Impact Response and Damage Tolerance of Hybrid Glass/Kevlar-Fibre Epoxy Structural Composites

The present study is aimed at investigating the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composites with 3 mm thickness and 16 layers of fibre (14 layers of E-glass centred and 2 outer layers of Kevlar) were fabricated using compression moulding technique. The fibre orientation of the Kevlar layers had 3 variations (0, 45 and 60 degrees), whereas the E-glass fibre layers were maintained at 0 degrees orientation. Tensile, flexural, impact (Charpy and Izod), interlaminar shear strength and ballistic impact tests were conducted. The ballistic test was performed using a gas gun with spherical hard body projectiles at the projectile velocity of 170 m/s. The pre- and post-impact velocities of the projectiles were measured using a high-speed camera. The energy absorbed by the composite laminates was further reported during the ballistic test, and a computerised tomographic scan was used to analyse the impact damage. The composites with 45 degrees fibre orientation of Kevlar fibres showed better tensile strength, flexural strength, Charpy impact strength, and energy absorption. The energy absorbed by the composites with 45 degrees fibre orientation was 58.68 J, which was 14% and 22% higher than the 0 degrees and 60 degrees oriented composites.

Automated summary

The study investigated the effect of hybridisation on Kevlar/E-Glass based epoxy composite laminate structures. Composite laminates with different fibre orientations were tested for tensile strength, flexural strength, impact resistance, and energy absorption. Results showed that composites with Kevlar fibres oriented at 45 degrees exhibited superior mechanical properties compared to those with 0 and 60 degrees orientations.