INVESTIGATION OF COMPRESSION MECHANICS OF STRAIN RATE-DEPENDENT FORGED/LAMINATED CARBON FIBER-EPOXY RESIN COMPOSITES

Compression mechanics is one of the basic properties of materials, which determines the application value and scope of materials in engineering. To obtain the compression mechanics of the forged carbon fiber-reinforced epoxy resin composite (FCFREP) and the laminated carbon fiber-reinforced epoxy resin composite (LCFREP), the quasi-static experiments and the split Hopkinson pressure bar (SHPB) experiments were carried out, thereby the stress-strain curves of FCFREP and LCFREP at different strain rates were obtained. The failure modes of the two materials were analyzed by a scanning electron microscope (SEM). The experimental results show that both FCFREP and LCFREP are strain rate-sensitive materials, whose compression mechanics includes a linear elastic stage, a yield stage, and a flow stress stage. The strain rate effect of the FCFREP is only reflected in the plastic stage, and the level of the plastic stress decreases with increase of the strain rate. The strain rate effect of LCFREP is more obvious, and with increase of the strain rate, the elastic modulus increases, the yield point delays, and the flow stress increases. The quasi-static and dynamic constitutive models of FCFREP and LCFREP are described by a piecewise model with strain rate effect, which is in good agreement with the experimental results. The compression mechanics with different strain rates enriches the researches of carbon fiber/epoxy resin composites, and provides a guide for processing and use of engineering materials.