Dynamic tensile behavior of 4-step 3-D braided fabric composites

The uniaxial tensile properties of 4-step 3-D braided fabric E-Glass/epoxy composites at quasi-static and high strain rates loadings have been investigated to evaluate the tensile failure mode at different strain rates.The uniaxial tensile properties at high strain rates from 800 to 2 100 s-1were tested using the split Hopkinson tension bar(SHTB) technique.Tensile properties at quasi-static strain rate were also tested and compared with those in high strain rates.The results indicate that the stress strain curves are rate sensitive,and tensile modulus,maximum tensile stress and corresponding tensile strain are also sensitive to the strain rate.The tensile modulus,maximum tensile stress of 4-step 3-D braided fabric E-Glass/epoxy composites is linearly increased with the strain rate.With increasing of the strain rate,the tensile failure of the 4-step 3-D braided fabric E-Glass/epoxy composite specimens has a tendency of transition from ductile failure to brittle failure.