Fig. 7

Analysis of anisotropic flexibility of the bio-inspired scale armor prototypes. a Schematic diagram of the post-buckling bending experiments. b Left, schematic diagrams of specimens tested in three orientations by varying the angle, φ, which is defined between the loading direction and the width direction of scales. Right, the modeled three φ angles indicated on the chiton’s body. c Experimentally measured and corresponding FE predictions of the force–displacement curves for prototypes with φ of 0°, 60°, and 90°. Photos of the φ = 90° sample at displacement of d 0 and e 60 mm, and f, g corresponding configurations from the FE modeling. The left and right photos in d, e show the front and side views, respectively. The distributions of von Mises stress of the φ = 90° sample from h the front and i the back view. Magnified views of the interaction between adjacent scales at displacement of j, m, p 0 and k, n, q 60 mm for φ = (j, k) 0°, (m, n) 60°, and (p, q) 90° sample, respectively. The red dots indicate the interlocking (contact) among adjacent scales. The von Mises stress distributions within individual scales at displacement of 60 mm due to interscale contact for φ = (l) 0°, (o) 60°, and (r) 90° sample, respectively. s A magnified view of the interlocked scales (indicated by yellow arrows) and t corresponding stress distributions from FE analysis for the φ = 0° sample at displacement of 60 mm.