A Mechanical Metamaterial for Energy Absorption using Carbon Fiber Composite

• A mechanical metamaterial was designed based on carbon fiber composites . • The structure integrates multi-stable and mono-stable characteristics. • A torsion inhibition method was employed in mechanical metamaterial. • Effect of geometric parameters on energy absorption property were analyzed. • The performance of unit structure in series and parallel arrangement was demonstrated. Mechanical metamaterials are usually prepared using additive manufacturing process, which limits the dynamic tuning of their mechanical properties after preparation. In this study, a mechanical metamaterial was designed using carbon fiber composites, and prepared by hot-pressing process as well as assembled by discrete assembly method. By leveraging the inherent anisotropic properties of the material, a single structure achieved both multi-stable and mono-stable characteristics. A torsion inhibition method based on modular design was employed to inhibit the overall torsion angle of the structure and improve the stability of structures under compression. The mechanical properties of structure under compression and impact were simulated using the finite element method. The simulation results are in good agreement with the experiment data, indicating that the torsion inhibition method effectively reduced the torsion angle. The effects of drilling spacing l , ply angle α , and helix radius r on the mechanical properties were also been studied. Under the multi-stable characteristic of the structure, energy absorption was achieved by overcoming its energy barriers, demonstrating great potential in cushioning and energy absorption applications.