Energy absorption in lattice-structured materials under impact loading
Sören Bieler, Kerstin Weinberg
Abstract
Due to their unique combination of lightweight and high strength, materials with a cellular microstructure are used to protect against impact or shock. In addition to foam-like materials, specially designed lattice-like structures have gained importance for such applications. Because the energy absorption properties depend significantly on the type of the lattice, five truss-lattice structures with three defined relative densities of material are investigated here. The specific energy absorption is derived under the presumption that the lattice structures are not permanently damaged but return to their original state after some recovery. To guarantee that sustainability, all specimens are manufactured by SLA printing of a soft silicone-like material. A modified Split-Hopkinson pressure bar setup is used to apply the impact on the lattice structures and the energy absorbed by the structures’ reversible deformation is derived from the measured strain pulses coupled with high-speed imaging. It appears that convex lattice structures are the most effective for energy absorption under fast and strong compression.