Mechanical model of bio-inspired composites with sutural tessellation

Architectured composites with sutural tessellations across all length scales are found in the armor systems of many fauna and flora species in nature. These composites are typically composed of relatively stiff building blocks articulated via compliant wavy suture seam, showing a remarkable jigsaw-puzzle-like sutural tessellation. Inspired by these interesting natural architecture materials, bio-inspired designs of composite plates with hexagonal, diamond and rectangular building blocks and triangular suture tessellations were developed. Generalized closed-form analytical expressions for the effective stiffnesses along major axes of symmetry of these designs were derived and finite element (FE) simulations were performed to verify the analytical solution. Suture tessellation was shown to be essential in determining the mechanical properties of the composite plates. The influences of suture waviness, suture dominancy, the shape of the building blocks and the stiffness ratio of the suture tessellation were evaluated. The results provide design guidelines for widely tuning the mechanical properties of the biomimetic composite plates via tailoring suture tessellation.