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.

Prediction of Cylinder Wall Velocity Profiles for ANFO Explosives Combining Thermochemical Calculation, Gurney Model, and Hydro‐Code

“…fracturing of cylinder wall and leaking of gas products, axial expansion of products, wall thinning and hardening, etc. [17, 36]). This is the reason why the detonation energies calculated by thermochemical codes are always higher than experimentally determined Gurney energies at the same expansion ratio.…”

“…), which are not considered in the Gurney model. Souers and Minich [36] gave a detailed analysis of cylinder test corrections. They listed five types of corrections that must be considered, with the wall thinning and work hardening being most important.…”

Propagation Characteristics of Explosion Wave and Explosion Gas in Blast-Hole

“…Te slitting pipe and blast-hole were made of steel, constitutive model used the Steinberg-Guinan strength model and the Mie-Gruneisen equation of state. Te shear modulus G is shown in the following formula [26]:…”