Effects of temperature on interfacial property of carbon fiber / epoxy resin using single fiber fragmentation energy method

By using single fiber fragmentation test(SFFT) based on WND (Wagner-Nairn-Detassis) energy model, the effects of temperature from ambient temperature to 130 ℃ on the interface fracture energy of two different kinds of sizing carbon fibers/ high temperature cured epoxy resin were investigated, and the effects of the sizing of carbon fibers on the heat resistance of the interphase was studied. Comparing with the short beam shear test, the relationship between micro and macro interfacial properties was analyzed. The results indicate that the interfacial fracture energy of the carbon fiber/epoxy resin decreases at the beginning and then almost unchanges from ambient temperature to 130 ℃. The interface fracture energy of the desized fibers and the effect of temperature are different from the case of the sized fibers, indicating that the sizing plays an important role on the heat resistance of interface. The interlaminar shear strength of the studied carbon fiber/epoxy laminates decreases linearly with increasing temperature, not according with the variation of the interface fracture energy. This is mainly attributed to the differences in the test principles of the two methods and the different damage locations of the interface.