Compressive behavior of stretching-dominated, bending-dominated, and auxetic 3D-printed metamaterials

Abstract

This research experimentally investigates the compressive response and energy absorption efficiency of seven lattice geometries representing stretching-dominated, bending-dominated, and auxetic topologies. The specimens were standardized to a relative density of 0.2 and manufactured using vat-photopolymerization with a high-performance tough resin. A comprehensive manufacturing protocol was developed, involving an optimized 45-degree build orientation and a 65-degree thermal maturation cycle to ensure maximum cross-linking and dimensional fidelity. Quasi-static uniaxial compression tests were performed using a Shimadzu AGS-X2 system to characterize the load-displacement behavior and extract empirical failure data for each topology class.

The experimental results identified a significant performance hierarchy where the Chiral and Re-entrant architectures exhibited the highest peak strengths, departing from the classical assumption that only stretching-dominated lattices excel in this metric. Concurrently, the Chiral architectures demonstrated superior energy absorption, achieving Specific Energy Absorption (SEA) values exceeding 2200 J/kg due to their stable crushing plateaus. One-way ANOVA and Tukey HSD post-hoc testing confirmed that these differences in peak force and SEA are statistically attributable to lattice topology rather than experimental variability. The study provides insight into the influence of lattice topology on compressive strength, deformation behaviour, and energy absorption under standardized manufacturing conditions.