Optimization, additive manufacturing, and testing of bird-bone-inspired materials for aircraft wing designs

Inspired by the continuous shells and graded porous interiors of natural bird bones, this study presents a framework to design, optimize, and additively manufacture bird-bone-like materials for a new class of aircraft wing designs without traditional components such as ribs, spars, and stiffeners. Additive manufacturing, including fused deposition modeling (FDM), enables the rapid fabrication of these complex bio-inspired geometries with minimal material waste but introduces significant anisotropy due to its layer-by-layer deposition process. We implemented a transversely isotropic material model with Hill’s yield criterion to capture the directional dependence of FDM-printed polylactic acid (PLA). Using the Covariance Matrix Adaptation Evolution Strategy (CMA-ES), the bird-bone-inspired materials were optimized to minimize wing mass while maximizing load-carrying capacity. This framework achieved substantial improvements in structural efficiency, with 48–54 % for wings with lattice-based internal structures and 23–37 % for foam-based internal structures compared to reference designs. Experimental validation through structural testing of 3D-printed wings showed strong agreement with numerical predictions, with differences in effective stiffness and load-carrying capacity within 1.4–3.3 % and 1.2–13.5 %, respectively, of simulated values. The results confirm the effectiveness of this integrated framework for designing lightweight, high-performance bird-bone-inspired materials for aerospace applications.