Compressive behavior of additively manufactured circular-core chiral lattice structures with CNT-reinforced PMMA: a multi-scale analysis.

This study investigates the compressive behavior of additively manufactured chiral lattice panels fabricated from PMMA/CNT nanocomposites employing a multi-scale numerical-experimental framework. The research introduces an enhanced chiral topology featuring circular cores and utilizes a three-phase representative volume element (RVE) model-comprising the matrix, CNTs, and interphase-to determine equivalent mechanical properties. RVE analysis revealed that 0.5 wt% CNT reinforcement offers optimal performance, enhancing Young's modulus and yield stress by up to 70% and 85%, respectively. Incorporating these homogenized properties into finite element (FE) models indicated that the circular-core topology yields a 71.5% increase in peak load and superior plateau stability compared to conventional configurations. Experimental validation confirmed these trends; the enhanced structure reinforced with 0.5 wt% CNT sustained a peak force of 677 N and absorbed energy exceeding 7.7 J, representing a 137% and 54% improvement, respectively over the pristine specimen. Parametric analysis further identified a ligament thickness of 3 mm and a core radius of 3 mm as geometric optima for maximizing load-bearing capacity. The findings demonstrate that the synergistic integration of the novel chiral geometry and nanoscale reinforcement facilitates uniform stress distribution and mitigates local buckling. Consequently, the proposed multi‑scale RVE‑FE framework emerges as a robust design tool for advancing next‑generation lightweight lattice structures aimed at energy absorption and structural protection.