Energy absorption of 3D printed multi-material elastic lattice structures

An evaluation of novel material mixtures and lattice structures in additive manufacturing was conducted by mixing flexible Agilus30, and stiff Vero materials. Body centered cubic lattice structures were manufactured in pure Agilus30, pure Vero, and mixtures of 35, 50, and 70 Shore A hardness levels. The lattice structures were impact tested using a drop tower recording acceleration, and compression tested using a load frame. Compression and tensile testing were also conducted on material samples. The results showed that the hypothesis that a material mixture produces superior energy absorption lattice properties was correct. The best mechanical properties in all tests was for the pure Vero material and lattice structures with the most absorption of energy, 5.76 J, however, it also resulted in the highest accelerations in the drop tower testing, 124 m/s². The 70 hardness mixture samples had the second-best mechanical properties, and the least acceleration, 8 m/s², suggesting better impact absorption properties, especially for applications such as helmets. Further material mixtures and multi-material printing of lattices structures can be used in the future to combine favorable mechanical properties of materials and tailor specific parts of a structure for specific functions.