PSI - Issue 80

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Thi Ngoc Diep Tran et al. / Procedia Structural Integrity 80 (2026) 378–391 Thi Ngoc Diep Tran/ Structural Integrity Procedia 00 (2019) 000–000

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Fig. 14 Distribution of von Mises Stress before crack initiation and inclination angle of a) Primitive; b) Gyroid; c) Neovius; d) IWP. Despite differences in the materials used, the damage regions identified in this study - based on cross-sectional area and inclination angle distribution, show similarities to those reported in earlier experimental studies by Abueidda et al. (2019), Abueidda et al. (2017), Yu et al. (2019). Fig. 15a and Fig. 15b show the crack direction in Ti-6Al-4V fabricated uniform Primitve (volume fraction 67.18%) and Gyroid (volume fraction 66.08%) using SLM technique. In Primitive structure (see Fig. 15a), cracks typically propagate along interconnected hollow layers characterized by steep surface inclinations where stress is concentrated. Micro-cracks develop either perpendicular or parallel to the loading axis, similar to the observation in individual unit cell in Fig. 13a. In Gyroid (see Fig. 15b), cracks tend to form within the shear bands and often appear as isolated segments, resembling the crack pattern shown in Fig. 13b and aligning with regions of steep inclination angles, consistent with the observations made in this study.

Fig. 15 Cracks directions in Ti-6Al-4V fabricated a) Primitive (67.18%) b) Gyroid (66.08%) (Yu et al. (2019)).

5. Conclusions The compressive failure behavior of four typical TPMS-based ceramic unit cells (Primitive, Gyroid, Neovius, IWP) was investigated in this study. To focus on the influence of the cell geometry, four FE unit cell models were constructed with the same ceramic volume fraction. The findings established a rank order of compressive strength among the structures. IWP and Neovius demonstrated higher compression strength, followed by Gyroid and Primitive.