Investigation on the Strain Rate Sensitivity of Polytetrafluoroethylene
Strain rate sensitivity of polytetrafluoroethylene(PTFE) across strain rate range from 10-3 to 106 s-1 was investigated. For quasi-static state of strain rates from10-3 to 10-1 s-1, the samples were tested using universal material testing machine. The values of compression strength and Young’s Modulus were calculated from the experimental results. And exponential fitting and linear fitting were done to the experimental data of compression strength and Young’s Modulus, respectively. The quasi-static experimental results are compared with Zerillie-Armstrong model for polymers, which shows better agreement at large strains. For 102~103 s-1, the samples were tested using traditional split Hopkinson pressure bars (SHPBs). The experimental result was compared with other test of as-received sample. For 105~106 s-1, the PTFE dynamic pressure experiment was conducted using pressure-shear-plate-impact (PSPI) facility. The polymer-specific Lennard-Jones model was used to analyze the results of ultra-high strain rate.