wall thickness design, remains inadequate.

Objective

The main aim of this research is to explore the deformation and energy absorption features of particular 316L stainless steel TPMS structures made by laser melting, emphasizing the use of gradient wall thickness design to improve overall energy absorption.

Methods

An integrated experimental and computational approach was developed. TPMS structures with diverse wall thicknesses were fabricated through laser melting. Then, detailed analyses were performed to examine stress and deformation under compression. The novelty was the local strategies in gradient wall thickness design for enhanced stress redistribution.

Results

Quantitatively, compared to uniform ones, the specific energy absorption (SEA) of gradient structures rose by 18.3% along the loading direction and 26.8% perpendicular to diagonal shearing. Qualitatively, the gradient design reduced early densification and improved stress redistribution, yielding new insights for future designs.

Conclusions

Overall, the strategic use of gradient design and wall thickness control significantly boosts the SEA of laser melting fabricated 316L stainless steel TPMS structures, showing great potential for future applications.