The Research on Compressive Properties of Polytetrafluoroethylene at High Strain Rate

The mechanical behaviors of polytetrafluoroethylene (PTFE) in compressive test performed at different strain rates ranging from 10−2 s−1 to 103 s−1 are studied. The experimental results show that the yield strength increases with the increase in strain rate and exhibits a bilinear dependence on the logarithms of the stain rates, but the yield strain decreases with the increase in strain rate. Based on the mathematical model proposed by Nunes and the bilinear relationship between yield strength and strain rate, a modified constitutive model which can describe its complex non-linear mechanical behavior is proposed. The experimental results are in a good agreement with the predicted results of model within 40% of strain.