Perforation of fragment simulating projectiles into goat skin and muscle

Abstract

This study has produced data for skin perforation velocities and generated algorithms describing velocity versus predicted DoP into muscle for three standardised projectiles, which will be used to improve the fidelity of future injury models. 20% gelatin was demonstrated to accurately reproduce the retardation of the 1.10 g FSPs into goat muscle but the addition of a skin simulant will be required to accurately predict DoP for FSPs less than 1.10 g.

The challenges in developing a finite element injury model of the neck to predict the penetration of explosively propelled projectiles

“…The use of freshly killed animal surrogates in conjunction with pre-ballistic and post-ballistic firing CT scans will enable a numerical model of this surrogate to be built. Testing is most likely to be undertaken with goats or pigs as these animals have the greatest amount of evidence for ballistic testing to date; the skin of goats in particular is believed to be closest to human in terms of projectile retardation 34. Animals would be slaughtered humanely using a Schedule 1 method as approved by the Home Office with testing starting as soon after death as possible to ensure that the material properties of the tissues through which the projectile passes are as close to that of a live subject as possible.…”

“…This tissue simulant enables the incorporation of projectile factors and produces depths of penetration using both 0.49 and 1.10 g cylindrical FSPs comparable with that found in goat34 and pig muscle 35. Measurements made using high speed photography of these FSPs penetrating gelatin will also enable the dimensions of the temporary cavity to be incorporated into the model.…”

Injury representation against ballistic threats using three novel numerical models

“…This model represents the effects of individual projectiles by predicting retardation of the projectile and producing a ‘ wound tract ’, whose dimensions depend on projectile type, size, impact velocity and obliquity. The algorithms are based on experimental testing using physical models, as well as standardised gelatine, a tissue simulant validated in reproducing aspects of projectile effects in animal muscle 2 3. This method cannot however currently predict the weapon/target interaction in other tissue types, in particular bone, as this relationship will be highly complex, needing to reflect the varying densities of different bones with the resultant effects on ricochets and secondary bone fragment formation 20…”

“…When comparing the effects of different ballistic projectiles, two broad categories of models are generally used 1. The first, and still the most common, are physical models, which encompass animal surrogates and inert simulants such as gelatine 2 3. The second category is numerical models, in which computer simulations are used to represent the weapon target interaction 4.…”

Equations for depth of penetration of projectiles

“…Breeze et al 1 analysed experimental data on how far fragments penetrate into 20% gelatin and goat tissue. Theory may assist interpretation.…”