PSI - Issue 79

Petru Mihai Margitas et al. / Procedia Structural Integrity 79 (2026) 348–353

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2.1. Materials and specimen manufacturing The specimens were manufactured using Digital Light Processing, with a commercial ANYCUBIC Photon – LCD printer having a LED UV, 405 nm, 25 W light source, a building volume of 115 x 65 x 155 mm, a XY resolution 2560×1440 pixels, 47 µm, with minimum layer thickness between 0.01 to 0.2 mm, a printing speed of 20 mm/h and using a 405nm UV Resin, commercially named Translucent Green. Previous studies on the influence of manufacturing parameters on tensile (Brighenti et al. (2023)) and fracture toughness (Brighenti et al. (2023)) for this technology and material helped to choose optimal manufacturing parameters, presented in Table 1. As a consequence, the specimens were manufactured in plane with 0.05 mm layer thickness, an exposure time of 3.6 seconds for each layer. The post processing procedure consisted in cleaning in Isopropyl Alcohol (IPA) for 5 minutes and curing for 5 minutes with UV radiation. Four specimens were manufactured for each lattice structure.

Table 1. Manufacturing parameters Specimen orientation

Layer thickness [mm]

Exposure time [s]

Cleaning [min] 5 (in IPA)

Curing [min] 5 (UV)

In plane

0.05

3.6

All the specimens were weighted in order to determine the mass (m*) and the lattice structures densities were determined ( ρ ∗ = m*/V*), with V * the volume of the lattice structure. The material density was determined by printing with the same manufacturing parameters some cubes of 10 mm edge, which were also weighted, to obtain the solid density ( ρ S = m S /V S ). Then, the relative densities of the lattice structures were determined as ρ ∗ /ρ S . 2.2. Compression tests Compression tests of lattice structures were performed in displacement control conditions on a Zwick ProLine Z005 testing machine, Fig. 2, characterized by a maximum load of 5 kN, at room temperature (23 ° C) with a loading speed of 5 mm/min. A digital camera was employed to record the test.

Fig. 2 Experimental set up