Richard L. Summers

An analytical expression for the velocity difference between jet particles from a shaped charge

A model was derived to predict the velocity difference between particulated shaped charge jet particles. The model is based on the ‘‘wire drawing’’ formula presented by Kolsky, the plastic instability criterion, and the Zerilli‐Armstrong constitutive equation for face‐centered‐cubic (fcc) materials. The velocity difference expression is strongly dependent on the jet temperature and weakly dependent on the jet strain rate. Calculations were also made using the Johnson‐Cook constitutive model. The velocity difference between jet particles was calculated using several variants of the model. Velocity difference comparisons with experimental data were made for several shaped charge designs with copper liners of various geometries.

Shaped charge jet particulation

An analytical model was developed to predict the breakup time of the jet from a shaped charge liner. The model is based on three presumptions. First, a kinematic expression for the breakup time; second, expression related to plastic stability; and finally, a material‐based constitutive equation relating the stress, strain, strain rate, and temperature. In other words, the jet from a shaped charge linear with particulate when it becomes plastically unstable, and the breakup time will depend on the stress, strain, strain rate, and temperature at failure (particulation).