Iso-mass finite element assessment of ZE10A magnesium alloy as a lightweight alternative to AA5086 in thin-walled UAV wing structures

Reducing structural mass while maintaining stiffness and stability margins is a key requirement in thin-walled UAV wings. Magnesium alloys offer a density advantage over aluminum alloys, but their lower elastic modulus requires assessment in stability-driven designs. This study evaluates ZE10A magnesium alloy as a lightweight alternative to AA5086 in a semi-monocoque UAV wing using an iso-mass finite element approach, in which the compared configurations are sized to maintain approximately equivalent structural mass while allowing material-dependent sheet thickness. A cantilevered half-span model was subjected to a 3.5 g load case, with spanwise pressure estimated using Schrenk's approximation. Static response and elastic stability were assessed through tip deflection, von Mises stress, safety factor, and eigenvalue buckling analyses. Under the baseline iso-mass condition, increasing ZE10A sheet thickness to 1.5 mm to match the mass of the 1.0 mm AA5086 configuration increased the first buckling load multiplier from 9.48 to 16.20 while maintaining comparable tip deflection. In the ultra-lightweight scenario, ZE10A also showed a higher buckling multiplier than AA5086. Within the assumptions of linear elastic and eigenvalue buckling analyses, the results support the potential of ZE10A for preliminary sizing of thin-walled UAV wing structures governed by elastic stability.