Topologically-tunable heterogeneous infills for 3D printing: a lattice design algorithm

This work presents a geometrical algorithm for generating heterogeneous lattice structures with continuous topology variation, tailored for Additive Manufacturing. The method focuses on beam-based cubic unit cells with octahedral symmetry, organized into three distinct classes that enable smooth transitions between topologies while preserving structural connectivity and printability. A finite element implementation of Asymptotic Homogenization is used to characterize the linear thermal and elastic effective properties of the generated lattices. The results are provided as data tables which, upon interpolation, define scaling functions that map bulk material properties to homogenized lattice properties, enabling reduced-order modeling of the lattice behavior. A novel taxonomy of unit cell topologies is proposed, and the performance of the algorithm is evaluated through comparative analysis of the scaling functions via class envelopes and topology plots. The tunability of the material behavior is referenced against the Hashin–Shtrikman bounds, highlighting the potential of the approach to cover a wide design space within the thermodynamical limits. This algorithm lays the foundation for a design methodology for the infill of 3D-printed components, with promising applications in optimization frameworks where both infill density and topology are spatially adapted.