Quasi-static and dynamic tensile properties of large-rupture-strain (LRS) polyethylene terephthalate fiber bundle

In this paper, the effect of the strain rate (1/600, 40, 80, 120 and 160 s⁻¹) on the dynamic tensile mechanical properties of the polyethylene terephthalate (PET) fiber bundle at room temperate (25 centigrade) was studied using an MTS machine and an Instron drop-weight impact system. The experimental results showed that the tensile strength, failure strain, elastic modulus and toughness of the PET fiber bundle specimen were sensitive to the strain rate. The dispersion of the dynamic tensile strength at different strain rates was statistically quantified through a two-parameter Weibull distribution model. To investigate the deformation and failure mechanism of the PET fiber bundle at different strain rates, finite element analysis was conducted based on the Weibull distribution model of the dynamic tensile strength. Not only do the numerical simulations give close predictions for the stress-strain curve of the PET fiber bundle, but they also reveal the fracture process of the fiber bundle that cannot be captured in the test.