Dynamic fracture toughness and failure mechanisms of ZnO whiskers secondary reinforced composites

Quasi-static and dynamic fracture properties and damage mechanism of glass fber polymer composites embedded with different mass percentages of ZnO whiskers are investigated by using an Instron Testing machine and a Split-Hopkinson pressure bar. According to the experimental results and linear fracture mechanics, the quasi-static fracture toughness K_Ic and the dynamic fracture toughness K_Id under various impact velocities of specimens are obtained. Fracture mechanism is investigated by fractography analysis with a scanning electron microscope. The experimental results show that the mass percentage of ZnO_w has little influence on the quasi-static fracture toughness, but a little influence on the dynamic fracture toughness and time of initial fracture point of specimens by the reason of various fracture mechanisms.