Self-similar nesting strategy enables lattices achieve dual energy-absorbing plateaus

Abstract

Inspired by natural self-similar nesting (SN) strategy, the basic truss unit simple cubic (SC), face centered cubic (FCC), and body centered cubic (BCC) were regenerated into novel architected SN units, aiming to achieve dual-plateaus and improved energy-absorbing capacity compared to basic truss units. Through compression experiments, finite element analysis, microstructure observation and theoretical calculation, the SN lattices were investigated to explore the influence of the nesting ratio on the compressive responses. The optimal nesting ratio was verified as 0.4 for the unit size of 8 mm and the relative density of 20%, enable SN-SC and SN-FCC achieve the stable and excellent energy absorption capabilities. Furthermore, the underlying mechanism of dual-plateau achieved by SN strategy was revealed that a SN unit can be zoned into a stronger region containing the nested core SC/FCC and a weaker region consisting of exterior nest SC/FCC and mediation BCC. The higher yield strength of the nested core SC/FCC compared to the exterior nest SC/FCC and BCC actually cause the second higher stress plateau and the better failure-resistance for the SN lattices. The improvement effect of SN strategy on SC and FCC units indicates that SN strategy has the potential to be applicable to various strut-based units.