PSI - Issue 68

Available online at www.sciencedirect.com Structural Integrity Procedia 00 (2025) 000–000 Available online at www.sciencedirect.com ScienceDirect

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Procedia Structural Integrity 68 (2025) 619–625

European Conference on Fracture 2024 Anisotropy of gyroid and stochastic lattice structures under axial loading Antti Järvenpää a *, Miguel Araya Calvo b , Timo Rautio a a Future Manufacturing Technologies Research Group, University of Oulu, Oulu, 90014, Finland b Bio-inspired Processes and Materials Research Group, Instituto Tecnológico de Costa Rica, Cartago, 30101, Costa Rica Abstract Lattice structures are an interesting possibility to tailor the strength-weight ratio and elasticity of metallic structures. In this study, Ti6Al4V gyroid and stochastic lattice structures with relative densities from 0.1 to 0.5 were manufactured by laser powder bed fusion technology, and the created structures were tested both under monotonic tension and compression to determine the strength properties and Young’s modulus. The study showed clear differences in anisotropy between the gyroid and stochastic lattice structures. In general, the anisotropy in the yield strength (YS) was higher in stochastic lattices, but the ratio between compression and tensile YS remained at 1.25 for all the studied densities. Higher variation was seen with gyroid lattices showing a ratio from 1.00–1.23 depending on the density. Gyroid structures were also stronger in strength, and superior strength levels were observed in comparison to the values found in the literature. The anisotropy in Young’s modulus (E) was high and significant differences were observed with different densities, but the trend between the gyroid and stochastic structures was similar. Interestingly, the ratio between compression and tensile Young’s modulus decreased by increasing the density, being close to 0.5 at 0.44 g/cm3 and 0.15 at 2.2 g/cm3. The measured E values were low, making them an especially promising solution for medical bone replacements. © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers Keywords: Additive manufacturing, lattice structures, gyroid, stochastic, implant materials © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers

* Corresponding author. Tel.: +358445551633. E-mail address: antti.jarvenpaa@oulu.fi

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers

2452-3216 © 2025 The Authors. Published by ELSEVIER B.V. This is an open access article under the CC BY-NC-ND license (https://creativecommons.org/licenses/by-nc-nd/4.0) Peer-review under responsibility of ECF24 organizers 10.1016/j.prostr.2025.06.106