Energy Absorption Studies on Lpbf Fabricated Hybrid-Dimensional Tpms Lattice Structure

Abstract

The paper introduces a new hybrid design method for a lightweight energy-absorbing structure's Triply Periodic Minimal Surfaces (TPMS) hybrid lattice structure. Traditional Diamond and Gyroid lattices are superimposed as a superlattice with different weights to obtain a hybrid lattice structure that combines the advantages of both. The ultra-high compressive ductility of the Al-Cu-Mg-Y alloy, achieved from our previous research, is utilized to form this lattice to delay early fracture as much as possible. The results indicate that the D6G4 (60% weight Diamond + 40% weight Gyroid) lattice type possesses the highest ultimate compressive strength σmax​​ and plateau stress σpl​​; thereby endowing it with the highest energy absorption and specific energy absorption. This is attributed to the D6G4 lattice having a relatively wider load-bearing area, and forming an interlaced grid structure in the direction of the maximum shear stress at 45°. This enables the effective dispersion of shear stress to other directions, thereby achieving optimal energy absorption characteristics.

Keywords: energy absorption, Al-Cu-Mg-Y alloy, hybrid TPMS lattice structure, Laser Powder Bed Fusion