Influence of Unit Cell Parameters on Mechanical Characteristics of 3D‐Printed Cylindrical Metamaterial Structure: A Finite Element and Experimental Study

This study examines how unit cell size affects the mechanical properties of a novel three‐dimensional‐printed cylindrical metamaterial structure made from acrylonitrile butadiene styrene resin via digital light processing additive manufacturing. It addresses key gaps in polymer‐based auxetic cylindrical reinforcements, particularly the lack of systematic parametric studies and experimentally validated models linking unit‐cell geometry to stiffness, strength, specific energy absorption (SEA), and auxetic behavior. The structure features a periodic lattice with tunable center diameter (CD) (4, 5.5, 7 mm) and width (2, 5, 8 mm), optimizing stiffness, strength, SEA, and auxetic behavior. Nine models were designed, fabricated, and tested via quasi‐static compression and finite element analysis in specialized software, with validation under 6% discrepancy. Width primarily enhances compressive strength (up to 360% increase from 160 to 657 N at 7 mm CD) and stiffness (49 N per mm to 431 N per mm), while CD tunes SEA (87.3 millijoules per gram to 231.6 millijoules per gram). Auxetic properties yield Poisson's ratios from −0.7 to −2.9, promoting radial contraction for stability. Optimal performance, with uniform strain and low stress concentration, is at 4 mm CD and 8 mm width, achieving 72.3 N per mm per gram stiffness per mass. This advances lightweight reinforcements for aerospace, civil, medical, and sports applications, enabling sustainable use through precise fabrication and analysis.