Mechanical Response of Four-Star-Honeycomb Hybrid Metamaterial Under In-Plane Loading

This paper focuses on designing and producing a hybrid metamaterial with a relative density of at least 0.59 using additive manufacturing. The metamaterial consists of layers of four-star (A) and honeycomb (B)-shaped unit cells. Three configurations (ABA, AABAA, and AABB) were 3D printed at various layer heights (0.06, 0.10, 0.15, and 0.20 mm). The quality of the printed samples depends on the layer height, with lower heights producing fewer defects and better geometric accuracy. In-plane compression tests were conducted to evaluate the mechanical properties. The stress-strain curves exhibited linear plateau and densification regions, varying across designs and layer heights. The AABB structure, printed at 0.1 and 0.06-mm layer heights, showed the highest peak stress, while the ABA structure exhibited the lowest stress. The AABB structure, with a density of 742 kg/m³, demonstrated the potential for large deformation applications. Visual examination revealed distinct distortion patterns in the unit cells during loading, with the honeycomb cells in the ABA structure experiencing the most significant shape distortion. Overall, this research highlights the potential of hybrid metamaterials for lightweight and large deformation applications. The optimal design and manufacturing parameters can be tailored to achieve specific mechanical properties and performance requirements.