A nonlinear crack bridging model for the composites with curved reinforcement

Both artificial nanocomposites and biological materials typically contain nanofillers with curved forms, which allows them to develop excellent mechanical characteristics and functionalities. In order to measure the fracture toughness of the composites contributed by the bridged reinforcement with curved morphology, a theoretical model based on micromechanics and taking into account the reinforcement's curvature is developed in this study. It is found that the fracture toughness of the composites is more sensitive to the reinforcement waviness rather than its curvature. Larger waviness contributes to higher fracture toughness. By increasing platelet length, volume fraction, and modulus ratio, as well as increasing the interfacial frictional stress after debonding, the fracture toughness of composites is dramatically improved. This study expands our understanding of how reinforcement morphology affects fracture behaviors of composites and offers theoretical insights for elucidating the structure–property relationships of complex micro-structured advanced composites.