Garam Kim, Rishabh Pammi, Guyuan Zhang, Waterloo Tsutsui
This study investigated the compression behavior and impact energy absorption characteristics of a carbon fiber (CF)-reinforced composite honeycomb core. Composite sandwich structures are widely used in the aerospace and automotive industries because of their high strength-to-weight ratios. While conventional honeycomb cores such as aluminum and meta-aramid paper are commonly used, they present challenges such as corrosion, moisture absorption, and limitations in achieving higher strength-to-weight ratios. To address these issues, a CF-reinforced composite honeycomb core was designed, fabricated, and experimentally evaluated. Corrugated CF composite sheets were manufactured using CF composite prepreg by compression molding and then bonded with adhesive to form the honeycomb core. Composite face sheets were attached to the top and bottom surfaces using a film adhesive to create sandwich structures, which were subsequently machined to appropriate sizes for compression and impact testing. Comparative analysis with conventional meta-aramid paper and aluminum core specimens showed that the CF composite honeycomb core demonstrated superior performance in terms of compression modulus, compressive strength, and strength-to-weight ratio. Additionally, the CF core showed enhanced impact energy absorption, as indicated by higher peak load, reduced indentation depth, and smaller damage extent around the impact site.