Design Methodology for Optimized Lattice Structures for Structural Applications

This work presents a comprehensive bibliographic review of lattice structures by additive manufacturing, regarding their categorization, design parameters, their mechanical properties and applications within the current market. From such a review, a substantial lack of an easily applicable design methodology, for applying lattice structures to additively manufactured structural components, emerged. The goal was then set to study a design method where lattices, acting as a lightweight reinforcing structure, could be applied with the best performance to weight ratio. A simple test specimen where a lattice reinforcement could be applied was defined, and the lattice was set to live within a design space, where the geometrical properties of the lattice, the presence of skins and the geometric configuration of the reinforcing structure could change. The design of experiment was carried with the use of orthogonal arrays, following the practices described by Taguchi, to minimize the number of trials needed to study the impact of the design factors on specific performance. Two designs of experiment were set-up to test two sets of specimens, having different cells constituting the lattice, by finite element methodology. The resulting data was analysed and resulted in full accordance with the bibliographic material available, while giving good guidelines on how to seek optimum specific performance. The results were validated by designing the optimal specimens for each cell type. Finally, a design methodology, currently being applied to a real component, has been proposed.