Lightweight design for additively manufactured joint structures of UAV wing based on topology optimization

To achieve multi-objective synergistic optimization among lightweight characteristics, high strength, and additive manufacturing feasibility for the joint structures of the large-scale unmanned aerial vehicle (UAV) wing, a synergistic design method integrating topology optimization with static iterative analysis was innovatively proposed under self-supporting process constraints. Based on the characteristics of selective laser melting (SLM) technology, the topology optimization of the wall panel of the Al-Mg-Sc-Zr high-strength aluminum alloy joint was performed by using the variable density method, namely SIMP. A process constraint of an overhang angle θ ≥ 45° was firstly 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 manufacturing feasibility. By finite element analysis verification, the optimized joint’s mass was reduced by 13.78%; the maximum equivalent stress decreased from 183.251 MPa to 175.451 MPa (a reduction of 4.4%) with a more rational stress distribution; the maximum deformation of 0.079 mm still meets the deformation limit of 0.1 mm. The results show that the simultaneous improvement of lightweighting and load-bearing property is realized, providing an innovative approach and practical basis for the “design and manufacturing integration” of UAV load-bearing components.