Tensile Properties of 3D-Printed Porous Bouligand Structured Polymer Plates

The unique architectures of natural Bouligands enable low-density materials to achieve high strength and toughness. This paper concerns the tensile properties of porous Bouligand-structured polymers (PBSP) inspired from the dactyl plunger of snapping shrimps. Samples were stereolithographically printed from Tough 2000 resin with pitch angles ranging from 10–90 and fiber spacings of 0.5–1.25 mm, producing porosities of 0.29–0.48 and apparent densities of 0.56–0.78 g/. Tensile tests were conducted following ASTM D638-22 and were complemented by finite element analysis as a means of analyzing deformations against stress distributions. Tensile modulus and strength both vary non-monotonically with pitch angle, peaking at 30 and partially recovering at 90, while reduced fiber spacing (0.5 mm) provides a consistent improvement in load transfer, delivering 35%–40% higher strength than highly porous (1.25 mm) counterparts. Additionally, the specific properties show respectable stiffness-to-weight and strength-to-weight efficiency with a near-linear scaling between specific modulus and strength. Ashby charts reveal that PBSPs fill a low-density band in which they simultaneously exhibit 2–10 higher stiffness and 10–50 higher strength than typical polymeric foams and approach the specific performance of lightweight fiber-reinforced composites. The hybrid experimental-numerical study presented here establishes a foundation for the optimization of tensile properties in PBSPs, and demonstrates the tunability of mechanical behavior through geometric design.