Experimental investigation of the quasi-static and dynamic compressive behavior of polymer-based 3D-printed lattice structures

Because additive manufacturing (AM) allows the creation of complex structures that can be tailored or optimized based on mechanical and material specifications, it is increasingly used for various applications. Among others, it gives access to new designs of lightweight shields exhibiting good capabilities for absorbing dynamic loads and kinetic energy. In the present work, the quasi-static and dynamic compressive behavior of 3D polymeric lattice structures manufactured by the fused deposition modeling (FDM) process were evaluated. Two different materials were considered: ABS (Acrylonitrile Butadiene Styrene) and Tough-PLA (PolyLactic Acid). First, the tensile quasi-static mechanical properties of precursor filaments and 3D-printed dog-bone specimens were evaluated. Through these tests, it was observed that the printing process and orientation have a significant effect on the mechanical behavior of AM-produced samples. Then, quasi-static and dynamic compressive tests were conducted on AM-produced cylindrical specimens using two distinct printing topologies. The dynamic tests were performed with a split Hopkinson pressure bar (SHPB) apparatus. The results indicated that the compressive strength increases with the loading rate, indicating a strain rate sensitivity of the studied materials. Finally, three different 3D lattice structures were experimentally evaluated against crushing at two different deformation rates. It was noted that the geometrical design and relative densities of these structures have major effects on their energy absorption capability. However, no clear correlation seems to exist between energy absorption capabilities under quasi-static and dynamic loading conditions.