Impact and Penetration Performance Analysis of Biomimetic 3D ‐Printed Hemispherical Thin‐Shell Composites Inspired by Silkworm Cocoon

ABSTRACT Traditional hemispherical thin‐shell composites suffer inconsistent mechanical properties from non‐uniform fiber distribution. This study uses biomimetic 3D printing with vacuum infusion to fabricate silk‐reinforced shells via a point cloud‐based single‐filament path algorithm, achieving uniform fiber layout. These biomimetic shells (30, 60, 90 g silk) are compared to orthogonal layup shells in low‐velocity impact (1–3 J) and anti‐puncture tests. Impact results: Traditional shells show large damage areas (blocky/pancake cracks), low force (700–1200 N), high displacement, and plastic deformation‐induced curves (low effective stiffness). Biomimetic 30 g shells reduce damage (elliptical/star‐shaped) with improved force/displacement; at 60 g/90 g, damage shrinks further—90 g shells have no back‐side damage at 1–2 J, minor at 3 J, nearing elastic response. Puncture results: Traditional shells exhibit severe through‐cracks (up to 29.8 mm) and low force (510–1000 N). Biomimetic 30 g shells form circular damage with higher force; 90 g shells show no back‐side damage at 1–2 J, only frontal pits at 3 J, minimal displacement, and high elasticity. Superior biomimetic performance arises from multi‐directional fiber stress dispersion and high silk interfacial toughness, enhancing effective stiffness, ductility, and energy absorption.