Assessing the Design and Compressive Performance of Material Extruded Lattice Structures

With additive manufacturing increasingly being embraced in the area of sports technology, focus has shifted toward cellular structures for impact protection. Periodic lattice structures can be tailored for a specific response by modifying the geometry of individual cells, with the structure capable of being modified to conform around a given body. However, the effect of modifying specific design characteristics within a lattice and the interrelationships between them are not well understood. This study examines five geometric design variables: cell width, strut cross-sectional area (CSA), strut shape, cell orientation, and joint filleting, and their effect on the compressive behavior of a lattice structure. Truncated octahedron lattices were manufactured using nylon through the process of material extrusion and tested under compression at a constant strain rate of 1.0 s -1 . Design of experiments was utilized to analyze the results by implementing a 2 (5-1) factorial design. Results indicated that the strut CSA, cell width, and interaction between the two design characteristics had the largest effects on the plateau stress of the lattice and its energy capacity.