Assessment of analytical relationships for mechanical properties of truncated octahedron and diamond lattice structures

• Published in: Materials today communications 2021-12, Vol.29, p.102756, Article 102756
• Main Authors: Guerra Silva, Rafael, Salinas Estay, Cristóbal, Morales Pavez, Gustavo, Torres, María J., Zahr Viñuela, Jorge
• Format: Article
• Language: English
• Subjects: Cellular materials; Cubic diamond; Lattice structures; Material extrusion additive manufacturing; Truncated octahedron
• ISSN: 2352-4928; 2352-4928
• DOI: 10.1016/j.mtcomm.2021.102756

Although several analytical models for the prediction of mechanical properties for truncated octahedron and cubic diamond lattices are available in the literature, no validation has been previously reported for most of them. In the present study, different analytical models were compared to results from compression tests of lattice structures built by material extrusion additive manufacturing, to determine their validity. For truncated octahedron lattices the relative error in geometry-based analytical models was significant, while models based on relative density showed better accuracy. In cubic diamond lattices, the relative error of the models was substantial, although performance improved for relative density values under 0.1. Discrepancies between the assumptions in the analytical models and the fabricated samples, in addition to size and edge effects were identified as possible sources of the large error margins observed. A second approach based on scaling laws was explored, and models for plateau stress and elastic modulus were obtained for both lattice structures, confirming its capabilities as an effective tool for the prediction of mechanical properties. Scaling laws and other models based on experimental data seem promising for the design of additive manufacturing lattice structures with a higher relative density, while further evaluation and development of the analytical models is considered necessary. [Display omitted] •Analytical models were compared to compression tests of lattices built by additive manufacturing to assess their validity.•The best predictions were observed for cubic diamond lattices with a relative density below 0.1.•Assumptions in analytical models, as well as size and edge effects in lattices were identified as possible sources of error.•Models based on scaling law could be a good fit for the design of AM lattice structures.•Further studies are required to test the validity of the available analytical models in structures with lower densities.