Numerical Simulations for Comparative Impact Resistance Analysis of Optimized E-Glass Fiber and Carbon Fiber Composite Wing Structures for UAV Applications

Composite wing structures are widely used in unmanned aerial vehicles (UAVs) because of their high specific strength and stiffness, but they are vulnerable to localized impact events such as tool drops, runway debris and small bird or drone strikes. In many aerospace applications, carbon fiber–reinforced polymers (CFRP) are preferred for their high stiffness and weight efficiency, although they tend to fail in a brittle manner and are expensive. E-glass fiber composites, on the other hand, are tougher and cheaper, but usually considered less competitive in stiffness and impact resistance. This study numerically investigates the impact resistance of optimized E-glass fiber composite UAV wing skins compared with aerospace-grade carbon fiber skins, both supported by balsa-wood cores. A 3D finite element (FE) model of a 600 mm semi-span UAV wing segment was developed in Abaqus/Explicit, with a user-defined VUMAT implementing an orthotropic elastic law and a Hashin-type progressive damage model. A rigid spherical impactor (radius 8 mm) with various mass velocity combinations (0.5 kg at 5000 and 10 000 mm/s, and 1.0 kg at 20 000 mm/s) was used to represent low, medium and high energy impacts. E-glass material sets were defined and gradually improved, within realistic mechanical limits derived from published E-glass/epoxy systems, until a “maximum experimental limit” E-glass configuration was obtained. This optimized E-glass wing skin was then compared with carbon-fiber configurations taken as benchmark aerospace. The comparison is based on peak contact force, penetration or non-penetration, absorbed energy, and damage extent in the skin and sub-structure. The study also proposes a coupon- and sub-component-level experimental programme to validate the numerical predictions using drop-weight impact tests on E-glass and carbon-fiber laminates and on a scaled UAV wing segment. These findings indicate that suitably engineered E-glass composites can be a viable, cost-effective alternative to carbon fiber for impact-resistant UAV wing structures.