▎ 摘 要
Temperature-dependence mechanism of composites under dynamic loadings is essential for designing the aircraft with harsh operation environment. In this work, the dynamic compression mechanical behavior of graphene oxide modified epoxy (GO-epoxy) was systematically investigated over the temperature range from 298K to 423K under the loading strain rate of 5000 s(-1). The results indicate that the compression properties of GO-epoxy are sensitive to the strain rate and temperature. The yield strength of pure epoxy and GO-epoxy under dynamic loading were twice those under quasi-static loading. The strength gradually decreases as the temperature increases, but the temperature stability of GO-epoxy is significantly improved compared to the pure epoxy. The addition of GO helps to inhibit the movement of the molecular chain, suppress the stress softening, prevent the evolution of the micro-cracks and then increase the thermal stability of epoxy. The high speed photograph combined with the digital image correction (DIC) method indicates that GO improves the impact resistance of epoxy at different temperatures and the interfacial interactions contribute to this strengthening mechanism. A modified temperature and rate-dependent empirical constitutive model was developed to describe the dynamic behavior of pure/GO epoxy. The fracture morphologies show the difference failure modes between the GO-epoxy and the pure epoxy. This work on the temperature dependent dynamic behavior of GO modified epoxy could provide guidance for understanding the dynamic strengthening and thermal softening behaviors of nano-reinforcing composites.