Investigation on Dynamic Mechanical Properties of GF / PEEK Thermoplastic Composites Considering High Temperature and Strain Rate Effects

ABSTRACT In this paper, the dynamic response of glass fiber reinforced polyether ether ketone (GF/PEEK) thermoplastic composites under the simultaneous action of different temperature and strain rate conditions was analyzed by combining the Hopkinson compression rod impact experiment. The results showed that the yield strength, peak stress, and specific energy absorption of GF/PEEK decreased significantly with increasing temperature, At the same temperature, increasing the strain rate can enhance the yield strength, peak stress, specific energy absorption, and fracture strain of GF/PEEK. However, with the increase of temperature, the strain enhancement effect of yield strength was stronger, while the strain enhancement effect of specific energy absorption was weaker. From the microscopic scale, an increase in temperature will soften the PEEK matrix and increase the viscoelasticity of the matrix, destroying the stress transfer efficiency. An increase in strain rate will significantly affect the interfacial properties of the GF/PEEK composites, resulting in fiber debonding. The strain rate exerts a strengthening effect on the yield strength, and this effect becomes progressively more pronounced with increasing temperature. In contrast, the strengthening effect of strain rate on energy absorption gradually diminishes as the temperature rises.