Nacre-inspired auxetic interlocking brick-and-mortar composites

We design auxetic 3D interlocking brick-and-mortar composites inspired by nacre - a natural strong and resilient high-performance material. The influences of geometrical parameters and base material properties on their effective elastic properties are systematically investigated by finite element simulations and computational homogenization. The numerical results indicate that the composites exhibit tunable negative Poisson's ratios by properly tailoring the underlying microstructures. It is revealed that the auxetic behavior therein is attributed to the relative sliding between adjacent bricks with waviness, i.e., the sliding mechanism. These materials, with their auxetic properties and high fracture toughness, are well-suited for a wide range of engineering applications, such as serving as robust auxetic materials.