Loading rate effect on the shear behavior of the carbon fiber/epoxy interface

Carbon fiber (CF)/epoxy (EP) composites are widely used in structural components. Quasistatic and dynamic shear experiments were designed and conducted to investigate the effect of the loading rate on the shear behavior of the CF/EP interface. Using numerical simulation, the accuracy of the new shear testing methods to test the shear behavior of interface under both quasistatic and dynamic loading conditions was verified. The shear failure stress increases with increasing loading rate, and the failure mode of the CF/EP interface changes from fiber-matrix debonding to almost entirely brittle fracture of the matrix and fiber-matrix debonding. The proposed shear test methods are promising for testing the shear behavior of interface between two kinds of materials or phases, and the shift in the failure mode is a consequence of the effect of the loading rate on the shear behavior of the CF/EP interface.