Study of Interlaminar Fracture of <scp>CFRP</scp> Laminates Based on Synergistic Toughening of <scp>CNTs</scp> and Nano‐ <scp> SiO ₂ </scp>

ABSTRACT Carbon fiber reinforced polymer (CFRP) composite materials have excellent properties and are widely used in many fields. However, they are challenged by the problem of interlayer delamination. Experimental studies were conducted involving the insertion of polyether sulfone(PEI)/carbon nanotubes (CNTs)/nano‐silicon dioxide (nano‐SiO 2 ) hybrid films into CFRP. The effects of different mixing ratios on toughening were examined using double cantilever beam (DCB) and end notched flexure (ENF) tests. The results showed that, with a 1:1 ratio of nano‐SiO 2 to CNTs, the G IC‐C of mode I fracture toughness increased by 97.54%, while the G IC‐P increased by 62.43%. With a 4:1 ratio, Mode II is the most effective, with a 155.93% increase in G IIC value. A scanning electron microscope (SEM) was used to observe the microstructure of the laminate ply breaks and analyses the toughening mechanism. Hybrid films demonstrate excellent cost‐effectiveness, with production costs reduced by 91.4% compared to traditional materials. This study proposes a low‐cost and efficient method for measuring the interlaminar fracture toughness of CFRP, which has the potential for large‐scale industrial production.