Effect of solution-blown nanofibrous web on quasi-static punch shear test results and quasi-static indentation behavior of carbon fiber-reinforced epoxy matrix composites

This study investigated the effects of the nanofiber interlayer in carbon fiber-reinforced epoxy matrix composites on quasi-static loading behaviors such as quasi-static punch shear (QS-PST), quasi-static indentation (QSI), and short-beam shear (SBS) loading. The solution-blowing technique was used to produce polyamide-6 (PA6) nanofiber with 1 g/m² areal density. A 2×2 twill weave carbon fiber fabric with an areal density of 200 g/m² was covered with solution-blown nanofibers. The vacuum-assisted resin transfer molding (VARTM) method was used to manufacture nanofiber interlayered composites and non-interlayered composites. QS-PS experiments were conducted at three different span to punch ratios (SPR), namely 1.1, 2, and 4. The PA6 nanofiber had a synergetic effect on the composite structure. In the QS-PST experiments, it increased the amount of work achieved by the specimen at rates of 29.5%, 13.5%, and 5.66% for SPR 1.1, 2, and 4, respectively while it provided increases in the maximum force at rates of 15.3%, 15%, and 5.7%, respectively. Additionally, the PA6 nanofiber contributed to the composite material properties determined based on the QSI test including the maximum force, punch crush strength, crush stiffness, and through-thickness modulus at rates of 7.5%, 7.56%, 2.72%, and 5.76%, respectively. Finally, an increase at a rate of 11.43% was determined in the SBS strength of the nanofiber interlayered composite, while it showed an increase in maximum force observed during the SBS experiment at a rate of 12.28%. The enhancements of mechanical properties of structural composites make them more reliable for high technology applications like aerospace, and automotive.