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Flat, hemispherical and ogive-2 nosed mild steel projectiles (10 mm diameter, 100 mm length) were fired at 200 m s{sup -1} into the end face of cylindrically confined dry sand (100 mm diameter, 150 mm length). Projectiles were tracked through the sand using flash radiography and high speed photography. By seeding a horizontal plane of randomly dispersed lead shot (

Constitutive models for brittle materials such as glass can be very complex as they are dependent on strains, strain rates, pressures, temperatures, damage and other parameters. There may also be significant (pressure‐dependent) strength after failure such that the constitutive response is much different for intact material and failed material. A large number of laboratory tests is required to develop a comprehensive constitutive model. Another approach is to develop simple models by using penetration‐velocity data obtained from ballistic experiments. Here various functional forms of simple models (with a limited number of constants) can be used to (computationally) match the penetration velocity over a range of impact velocities. This allows for the determination of the most important parameters and it provides an approximation of the stresses that occur during penetration. This article presents several simple computational models for borosilicate glass, including single‐state models and dual‐state models (that include an intact strength and a failed strength).

We present a model for the steady-state penetration phase of yawed long rods. The projectile-target interaction is comprised of axial deceleration and erosion due to frontal pressure, and lateral deceleration due to cavity expansion pressure. By solving the resulting ODEs through time-stepping, the evolution of the projectile/crater shape is obtained.

It is well known that impact inclination is detrimental to penetration performance for long-rod projectiles into semi-infinite targets. The drop-off in performance, measured as the depth of penetration normalized by the initial projectile length, is generally attributed to interference of the tail of the projectile with the side walls of the penetration cavity. However, little has been done to study the effect of impact inclination on the performance of long rods penetrating finite targets. A reverse ballistic experiment and three-dimensional numerical simulations are used to examine the effect of impact inclination against an oblique plate. In particular, the interaction of the projectile with the plate, to include asymmetric enlargement of the penetration channel and side loading of the projectile, are examined in the simulations, and compared to experimental results.

When a long-rod penetrator impacts a target at a high yaw angle, interference of the penetrator with the sidewall of a crater is the mechanism for the degraded penetration performance. The yawed penetrator is described as a series of cylindrical elements. Using this assumption, the model considers the effective diameters of the penetrator whether or not it interacts with the crater wall and a revised crater profile is calculated with the effective diameters.