Compressive Strain-Rate Tests on Six Selected Materials at Strain Rates From 10⁻³ to 10⁴ In/In/Sec

The results of compressive strain-rate tests on 6061-T6 aluminum, 7075-T6 aluminum, 6Al-4V titanium fully annealed, pyrolytic graphite, lucite, and micarta for rates of loading of 10⁻³ to 10⁴ in/in/sec are presented. A medium strain-rate machine and a split Hopkinson bar apparatus used to conduct these tests are described, and the principle of operation, data-reduction methods, and a critique of techniques are given for each machine. Results of the tests show that the two aluminums exhibit no strain-rate sensitivity over the rates tested. Titanium, lucite, and micarta are rate sensitive with the titanium exhibiting a delayed yield and the lucite and micarta showing viscoelastic behavior. The pyrolytic graphite shows little rate sensitivity below 10 in/in/sec and slight sensitivity above this rate.