A statistical constitutive model for the strength of brittle fiber at different strain rates

A statistical constitutive model, which takes account the effect of strain rate, was presented to describe the stress-strain relationship of brittle fiber bundles. To verify its reliability, tensile tests on two kinds of brittle fibers: glass fiber and SiC fiber, were carried out at different strain rates, and the stress-strain curves were obtained. It was found that the modulus E, the strength sigma(b) and the fracture strain epsilon(b) of these fiber bundles all increase with increasing strain rate. The simulated stress-strain curves, derived from the constitutive model, fit the tested results well, which indicates that the model is valid and reliable.