Energy absorption of sustainable lattice structures under impact loading

Abstract: Lattice structures are increasingly used in various fields of application due to the steady growth of additive manufacturing technology. Depending on the type of lattice, these structures are more or less suitable for energy absorption due to the deformation of diagonal struts. The energy absorption properties depend significantly on the type of the selected lattice structure and its density, material properties, printing process, and post-treatment. Here, five lattice types (Octet, BFCC, Diamond, Truncated Octahedron and Rhombicuboctahedron) with different volume fractions are compared. Stereolithography is used to print the different lattices made from liquid resin. This allows good results to be achieved with tiny structures. In particular, the sustainability of energy-absorbing structures plays a significant role in many processes to withstand multiple loads. The lattice structures are made of TPU resin and offer different energy absorption properties without being destroyed under load. The structures are loaded abruptly using the Split-Hopkinson pressure bar test in a modified setup. From the measured strain pulses, we can calculate how much of the applied energy was absorbed by the different structures