Study on the strengthening and toughening design of the interlayer interface of GO-based bionic nacre composites and its optimization mechanisms

Inspired by the mineral bridge between hard phase layers of natural nacre, this paper investigates the mechanical properties and optimization strategies of GO-based bionic “brick-mortar” structural composites with interface modification by CNTs. After selectively combining CNTs with GO sheets of different sizes, four biomimetic composites with the same structure but different distributions of strong, medium and weak interfaces were obtained. A comparative study on the mechanical property tests and the finite element simulation results of the samples revealed that the difference in the distributions of different strength interfaces within the material/structure have a significant impact on their localized interfacial failures and subsequent crack extensions, making the deflection of cracks more inclined along the weak interface. Further analysis showed that the targeted and focused optimization of dangerous interfaces with low interfacial bond strength and high stress levels within the material is an effective way to improve the mechanical properties of bionic “brick-mortar” structural composites. The results of the above study will provide useful guidance for the interface optimization and lightweight strengthening and toughness design of composites.