Tensile properties of TZ300 carbon fiber bundles at different strain rates

To investigate the tensile mechanical behavior of carbon fiber tows without matrix confinement under different strain rates, a statistical damage constitutive model of the carbon fiber tow was established based on the Weibull statistical theory of fiber bundle strength. Tensile tests of TZ300 carbon fiber tows at quasi-static ( 2.7\times 10^-4\;\texts^-1 ), intermediate ( 3\;\texts^-1 ), and high ( \text470 s^-1 ) strain rates were systematically conducted using an electronic universal testing machine, a self-developed uniaxial pneumatic impact device, and a Hopkinson tensile bar apparatus. The stress–strain curves at each strain rate were obtained, and the corresponding mechanical response characteristics were analyzed. The results indicated that, within the strain rate range covered in the experiments, the TZ300 carbon fiber tows exhibited brittle fracture behavior, and their tensile strength showed no significant strain-rate dependence, indicating that the material is strain-rate insensitive. The statistical strength characteristics of the fiber tow obey a single Weibull distribution, with the unified Weibull parameters: shape parameter \beta =4.52 and scale parameter \sigma _0\text=4.8\;GPa . The proposed constitutive model can well describe its damage evolution and stress-strain relationship at different strain rates. The findings provide a direct basis for establishing simplified, strain-rate-independent numerical models of carbon fiber at the microscale representative volume element (RVE) level, and offer valuable references for promoting the engineering application of textile carbon fiber composites under multi-strain-rate conditions.