High strain-rate compression behavior of polymeric rod and plate Kelvin lattice structures

The compressive high strain-rate behavior of polymeric Kelvin lattice structures with rod-based or plate-based unit cells was investigated through experimental techniques and finite element simulations. Polymeric 5x5x5 cell geometries were manufactured on the millimeter scale using vat polymerization additive manufacturing tested at low (0.001/s) (1000/s) strain-rates. High experiments performed validated for a viscoelastic split-Hopkinson (Kolsky) pressure bar system (SHPB) coupled high-speed imaging digital image correlation (DIC). Experimental results both strain-rates show formation localized deformation band which more prevalent in relative density specimens experiments. Strain-rate effects strongly correlate base polymer material; bulk specimen demonstrated hardening, stiffening, decreased fracture strain under dynamic loading. Results mechanical failure properties energy absorption depended exhibited distinct scaling between geometry type (rod, plate) loading rate. plate-lattices inferior to rod-lattices; however, there exists critical given property (17%–28%) below outperform rod-lattices similar mass. explicit simulations showed good agreement trends modes observed