Abstract: Insufficient interfacial activity and poor wettability between fibers and matrix are the two main factors limiting the improvement of mechanical properties of Carbon Fiber Reinforced Plastics (CFRP). Owl feathers are known for their unique compact structure; they are not only lightweight but also strong. In this study, an in-depth look at owl feathers was made and it found that owl feathers not only have the macro branches structure between feather shafts and branches but also have fine feather structures on the branches. The presence of these fine feather structures increases the specific surface area of the plume branches and allows neighboring plume branches to hook up with each other, forming an effective mechanical interlocking structure. These structures bring owl feathers excellent mechanical properties. Inspired by the natural structure of owl feathers, a weaving technique and a sizing process were combined to prepare bionic Carbon Fiber (CF) fabrics and then to fabricate the bionic CFRP with structural characteristics similar to owl feathers. To evaluate the effect of the fine feather structure on the mechanical properties of CFRP, a mechanical property study on CFRP with and without the fine feather imitation structure were conducted. The experimental results show that the introduction of the fine feather branch structure enhance the mechanical properties of CFRP significantly. Specifically, the tensile strength of the composites increased by 6.42% and 13.06% and the flexural strength increased by 8.02% and 16.87% in the 0° and 90° sample directions, respectively. These results provide a new design idea for the improvement of the mechanical properties of the CFRP, promoting the application of CFRP in engineering fields, such as automotive transportation, rail transit, aerospace, and construction.

Key words: Carbon fiber reinforced epoxy composites, Owl feather, Bionic feather structure, Mechanical properties