Abstract
A longitudinal compressive modulus of carbon fiber was measured using a single fiber model composite. A single fiber was straightly embedded in an epoxy matrix, and its compression test was performed by means of four point bending test. Young's modulus of the epoxy matrix was reduced intentionally by changing the mixture ratio of epoxy resin/hardener to develop fiber micro-buckling. Two polyacrylonitrile carbon fibers with different longitudinal tensile modulus were provided for the experiment. An E-glass fiber with almost same diameter as the carbon fibers was used as a reference material. The micro-buckling wavelengths of the carbon fibers embedded in the epoxy resin were measured during the compression tests, from which the longitudinal compressive moduli were calculated. Estimated compressive moduli of the carbon fibers were found to be almost the same to each longitudinal tensile modulus.
