Characterization of Prepreg-Based Discontinuous Carbon Fiber/Epoxy Systems

This paper quantifies the elastic behavior and failure response of discontinuous carbon fiber/ epoxy laminates produced by compression molding of randomly oriented preimpregnated unidirectional tape. Flat plates have been successfully molded using manually prepared prepreg charges, and showed a satisfactory degree of randomization. Complex relationships between reinforcement aspect ratio and tensile, compressive, and flexural moduli and strengths are observed. For this particular material system, failure is a matrix-dominated event, with little or no fiber breakage, and it promotes relatively high variation in the measured properties. The high-volume carbon fiber content, combined with an aerospace-qualified epoxy resin, opens up opportunities for more aircraft parts to be made of composite materials, particularly for stiffness-critical components where discontinuous fibers offer performance similar to the continuous quasi-isotropic value.