环氧树脂玻璃钢的动静态拉伸力学特性

To systematically study the mechanical properties of glass fiber reinforced plastics, the stress-strain curves and corresponding mechanical parameters of glass fiber reinforced plastic with strain rates of 0.001–0.1 s⁻¹ and 1128–1840 s⁻¹ were obtained by material testing system (MTS) and split Hopkinson tensile bar (SHTB). The results show that the glass fiber reinforced plastic exhibits significant strain rate strengthening effect under dynamic loading. Therefore, the dynamic increasing factor was introduced to describe the strengthening effect of strain rate on mechanical properties of glass fiber reinforced plastics. Scanning electron microscopy (SEM) was used to observe and analyze the damaged section, and it was found that the fiber bundle was flatly fracture under dynamic loading, rather than failed by pulling out under static loading. In addition, the results show that the fracture toughness of the fiber-matrix interface under dynamic tensile loading is higher than that under static loading. Finally, based on the dynamic tensile mechanical response of glass fiber reinforced plastic, a nonlinear tensile constitutive model considering damage was established by introducing the macroscopic damage accumulation. Compared with the experimental results, the model as a whole can be used to characterize the dynamic tensile mechanical response of glass fiber reinforced plastic.