Additive manufacturing of overexpanded honeycomb core lattice structures and their characterization

Abstract In this paper, experimental and finite element (FE) analyses of the lattice structures resembling an overexpanded honeycomb core material were performed for different parameters for unit cells of the structures. The lattice structures produced using an additive manufacturing (AM) method. Polylactic acid (PLA) was used to manufacture the test specimens by Fused Deposition Modeling (FDM) method. Seven different test specimens were designed changing three parameters of unit cell with the same size of test specimens. All the test specimens were subjected to compressive load and parameter changes’ effect on mechanical properties, which are yield strength and Young’s modulus. For the validation of the tests, finite element analysis was performed. According to the results, experiments and the FE models gave similar outputs. First, decreasing the cell size, increasing the thickness of the cell edges, and increasing the unit cell angle enhance the strength and Young’s modulus of the lattice structures. Moreover, the structures with 0° and 90° angles of the unit cells show auxetic features, whereas the structures with 45° angles of the unit cells show nonauxetic features.