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Inspired by the cross-laminated hierarchical structure and flexible interface of high toughness Strombus gigas shell, the "fiber-metal-polymer" laminated composites with different laying modes including cross-laminated structure and interfacial properties were designed, and the corresponding damage and toughening mechanisms were investigated. It shows that the cross-laminated structure, accompanying soft interface modification by metal ultra-thin strip and polymer can optimize the full-field stress distribution and failure behavior, then achieve maximize energy absorption and ensure good strength (ultimate strain and toughness increased to 352% and 127.5%, respectively compared to unidirectional laminated material), which may provide optimization strategies for the design of lightweight composites. [ABSTRACT FROM AUTHOR]

Inspired by the hierarchical structures and flexible interface of natural nacre, a "fiber-metal-polymer" composed "brick-mortar" structural biomimetic materials with different layout modes and interface characteristics was designed. It shows that, compared with the continuous or random arranged short carbon-fiber reinforced composites, the discontinuous short carbon fiber reinforced nacre-like "brick-mortar" ordered structural composites can improve the stress distribution, failure modes and energy dissipation of the materials by optimizing the topological characteristics of "brick" (e.g. length and lap ratio), introducing flexible interfaces, thus realize the optimal combination of strength and toughness. [ABSTRACT FROM AUTHOR]

This article presents a detailed study of the elastic properties of pillared graphene sheet (PGS) reinforced composites. Modeling of several different composite structures using the numerical simulation software ABAQUS. The effects of carbon nanotube pillar distance (PD), pillar length (PL), CNT inclination angle, the volume fraction of PGS and the number of carbon nanotubes per layer in the PGS on the elastic properties of the reinforced composites are analyzed. The simulation results show that as the volume fraction of PGS increases, the Young's modulus E and shear modulus G of the reinforced composites also increase accordingly. The results also illustrate that the Young's modulus E and shear modulus G of the composites decrease as the tilt angle of the CNTs become larger, but increase with the content of CNTs per layer in the PGS. In addition, the PD and PL of CNTs also influence the elastic properties of the composites. [ABSTRACT FROM AUTHOR]

Carbon fiber reinforced polymer (CFRP) grid sandwich structure with four different grid configurations was prepared using the interlocking assembly process in the present work. All test specimens were subjected to quasi-static out-of-plane uniform compression. The equivalent density, height, geometric configuration, and other factors of the structural core layer were analyzed, and their effects on the failure mode, damage mechanism, and energy absorption characteristics of CFRP grid sandwich structure were discussed. The results showed that there are four distinct stages in the load versus displacement curve of CFRP grid sandwich structure specimens subjected to uniform compression, namely, preloading stage, elastic stage, load drop stage, and platform stage. The main failure modes of CFRP grid sandwich structure are the local buckling and compression fracture of the core rib. The failure load, compression strength, breaking absorbed energy, and specific absorbed energy of CFRP grid sandwich structure are positively correlated with the equivalent density of the structure core layer, and negatively correlated with the height of the structure core layer. When the equivalent density of the core layer of the Mixed CFRP grid sandwich structure was increased by 10 kg/m3, the compressive strength and specific energy absorption of the structure increased by about 5.08 MPa and 186.79 mJ, respectively, and when the core layer height was increased by 10 mm, the compressive strength and specific energy absorption decreased by about 12.04 MPa and 67.39 mJ, respectively; The strength and stability of the Mixed CFRP grid sandwich structure are significantly higher than those of the Triangular, Diamond, and Square CFRP grid sandwich structures. [ABSTRACT FROM AUTHOR]

Strombus gigas shell is a natural biocomposite with good strength and extraordinary toughness, inspired by its internal refined hierarchical microstructures, a soft and hard phases composed cross-laminated hierarchical artificial structural composite that reinforced by discontinuous fiber was designed and prepared by 3D printing, and an investigation on the failure behavior and its strengthening and toughing mechanisms was carried out. It shows that the geometric configuration of the crossed-structure will regulate the local stress status in the hard phase and soft interface of the hierarchical structure significantly, and four different failure modes of this structure were proposed. Through the optimal design of the crossed-structure, the internal structure will undergo adaptive adjustment during loading process, then multiple failure forms and energy dissipation modes may burst out together and realize the improved combination of strength and toughness. This result may provide an optimization strategy for the lightweight composites design and additive manufacturing process. [ABSTRACT FROM AUTHOR]

High-performance fiber materials are widely used in aerospace, automobile and other hi-tech fields due to their excellent mechanical properties. Here, inspired by natural organisms, a kind of bionic composite fiber with excellent mechanical properties, consisting of graphene oxide (GO) and thermoplastic polyurethane (TPU), was prepared by wet spinning method. In the composite fiber, the hard GO sheets and flexible TPU were arranged staggered to form a nacre-like "brick-mortar" layered structure. It shows that the strength and toughness of the composite fiber could be effectively improved by regulating the mass ratio of TPU to GO and the modification of their interfacial properties. Further study indicated that the full-field and local stress distribution can be optimized by regulating the proportion between TPU and GO, and the load transfer efficiency can be further improved by modifying the interface between them, then achieve excellent strength and toughness of the composite fiber. These results will provide useful guidance for the microstructure optimization and performance improvement of GO-based composite fiber. [ABSTRACT FROM AUTHOR]