Dynamic compression and tensile responses of an epoxy matrix composites at high strain rate

Abstract

To study the dynamic compression and tensile mechanical behaviors of a bicomponent epoxy resin matrix composites, which were filled with a semi-crystalline thermoplastic Polyether-ether ketone (PAEK-C) resin, at high strain rate, the dynamic compression and tensile experiments were carried out on a modified split Hopkinson pressure bar (SHPB) and high speed material apparatus, respectively. Stress-strain curves of the epoxy resin matrix composites were obtained and analyzed. Damage mechanism under high strain rate was characterized through the scanning electron microscope (SEM) observation. Results of the dynamic compression tests indicated that, although the effects of strain rate remarkably influenced the variations in stress, the behaviors of the epoxy resin matrix played a more significant role than strain rate in the determination of the high strain rate. It was reflected through increased ductility of the samples and reduced slope of the stress-strain curves. The dynamic impact tensile tests results show that, PAEK-C fillers exhibited dramatic toughening effect. The increase of the volume fraction of PAEK-C rich phase inevitably forces the crack to overcome more tearing deformation of PAEK-C rich phase. At the same time, the enhancement of plastic capacity may also induce a larger range of cooperative deformation at the crack tip.