Manufacturing and testing of CFRC sandwich cylinder with zero-Poisson's-ratio Kevlar meta-honeycomb core layer

A carbon fiber reinforced composite (CFRC) sandwich cylinder with over-expanded honeycomb core (OHC) layer was designed and manufactured to get a lightweight sandwich cylinder meanwhile remaining a relatively simpler fabrication process , as the meta-honeycomb with zero-Poisson's-ratio can be freely curled into a cylindrical structure without saddle warping. Uniaxial compression and free vibration experiments were performed to reveal the strength and stiffness of the cylinder. Due to the rapid stiffness change at the ends, the damage occurs near the end with a horizontal crack. Skin fracture controls the final failure of the cylinder, and the load carrying capability (LCC) is a bit stronger than the referenced cylinder. Material validation analysis, theoretical formulas and imperfection FEM simulation methods were carried out to characterize the failure process. Although the LCC is affected by the local failure at the end, this cylinder shows a much easier manufacturing process and excellent stiffness. Free curling to form a sandwich cylinder.