To improve the impact resistance of composite materials, this study adopted the structures in the impact region of mantis shrimp appendages as a bionic prototype, designing a composite structure with a rigid outer layer and flexible sinusoidal inner layer. Meanwhile, bionic arrangement was conducted on the fibers in three directions (X-Y, X-Z, and Y-Z planes) within the flexible layer to regulate the crack propagation path during the impact process. Finite Element Method and low-velocity impact tests were carried out to verify the structural effectiveness, analyze the energy absorption mechanism, and investigate the failure modes. Relative to the basic rigid-flexible structure, the brick-and-mortar (Y-Z) and vertical-horizontal alternating fiber (X-Y) models show a 94% and 109% improvement in kinetic energy absorption efficiency, respectively. Additionally, the catastrophic damage in the impact center area caused by crack concentration is significantly reduced. This study confirms that the bionic 3D arrangement of fibers can realize interlayer connection, optimize crack distribution, and enhance energy dissipation, thereby improving the impact resistance of composite materials.

We introduce strategically placed cuts into chiral mechanical metamaterials to achieve strongly anisotropic and static non-reciprocal elasticity in a fully passive architecture. Under loading, the cuts switch between open states that preserve auxetic kinematics and closed contact states that trigger an abrupt stiffness increase, thereby breaking symmetry. By systematically varying the cut topology—the number, placement, and orientation of cuts—we identify regimes with sharp stiffness transitions and pronounced uniaxial and orthogonal non-reciprocity. A topological coding strategy is proposed to program these responses at the unit-cell level. These results establish cut-mediated opening and contact as a general mechanism for designing non-reciprocal mechanical metamaterials.