Design and finite element analysis of a bio-inspired cellular airfoil for selective laser melting

Abstract

The development of lightweight aerospace structures with high structural efficiency has increased interest in bio-inspired cellular architectures and additive manufacturing. In this study, a bio-inspired cellular airfoil developed as a candidate architecture for future fabrication by selective laser melting (SLM) is proposed and systematically investigated using finite element analysis. The internal architecture, inspired by the hierarchical structural characteristics of banana stems and spiral shells, was generated through a parametric methodology and integrated into NACA0010 and NACA2412 airfoil profiles. Eighteen configurations were created by varying the position factor (K₁) and scaling factor (K₂), and their mechanical responses were evaluated under bending using an elastic–perfectly plastic material model. The effects of the geometric parameters on load–displacement response, bending stiffness, von Mises stress distribution, and first-yield load were examined. The NACA2412 configurations exhibited bending stiffness values of 84.0–99.9 kN/mm, approximately twice those of the NACA0010 designs (41.2–48.0 kN/mm). The highest stiffness of 99.9 kN/mm was obtained for the NACA2412 configuration with K₁=0.5 and K₂=0.5; however, this design developed a maximum von Mises stress of 360 MPa and an estimated first-yield load of 16.0 kN. In contrast, the NACA2412 configuration with K₁=0.75 and K₂=0.5 achieved a bending stiffness of 90.6 kN/mm, a lower peak stress of 276.7 MPa, and the highest estimated first-yield load of 18.8 kN. These results demonstrate that maximizing structural stiffness alone does not necessarily provide the optimum cellular architecture and that the combined control of cellular size and internal member positioning is essential for balancing global stiffness and local stress concentration. The proposed parametric design framework provides a practical approach for developing structurally efficient bio-inspired cellular airfoils suitable for SLM-based aerospace applications.