Bioinspired dual-phase composite metamaterial for customized deformation behavior and performance characteristic

Nature has provided a wealth of unexpected inspiration for the innovative design of dual-phase composite metamaterials, typically consisting of a matrix phase (MP) and a reinforcement phase (RP). This design allows for the simultaneous enhancement of mechanical properties and regulation of deformation processes in these materials. The phase boundary sliding effect of magnesium nanocrystals, the hierarchical cauliflowers and interpenetrating hierarchical nanocages inspired this study three different design methods for dual-phase composite metamaterials. Through systematic design and finite element analysis, we investigated the mechanical properties of various metamaterials under quasi-static loading conditions. Results indicated that increasing the connectivity, phase boundary area and continuous distribution characteristics of the reinforcement phase were the effective approaches in improving the mechanical properties (e.g. 96.90 % increase in specific stiffness) and energy absorption characteristics (e.g. 67.70 % increase in energy absorption) of the metamaterials. Besides, without changing the basic lattice, introducing the interpenetrating lattice at the specific positions could effectively regulate the deformation processes and failure modes, and improve stiffness (e.g. 19.01 % increase) and energy absorption (e.g. 27.33 % increase). This study offered a novel pathway to customize mechanical behavior through bioinspired dual-phase design, which would markedly expand the design space for metamaterials.