A Visco-hyperelastic Model for the Thermo-mechanical Behavior of Polymer Fibers

A visco-hyperelastic model for the thermo-mechanical behavior of polymer yarns is presented. The model assumes that the stress in a yarn during uniaxial deformation results from the superposition of strain rate hardening effects and the softening caused by filament damage. The filament damage accounts for the fracture of polymer chains and the failure of inter-chain bonds. The constitutive model was implemented in the finite element method as a 1D rope element, and was applied to the study of nylon 6.6 and Kevlar ^® 29 behavior. Numerical simulations of fabrics subjected to ballistic impact were performed, and the model is shown to predict the fabric penetration resistance and the deformation characteristics during the dynamic event.