Experiment study on the strain rate behavior of carbon/epoxy composite materials

The strain rate dependent behavior of T300 carbon/epoxy matrix composite in tension was studied by testing two kinds of laminates _S and _S at different rates. The tensile test was carried out on an MTS machine at the quasi-static strain rates of approximately 10^-5~10^-4 s^-1 and the intermediate strain rates of about 10⁰~10¹s^-1. The tensile high strain rate test was conducted with the tensile split Hopkinson bar technique at strain rates of approximately 10²~10⁴ s^-1. The specimens with identical geometry were used in all the tests. The dynamic stress-strain plot was obtained and compared with the quasi-static tensile test result. The results of the study indicate that Carbon/Epoxy composites are strain rate dependent materials. The stacking sequence has a significant effect on the material response. The tensile strength of the composites increases with increasing the strain rate, and the failure strain decreases when the strain rate increases. A constitutive model for characterizing the strain rate dependent behavior of T300/Epoxy composites was derived by simulating the experimental data.