Cylinder Test Correction for Copper Work Hardening and Spall

Abstract

As a basis for the corrections to be discussed, an analytical equation is first presented for calculating detonation energy densities from copper wall velocities in the Cylinder test. Steinberg-Guinan work hardening is sufficient for the Cylinder problem, between 1 and 60 GPa, with a change of Yo to 0.10 kJ cm−3 for annealed copper. An air gap correction was the first to be applied, which is a function of the initial air gap width and the tilt angle of the cylinder. Irreversible heat loss was also found to be a small error. Spall is calibrated using new copper gun shot data and this energy is also small. The model up through work hardening agrees with the code, which does not contain heat loss or spall, both of which equal the error of repetitive calculation. The effect of the many additions to the original Gurney energy is shown.