Homogenisation bounds for micro-architected polymer materials with extreme mechanical properties*

The aim of this work is the optimal design, additive manufacturing, and testing of micro-architected polymer materials with desired effective mechanical properties. The design process is discussed in terms of homogenisation bounds for composite materials. These bounds define the limits of the space of printable micro-architected materials.The optimal shape design process, uses topology optimisation via a level set method to identify material distribution and track boundary changes within the context of the smoothed interface, allowing us to capture the topological changes that take place within the unit cell. The designed microstructures were printed using stereolithography and mechanically tested. The results are analysed in terms of the overall effective elastic moduli and compared with a series of classical homogenisation bounds for composite materials, e.g. Hashin-Shtrikman, Milton-Kohn, etc. This discussion permits to better define the set reachable elastic coefficients by printing materials with controlled micro-architecture.

Agnelli, F., Constantinescu, A., & Nika, G. (2018). arXiv preprint arXiv:1809.02467.
Nika, G. Constantinescu, A. (2018). arXiv: 1804.02388.