Progressive Static Bending Performance and Damage Tolerance of Composite UAV Wings Under Increasing Tip Displacements

The static bending behaviour of unmanned aerial vehicle (UAV) wings fabricated from composite materials is a crucial determinant of structural performance, particularly under progressive deformation demands that span from nominal service loads to severe deflection conditions. This study develops a progressive, displacement-controlled framework to compare the static bending response of hybrid E-glass/epoxy and carbon-fibre-reinforced polymer (CFRP)/epoxy wings, both with Paulownia internal structure, and a full Paulownia baseline, under increasing tip displacements. Finite element simulations capture load–displacement response, stress redistribution, and energy absorption across displacement regimes from −5 to −50 mm. Results demonstrate that CFRP-skinned wings exhibit higher initial stiffness in the elastic regime, whereas E-glass skins provide improved energy absorption and more progressive stress distribution at large displacements. Conversely, Paulownia alone performs poorly under severe bending, confirming the essential role of composite skins for bending load resistance. The findings underscore the importance of displacement regime classification in static bending assessments and suggest that E-glass composites can offer effective, damage-tolerant alternatives to CFRP for UAV wing applications, particularly where large deformation tolerance is required.