Flexural behavior of 3D printed bio-inspired interlocking suture structures

Additive manufacturing has allowed producing various complex structures inspired by natural materials. In this research, the bio-inspired suture structure was 3D printed using the fused deposition modeling printing technique to study its bending response behavior. Suture is one of the most commonly found structures in biological bodies. The primary purpose of this structure in nature is to improve flexibility by absorbing energy without causing permeant damage to the biological structure. An interesting discovery of the suture joint in diabolical ironclad beetle has given a great opportunity to further study the behavior of these natural suture designs. Inspired by the elliptical shape and the interlocking features of this suture, specimens were designed and 3D printed using polylactic acid thermoplastic polymer. A three-point bending test was then conducted to analyze the flexural behavior of each suture design, while digital image correlation and numerical simulation were performed to capture the insights of deformation process.