Self‐healing study of impact damage in carbon fiber/epoxy composites based on hybrid polyamide nanofibers

Abstract This research aims to investigate the low‐velocity impact (LVI) response and self‐healing performance of carbon fiber composite laminates (NL) containing staggered hybrid polyamide nanofiber veils. Carbon fiber‐reinforced polymer (CFRP) composites are widely used in many industries, but they are sensitive to LVI damage and there is a lack of research on repair, which restricts their development. In the research, NL samples were prepared, and four impact energies of 6.6, 9.4, 12.2, and 15.0 joules were selected. Ultrasonic C‐scan detection, microscopic observation and mechanical property tests were carried out. The results show that the NL samples have smaller damage areas and degrees, indicating that the veils enhance the impact resistance; the damage repair efficiencies of the NL samples at different energies are 48.3%, 36.2%, 29.7% and 16.8% respectively; when the impact energy is lower than 13.9 J, the flexural strength of the repaired NL samples can be restored to more than 80% of the original strength. These results are of great significance. The improvement of the impact resistance of composites by hybrid polyamide nanofibers can solve the problem of CFRP's sensitivity to LVI damage, and the self‐healing ability provides a new approach to damage treatment, having broad application prospects in aerospace, shipbuilding and other industries. Highlights Hybrid veils enhance impact toughness, reducing damage area and severity. Veils enable self‐healing, repair impact damage, and enhance reusability. Repair efficiency is higher at lower impact energy levels.