Energy absorption assessment of recovered shapes in 3D-printed star hourglass honeycombs: Experimental and numerical approaches

This study provides an experimental and numerical evaluation of the energy absorption performance of a 3D-printed star hourglass honeycomb structure with a novel design made from pure and reinforced PLA by chopped carbon fibers and continuous glass fiber. The study further investigates the energy absorption response of this structure after the shape recovery due to thermal stimuli under the quasi-static compressive loading. As an additive manufacturing process, Fused Deposition Modeling is used to produce the specimens with pure and reinforced PLA filament. The difference in the nonlinear response of PLA due to plasticity and damage in tension and compression loading directions, as a feature that helps the shape recovery, is considered in mechanical response analysis using the Finite Element approach. Then, in the obtained results distinguish constitutive laws in tension and compression mechanical properties are employed leading to a failure model using the appropriate algorithm consistent with the experiments. According to the obtained results which reveal good agreement regarding the experimental results, by designing appropriate auxetic configuration selecting suitable geometry parameters, and employing the proper material with diverse properties in tension and compression directions, it is possible to fabricate a lattice structure inherits the shape recovery after the compression deformation which exhibits acceptable energy absorption performance even the second shape recovery.