4. Conclusions
The strain rate dependency of polytetrafluoroethylene(PTFE) specimens in tensile tests was analyzed. The large deformations were measured using a non-contact optical extensometer. Monotonic tests performed under controlled engineering strain rates were performed. An alternative mathematical model was proposed for predicting the mechanical behavior. It is interesting to note that thesemodelequations can be obtained within a thermodynamic context in a similarmanner to that done by Costa Mattos et al. in [22–25] for different mechanical applications. The proposed model assumes that the material response can be split into two parts. Only three tests performed with different controlled strain rates are necessary to identify all material constants that appear in the theory. The main goal is to use the model to obtain the maximum information about the macroscopic properties of polytetrafluoroethylene specimens in tensile tests performed at room temperature with different strain rates froma minimum set of laboratory tests, saving time and reducing experimental costs.