Topology optimization-based lightweight design for additively manufactured UAV wing joint structures

To achieve multi-objective synergistic optimization among lightweight characteristics, high strength, and additive manufacturing feasibility for large-scale unmanned aerial vehicle (UAV) wing joint structures, this study innovatively proposes a collaborative design methodology integrating topology optimization with static iterative analysis under self-supporting process constraints. Leveraging the characteristics of selective laser melting (SLM) technology, topology optimization of the Al-Mg-Sc-Zr high-strength aluminum alloy joint wall panel was performed using the variable density method (SIMP). For the first time, a process constraint of an overhang angle ≥45° was introduced, with stress not exceeding 180 MPa as the strength objective and a 60% mass reduction as the lightweight constraint, thereby achieving simultaneous optimization of structural performance and manufacturability. Finite element analysis verification showed that the optimized joint's mass was reduced by 13.78%, the maximum equivalent stress decreased from 183.25 MPa to 175.45 MPa (a reduction of 4.4%) with a more rational stress distribution, and the maximum deformation of 0.079 mm remained within the allowable deformation limit of 0.1 mm. This method, through structure-process collaborative design, realizes the simultaneous improvement of lightweight performance and load-bearing capacity, providing an innovative approach and practical basis for the "design-manufacturing integration" of UAV load-bearing components.