Mechanical behavior of polytetrafluoroethylene in tensile loading under different strain rates

The present work is concerned with the study of the mechanical behavior of polytetrafluoroethylene (PTFE) in tensile tests performed under different strain rates using standard specimens. The strains are measured through a non-contact video extensometer. This procedure is particularly accurate since large deformations are involved. A mathematical model is proposed to predict the mechanical behavior observed in the experiments. The main goal is to predict the stress-strain curve under different strain rates using model equations that combine enough mathematical simplicity to allow their use in engineering problems with the capability of describing complex non-linear mechanical behaviour. The material constants that appear in the model equations can be easily identified from only three tests performed at different constant strain rates. Results from experimental tensile testing were compared with the model predictions showing a good agreement.