Defence Technology (May 2022)
Hygrothermal effect on high-velocity impact resistance of woven composites
Abstract
The woven glass fiber reinforced composites (GFRP) subjected to high-speed impact is investigated to identify the hygrothermal aging effect on the impact resistance. Both the hygrothermal aged and unaged glass/epoxy laminates are subjected to different impact velocities, which is confirmed as a sensitive factor for the failure modes and mechanisms. The results show the hygrothermal aging effect decreases the ballistic limit by 14.9%, but the influence on ballistic performance is limited within the impact velocity closed to the ballistic limit. The failure modes and energy dissipation mechanisms are confirmed to be slightly influenced by the hygrothermal aging effect. The hygrothermal aging effect induced localization of structural deformation and degradation of mechanical properties are the main reasons for the composite undergoing the same failure modes at smaller impact velocities. Based on the energy absorption mechanisms, analytical expressions predict the ballistic limit and energy absorption to reasonable accuracy, the underestimated total energy absorption results in a relatively poor agreement between the measured and predicted energy absorption efficiency.