Abstract
The high strain rate (-104/s) mechanical properties of a 152μm grain size OFHC copper were determined from the analysis of ballistic test specimens subjected to the Taylor Test. Deformation was analyzed by two independent techniques, one an analytical method and the second a finite element numerical model. The results from these complementary analyses were combined to construct a high strain rate dynamic stress-strain curve for this OFHC copper. This dynamic stress-strain curve is then compared with conventional quasi-static mechanical test data. When deformed at these high strain rates, the OFHC copper exhibits an increase in the yield strength, the strain-hardening rate and the ultimate dynamic strength relative to their conventional quasi-static values. The OFHC copper results are then compared with high strain rate measurements for high purity 1100 aluminum. This reveals distinct differences of the high strain rate deformation of these two metals. It is suggested that the differences may relate to the ability of the OFHC copper to deform by twinning, whereas the aluminum does not exhibit a twinning mode of deformation.
