Mechanical behavior of bio-inspired crossed-lamellar microstructures for achieving high-performance composites

Abstract

The remarkable toughness of Strombus gigas shell arises from its microstructure. In this study, inspired by the biologic crossed-lamellar microstructure of Strombus gigas shell, we prepared a novel carbon fiber reinforced polymer (CFRP) composite with inverse-biologic crossed-lamellar structure by replacing the inner and outer layers with the “tough” middle structure. The influences of the alternating arrangement of crossed-lamellar three-layer structure on the mechanical responses, including toughening mechanisms and biological mechanism, were studied. Experimental and numerical results indicated that as burrowing mollusks, Strombus gigas shells require a balance of certain load-carrying capacity and stronger protection function. Meanwhile, the tailored inverse-biologic structure achieved higher load-bearing capacity and stiffness. Additionally, the Bouligand-ply design strategy was proposed as an alternative to the traditional angle-ply design for the crossed-lamellar structure. By changing the laying-up form and pitch angle of the middle layer, a significant improvement in both load-bearing and energy dissipation capacity of the structures was achieved. The paper provides valuable insights for the design of high-performance biomimetic crossed-lamellar structures and holds great potential for the customization of fiber-reinforced composites.