Development of Numerical Model for the Crashworthiness of Additively Manufactured Sandwich Lattices

Abstract

Compared to other materials, cellular solids have superior energy absorption capabilities. Of particular interest within this material category are periodic lattice materials, which – in combination with advances in additive manufacturing technologies – allow not only for repeatable behavior, but also for a high degree of customization. In this paper, the crashworthiness of “sandwich” lattice structures is investigated, using both experimental and numerical investigations. After characterizing the quasi-static mechanical performance of solid nylon-carbon fiber and a solid engineering resin material, the response of single-layer cubic and octet lattices with a relative density of 30% made from those materials was characterized and compared. The response of multi-layer cubic and octet lattices was investigated before finally layering single-layer octet and cubic topologies to form two unique “sandwich” lattices. Stress-strain, efficiency-strain and other crashworthiness parameter data was gathered, and it was found that while the three-layer single-topology lattices were capable of absorbing 9.8 J (cube) and 7.8 J (octet), the designed sandwich lattices were experimentally capable of absorbing more: 19.0 J (octet-cube-octet) and 22.4 J (cube-octet-cube).