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Terminal ballistic performance of high-strength projectiles penetrating into metallic targets is mostly concerned by both weapon and armor designers. Most existing works are concentrated on the rigid-eroding penetration regime, and limited studies have addressed the rigid-deforming-eroding penetration regime. In this paper, nineteen shots of hemispherical nosed D6A steel projectiles penetration test on 5A06-H112 aluminum targets is conducted with a wide range of velocities (696 m/s–1870 m/s). The non-monotonic dependence of depth of penetration (DOP) on the impact velocity is observed, which successively corresponds to the three penetration stages, i.e., rigid projectile penetration, deforming projectile penetration without eroding and eroding projectile penetration. Then, for the non-monotonic rigid-deforming-eroding projectile penetration regime, the applicability of the existing six classical theoretical models for both rigid and eroding projectile penetrations is evaluated. Furthermore, the transition velocities (the upper limit of rigid penetration and the lower limit of eroding penetration) are discussed and an empirical judgement criterion for the occurrence of non-monotonic dependence is proposed. Finally, by conducting the dynamic compression test, quasi-static tension test under varying temperature, etc., the Johnson-Cook model parameters for the present target and projectile are calibrated and validated by numerically simulating the present test. [ABSTRACT FROM AUTHOR]

Decades before Newton’s Principia ushered in the age of modern science, Aristotelian physics faced a serious challenge against its weakest point, in the quest to construct a new theory of projectile motion. Yet how were such new principles of motion conceived, without reference to an established theory of mechanics? This paper explores the conceptual space between the rejection of Aristotle’s physics and the appearance of Newton’s physics in which people such as Harriot and Galileo sought new ways to understand mechanical phenomena. This paper seeks to show that both Harriot and Galileo looked to the (early seventeenth-century) zeitgeist of accepting the law of reflection as a law of oblique projection-rebound for all material bodies, for their foundational (non-Aristotelian) conceptual resource. The kinematics and dynamics of light’s compound, oblique motion had been developed over centuries within optics, and constituted the ‘ideal’ resource for novel analyses of oblique projectile motion. Whereas Harriot’s inclusion of air resistance restricted the generalizability of optical principles to his simplest case, the upright parabola, Galileo’s idealized analysis of projectile motion in a vacuum represented all cases of projectile motion as upright parabolas. He was thus able to generalize these optical principles to projectile motion per se. [ABSTRACT FROM AUTHOR]

Abstract: The evaluation of ballistic resistance of steel targets is important due to its direct application to the safety of defense protective structures such as bunkers for military personnel, shelters for arms and explosives as well as safety of nuclear containment against missile impact. Experiments on penetration of 23mm hard projectiles into mild steel plates were performed for 500mm square plates with 30, 50, 60, and 150mm total thicknesses. Results for ballistic limits obtained from existing empirical and analytical relations are compared with those from experiments. In addition, numerical simulations to predict the experimental results were made. Erosion (cell removal) criteria were established in order to realize simulation. Effect of the erosion strain value for which cells are removed on the prediction of penetration into steel plates was investigated. The numerical results show that erosion strain value has a significant effect on the prediction of perforation into steel plates. [Copyright &y& Elsevier]

Abstract: In this paper, the ballistic performance of double-layered steel plates of different materials impacted by blunt- and ogival-nosed projectiles is experimentally investigated by a gas gun. The ballistic limit velocity for each configuration is obtained and compared on the investigation of the effect of the order of layers and the nose shape of projectiles on the ballistic resistance of targets. The experimental results showed that the ballistic limit velocities are higher for the double-layered plates of the upper layer of high strength and low ductility material and the lower layer of low strength and high ductility material than the configuration of the opposite layering order. Moreover, the ballistic limit velocities of ogival-nosed projectiles are significantly smaller than those of blunt-nosed projectiles. Furthermore, the keep integrity ability of ogival-projectiles is obvious stronger than that of blunt-nosed projectiles, and also the blunt-nosed projectiles lose some mass and their length shorten, but the loss of mass and length of ogival-nosed projectiles are tiny that can be neglected. The differences in the ballistic limit velocities between various impact conditions can be related to the transitions of perforation mechanisms and failure models of plates and projectiles. [Copyright &y& Elsevier]

Highlights: [•] The effect of layering depends on the strength and nose shape of projectiles. [•] The change in strength leads to the failure of projectiles. [•] The strength of projectiles affects the ballistic resistance of targets. [•] The number of layers affects the ballistic resistance of targets. [•] The different layering effect due to the transitions of failure models of targets. [ABSTRACT FROM AUTHOR]

The capability of conventional air gun lead pellets (diabolo pellets) to cause severe injuries or fatalities even at low kinetic energy levels is well documented in medical literature. Modern composite hunting pellets, usually a metal core (made of steel, lead, zinc, or a zinc and aluminum alloy) encased in a plastic sleeve, are of special forensic and traumatological interest. These projectiles are advertised by the manufacturers to discharge at higher velocities than conventional air gun pellets, thus generating very high tissue-penetrating capabilities. Lack of experimental data on these uncommon air gun projectiles induced this work. Ballistic parameters of 12 different caliber .177 (4.5 mm) composite pellets, discharged from two spring-piston air guns (Weihrauch HW 35, Webley CUB) and three pneumatic air guns (Walther LGR, Walther LG400, Walther LP300), were investigated using a ballistic speed measurement system and compared to a conventional diabolo pellet (RWS Meisterkugel) as reference projectile. Although overall results were inconsistent, for some projectile-weapon combinations (particularly spring-piston air guns), a significant change of the kinetic energy (−53 up to +48 %) to the reference projectile was observed. The data provided in this work may serve as a basis for forensic investigation as well as traumatological diagnosis and treatment of injuries caused by these uncommon projectiles. [ABSTRACT FROM AUTHOR]

The stress-strain state (SSS) of projectiles is investigated when a high-speed projectile enters water and interacts with barriers protected by a water layer. Experimental investigations are carried out using a high-speed ballistic setup. Calculations are performed within the framework of mechanics of continuous media for an elastic plastic model of a solid with allowance for fracture and hydrodynamic water model. Depending on the projectile speed, different SSS regimes are observed: from small deformed at a speed of ≈1 km/s to fractured at a speed of ≈2 km/s. Calculation technique allows distances in water to be determined at which the metal barrier can be punched for the inertial model. [ABSTRACT FROM AUTHOR]

Abstract: An analytical model has been developed in this paper for perforation of ceramic/multi-layer woven fabric targets by blunt projectiles. In previous Chocron–Galvez analytical model the semi-angle of ceramic conoid is constant and the strain rate effects are also neglected in the stress–strain behavior of the yarns and only strain energy absorbed by the yarns is considered. In this paper which is an improvement to the Chocron–Galvez analytical model for modeling the fragmented ceramic conoid, the Zaera–Sanchez-Galvez analytical model has been used and the semi-angle of ceramic conoid has been modified. For modeling the back-up woven-fabric material and deformation of yarns during perforation, the kinetic and strain energy of yarns has been determined. In the stress–strain relation of yarns, the effect of the strain rate is considered. Furthermore, a failure model based on the energy absorbed until failure by woven fabric is also used. Residual velocity, velocity–time history of projectile, residual mass of fragmented ceramic conoid, penetration depth until failure of yarns and energy absorbed by woven fabric are all estimated by new analytical model. Velocity–time history of the projectile shows a good agreement with the Chocron–Galvez numerical model. Also, near the ballistic limit velocity, prediction of residual velocity of new model is better than Chocron–Galvez analytical model. [ABSTRACT FROM AUTHOR]

Abstract: We have studied the sequence of events that occurs when a high-speed projectile (from 960ms−1 to 1480ms−1) penetrates a vessel filled with toxic liquid. We find that prior to liquid ejection several well-defined phases occur, including the phenomenon known as the “hydraulic ram.” Then a catastrophic tank failure leads to liquid ejection and fragmentation. This paper focuses on this phenomenon and explains how it can be related to the initial conditions of the target. [Copyright &y& Elsevier]

Abstract: In this research an armor material with constant thickness has been studied. The armor consists of two layers: one is a boron carbide ceramic and the other is Kevlar 49 fiber composite material. By using Ansys/Lsdyna software, the ballistic limit velocity of this armor has been obtained and the Heterington equation (optimum thickness of layers) has been verified for constant thickness of the armor. In this research, mechanical properties of Kevlar 49 under different strain rates are utilized and showed that consideration of the strain rate is very important for the simulation of penetration process. Results from the model have confirmed the validity of the Chocron–Galvez analytical model. Moreover, the projectile velocity prediction, especially at high velocity, shows a good agreement with numerical simulations. Finally, normal and oblique impacts of projectile to armor have been simulated and compared. The results show that the ballistic limit velocity of armor increases under oblique impact conditions. [Copyright &y& Elsevier]

The present article deals with the development of a finite element modelling approach for the prediction of residual velocities of hard core ogival-nose projectiles following normal impact on mild steel target plates causing perforation. The impact velocities for the cases analysed are in the range 818-866.3 m/s. Assessment of finite element modelling and analysis includes a comprehensive mesh convergence study using shell elements for representing target plates and solid elements for jacketed projectiles with a copper sheath and a rigid core. Dynamic analyses were carried out with the explicit contact-impact LS-DYNA 970 solver. It has been shown that proper choice of element size and strain rate-based material modelling of target plate are crucial for obtaining test-based residual velocity. The present modelling procedure also leads to realistic representation of target plate failure and projectile sheath erosion during perforation, and confirms earlier observations that thermal effects are not significant for impact problems within the ordnance range. To the best of our knowledge, any aspect of projectile failure or degradation obtained in simulation has not been reported earlier in the literature. The validated simulation approach was applied to compute the ballistic limits and to study the effects of plate thickness and projectile diameter on residual velocity, and trends consistent with experimental data for similar situations were obtained. [ABSTRACT FROM AUTHOR]

Projectiles of sintered tungsten alloy were fired directly at two kinds of steel target plates. The microstructures near the perforation of a medium, 0.45% carbon steel target plate can be identified along the radial direction as: melted and rapidly solidified layer, recrystallized fine-grained layer, deformed fine-grained layer, deformed layer and normal matrix. The adiabatic shear bands cannot be found in this intermediate strength steel. The microstructures along the radial direction of perforation of 30CrMnMo steel target plate are different from that of the medium carbon steel. There was a melted and rapidly solidified layer on the surface of the perforation, underneath there was a diffusing layer, and then fine-grained layer appeared as streamlines. Several kinds of adiabatic shear bands were found in this higher strength steel; they had different directions and widths, which were relative to the shock waves, as well as the complex deformation process of penetration. The deformation of the projectiles was rather different when they impacted on target plates of medium carbon steel and 30CrMnMo steel. The projectile that impacted on the medium carbon steel target plate was tamped and its energy dissipated slowly, while that which impacted on the 30CrMnMo steel target plate was sheared and the energy dissipated quickly. [ABSTRACT FROM AUTHOR]