PSI - Issue 68

Antti Järvenpää et al. / Procedia Structural Integrity 68 (2025) 619–625 Antti Järvenpääa et al. / Structural Integrity Procedia 00 (2025) 000–000

624

6

with a relative density of 0.1 and 0.2, almost isotropic tension–compression YS values were measured, but the YS anisotropy ratio increased to 1.2 as the relative density increased to 0.5. The trend in tension-compression anisotropy of Young’s modulus (E’s) was similar between the lattice types (Fig. 6b) and followed a systematic decreasing trend. Tension E was significantly higher for all the structures, and the anisotropy increased as the relative density increased, reaching its highest value of 0.15 at a relative density of 0.5.

Fig. 6. the ratio between the compressive and tensile (a) yield strength (YS); (b) Young’s modulus (E).

3.5. Tension – compression anisotropy (Method B) The comparison between different calculation methods A (Fig. 6) and B (Fig. 7) shows quite similar trends in anisotropy, especially for the calculated E values. The trend in the YS anisotropy ratio of gyroid structures is parabolic rather than ascending or downward (Fig. 7a). On average, the YS tension–compression ratio of the gyroid structure is 1.05. The YS ratio of the stochastic structure is slightly downward, but on average 1.21, similarly to Method B estimations (AVG 1.25, Fig. 6a).

Fig. 7. The ratio between the compressive and tensile (a) yield strength (YS); (b) Young’s modulus (E).

3.6. Comparison to other lattice types and literature examples (Method A) The studied structures showed promising strength–density -combinations. In comparison to literature examples, the strength properties were generally better in the current study. Fig. 8a shows the comparison of compressive YS’s of the gyroid, neovius, and diamond lattice types. It is seen that in the current study, the calculated YS’s were similar to literature example /2/ at relative densities of 0.1 and 0.2, but significantly stronger at higher densities. At relative densities of 0.4 and 0.5, the gyroid structure reached the YS’s of the diamond-type lattice. The calculated E values were clearly higher than the ones presented in the literature example, especially at relative densities between 0.2 and 0.4, but the values remained much lower than the reference ones of neovius and diamond lattice types.