Dynamic Fracture Toughness and Damage Monitoring in Hybrid Composites

An experimental investigation is performed to study dynamic mode-I fracture toughness and damage sensing capabilities of hybrid composites using a novel modified split-Hopkinson pressure bar (SHPB) setup. Six different hybrid glass/carbon composites (two interlaminar and four intralaminar) are considered in this study. A modified four probes measurement system and high-speed imaging are used to determine the change in resistance response and dynamic fracture toughness. Furthermore, scanning electron microscopy (SEM) imaging is used to investigate the fracture mechanisms. Mode-I fracture toughness is also determined under static loading conditions to compare with that of dynamic conditions. Results show that G-inter interlaminar composite shows the highest fracture initiation toughness (G IC ) of 741 J/m 2 and 620 J/m 2 under dynamic and static loading conditions, respectively. However, (G45/C45) A intralaminar composite shows better damage sensing capability with a change in resistance of 1168% and 593% for a 40 mm crack growth under dynamic and static loading conditions, respectively. The composites also demonstrate rate sensitivity for both fracture initiation toughness and the peak resistance change during mode-I fracture loading.