Measurement of the behaviour of high-purity copper at very high rates of strain

Published measurements describing the high strain rate constitutive behaviour of oxygen-free high-conductivity (OFHC) and commercially pure copper are limited and show considerable scatter. To provide additional data, a direct impact compressive split Hopkinson bar was miniaturized to utilize specimens, 640 μm in diameter and 686 and 292 μm in length. This paper describes the design of this apparatus and results for OFHC copper. Good agreement is shown with results from pressure shear plate impact experiments.