Dynamic tensile properties of carbon fiber composite based on thermoplastic epoxy resin loaded in matrix-dominant directions

The dynamic tensile properties of carbon fiber (CF) composite loaded in the matrix-dominant direction are experimentally determined. In this study, thermoplastic epoxy resin is used as a matrix of the CF composite. A dynamic tensile test is performed using a tension-type split Hopkinson bar technique. The experimental results show that there are not linear relationships between tensile strength and strain rate in case of the 10°, 30° and 45° specimens, although the tensile strength of CF composite, whose matrix is typical thermosetting epoxy resin, linearly increases with the strain rate for all fiber orientation angles. From the fracture surface observation, it is found that the ductile fracture of the matrix can be observed only when 10° off-axis specimen is tested under dynamic loading condition. It is inferred that the softening of the thermoplastic epoxy resin in the vicinity of interface area takes place with increasing strain rate.