Flexural and impact response of sandwich panels with Nomex honeycomb core and hybrid fiber composite skins

This study examined the flexural and impact responses of sandwich panels with honeycomb core and hybrid fiber-reinforced composite skins. The influence of laminate composition and thickness on these mechanical properties was investigated. Carbon, glass, and Kevlar fibers were employed in various combinations to fabricate the composite skins. The findings revealed a general trend of increasing flexural strength, modulus, and toughness with rising laminate thickness. However, the laminate configuration exerted a significant influence. Configurations with a higher carbon fiber content exhibited superior strength but reduced strain (ductility). Conversely, configurations incorporating glass or Kevlar fibers demonstrated enhanced ductility at the expense of strength. Overall, configurations utilizing dry carbon fabric skins achieved the highest flexural strength and toughness, while the combination of carbon and glass fibers offered a desirable compromise between strength and ductility. Regarding impact resistance, configurations with solely carbon fibers initially showed the best performance. However, configurations employing a combination of carbon and glass fibers exhibited a noteworthy increase in impact strength with increasing laminate thickness. This observation suggests that the inclusion of glass fibers alongside carbon fibers provides a well-balanced combination of strength and energy absorption capability.