Biomimetic Kagome-Gyroid interpenetrating metamaterial for tailoring lightweight and mechanical performance

• Kagome-Gyroid design for enhanced energy absorption and stress distribution. • Optimized geometric parameters balance lightweight and mechanical performance. • Additive manufacturing defects analyzed with strategies for quality improvement. This study presents a novel interpenetrating Kagome-Gyroid (K-G) structure designed to optimize lightweight, high-strength materials. Inspired by natural biomimetic structures, such as the microstructure of butterfly wings and cancellous bone, which are known for their lightweight and strength properties, the K-G structure combines the shear resistance of the Kagome lattice with the high specific strength and stiffness of the Gyroid lattice. The optimized K-G structure demonstrates a 49.5 % increase in specific energy absorption and a 35.6 % improvement in energy absorption efficiency compared to conventional materials, highlighting its superior potential for high-impact applications. Experimental and simulation results reveal that geometric parameters significantly influence the failure and fracture behavior of the structure, particularly affecting its energy absorption characteristics. The study also investigates the distribution patterns of surface roughness and internal defects during the laser powder bed fusion (L-PBF) manufacturing process, highlighting their potential impact on the mechanical performance of the final structure. This novel design provides a promising foundation for the development of advanced materials with superior energy absorption capabilities, making it ideal for high-impact applications in aerospace, rail transportation, and automotive industries, where lightweight and enhanced mechanical performance are critical.