Topology optimization of self-supporting metamaterials for additive manufacturing: a novel framework and validation

Topology optimization (TO) for additive manufacturing (AM) often faces challenges related to overhang structures, increasing build time, material costs, and the need for support structures. This paper proposes a novel framework for designing and manufacturing two- and three-dimensional self-supporting metamaterials that eliminate the requirement for additional support during AM. By integrating an AM filter into the TO process, homogenization methods for evaluating elasticity properties, and a symmetry constraint to ensure connectivity between periodic unit cells, we demonstrate optimized self-supporting metamaterials. Manufacturability is verified through fused deposition modeling, and mechanical compression experiments confirm the performance of the resulting metamaterials. The approach offers a cost-effective and time-efficient solution for fabricating complex metamaterials without auxiliary supports.