UV Radiation Effects on the Performance of Aerospace Composites

Abstract The aerospace industry increasingly relies on composite materials in spacecraft, satellites, and aircraft due to their superior mechanical properties and non-magnetic nature. However, the effect of ultraviolet (UV) radiation on polymer composites remains underexplored with conflicting reports in the literature. This study examines the flexural properties of E-glass/epoxy composites under varying UV exposure durations and intensities. Results show that UV exposure initially improves mechanical performance, with flexural stiffness increasing by 17% after 48 hours and by 22% at 1300 × 10−3 W/m2. Similarly, flexural strength increased by 10%, rising from 193.90 MPa to 213 MPa after 48 hours and by 15% to 222 MPa at the highest UV intensity. Despite these gains, longer exposure durations (96 hours) showed slight reductions in strength and stiffness, indicating the onset of surface degradation and microstructural damage. These findings reveal that UV radiation has a dual effect: enhancing mechanical properties at moderate exposure while degrading them at extended durations. This study provides insights for optimizing composite material performance in aerospace applications, ensuring durability in UV-intensive environments.