Study on Translaminar Fracture Toughness of Plain‐Woven Carbon/Kevlar Hybrid Composites

ABSTRACT In this study, the translaminar fracture toughness of plain‐woven carbon/Kevlar hybrid composite laminates with different hybridization methods (intralaminar, interlaminar, inter/intralaminar) and ply orientations (0° only, 0° combined with 45°) was investigated. Tests were performed using the compact tension configuration. Digital image correlation was used to characterize the evolution of the surface strain field, and acoustic emission monitoring was employed to track the damage evolution process. The results showed that the intralaminar hybridization mode exhibited a superior toughening effect compared with the interlaminar one. Specifically, the carbon–Kevlar intralaminar hybrid (CK) specimens show a 7% increase in the critical stress intensity factor ( K _Ic ) relative to the carbon fiber composites, whereas the carbon/Kevlar interlaminar hybrid (C/K) specimen demonstrates no significant improvement in K _Ic . With the introduction of 45° ply orientation, a marked enhancement in K _Ic is observed for all specimens. Furthermore, experimental results reveal that specimens containing Kevlar fibers exhibit a reduced crack propagation length, which is attributed to the high ductility of Kevlar fibers, enabling effective suppression of unstable crack growth.