The objective of this study was to study the penetration characteristics of tungsten alloy fragments on PCrNi3MoV target plates. Specifically, the penetration of square tungsten alloy fragments of gun steel target plates of different thicknesses were studied using a ballistic gun launching device. Based on the ballistic test results, the relationship between the bulge height of the target plate and the kinetic energy of the fragments was obtained, and the failure mode and process of the tungsten alloy fragments penetrating the steel target were analyzed. Then, the variation on the bulge height of the target plate with the kinetic energy of the fragments was obtained using dimensional analysis. The prediction results were consistent with the test results, and thus, the prediction model can be used in practical applications.

The dispersion distribution characteristics of prefabricated fragments from an improvised explosive device (IED) are essential in defense technology development. To improve warhead design, it is essential to predict a fragments velocity and dispersion distribution accurately. This paper investigates a fragments flying angle from a detonated warhead with a cylindrical charge under a one-end central detonation. A modified formula for calculating the fragment dispersion distribution at each axial position of the warhead was obtained based on experimental data and model analysis. The impacts of the following parameters on the flying angle were considered in the formula: ratio of charge mass to shell mass, charge diameter, axial sparse effect, and relative axial shell position. The formula was verified by experimentation to be suitable for wide applications using different validation samples. Theoretical calculations with the formula show good accuracy in predicting the flying angle of cylindrical-shell fragments, agreeing with experimental data. The proposed model meets the error requirements of engineering applications. This work provides a theoretical foundation for subsequent research on damage effectiveness and IED damage assessment.

Dynamic spatial distribution and killing characteristics of warhead fragments are important topics in the field of weapon effectiveness and protection. However, there is little research on the fragment distribution formed by continuous dynamic attacks of multiple projectiles that explode above the ground. This study analyzes spatial distributions of warhead fragments using witness boards in a rectangular target test. The results show that the fragment distribution of multiple projectiles in continuous dynamic attacks demonstrates a spatial superposition characteristic. The superimposed distribution is the sum of the distributions of two independent fragment distributions. The distribution characteristics are consistent with fragment scattering behavior. Therefore, they can be used to analyze the killing effects of multiple projectiles conveniently. The effects of falling speed, falling angle, and explosion height on the damage range of fragments were explored by a fragment spatial distribution model obtained from experiments. Analysis indicates that the prefabricated fragment distribution conformed to a spatial superposition relationship under dynamic multiprojectile continuous attacks, and the superposition obeyed fragment scattering characteristics. As the projectile falling angle increased at the explosion center, or as the falling height decreased, the positive pressure duration increased gradually. The falling speed had the greatest impact on the specific impulse of overpressure. The falling angle had the greatest impact on the peak value of overpressure. Both the falling angle and the explosion height had the greatest impact on the positive pressure acting time.

Equivalent-thickness conversion among metallic targets is important for vulnerability assessment and protection modelling, but conventional coefficients are often treated as material constants and seldom include fragment morphology. Penetration tests were conducted on 616 armor steel, Q235 steel, and LY12 aluminum alloy using steel spheres, tungsten spheres, and tungsten block fragments. A V50-based database was established, and failure mechanisms were examined from perforation morphology, exit-side SEM, and metallography. A semi-empirical ballistic-limit model was developed from key variables, with a residual correction term to describe the coupled deviation between fragment geometry and target response. The corrected model achieved a mean absolute percentage error of 7.91% and a coefficient of determination of 0.852. The conversion matrices show strong dependence on fragment type. For 616 steel converted to LY12 aluminum alloy, the coefficient increases from 2.50 for spherical fragments to 3.48 for tungsten blocks, giving a morphology-induced deviation of 39.03%. Thus, conversion should be defined by fragment type and target material rather than by a single material constant.