Drop-weight impact characteristics of additively manufactured sandwich structures with different cellular designs

Publication date: 5 May 2018
Source:Materials & Design, Volume 145
Author(s): Amer Beharic, Rafael Rodriguez Egui, Li Yang
In the design of sandwich panels with cellular cores for energy absorption, the geometrical effect of the cellular core design has not been investigated in details previously. In this work three cellular core designs, including re-entrant auxetic, octet-truss, and BCC lattice, were experimentally investigated for their performance under low-energy impact as sandwich structures. Samples with different cellular core designs were fabricated by laser sintering additive manufacturing process using Nylon 12 as material, and evaluated by drop weight testing under multiple strikes and at two levels of elevated temperatures (93°C and 121°C). It was found that beside relative densities, the geometrical design of the cellular cores could also significantly influence the impact energy absorption performance of the sandwich structures. It was also found that the impact energy absorption of the cellular structures investigated in this study does not have a significant correlation with either the quasi-static mechanical properties or the temperature. In addition, the auxetic cellular structure exhibits optimal overall energy absorption performance compared to both the octet-truss and the BCC lattice.

Graphical abstract

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