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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]

A laboratory gun that uses compressed gas as its propellant was designed and tested for the study of small projectiles traveling in soils with initial velocities ranging from 50 to 200 m/s. The gun employed the use of air or helium with an electrically triggered, pneumatically piloted, solenoid valve. The triggering system was designed to provide remote activation. A photo gate speedometer was utilized to measure the exit velocity of each projectile. Details of the electro-pneumatic control system are presented in this paper along with the design of the gun assembly and its subsystems. The effects of different design parameters, including muzzle length, projectile mass, propellant type, and volume of compressed gas utilized, on projectile velocity were investigated. Statistical analysis of the gun performance is presented. The gun is currently being used to visualize the fundamental physics of rapid earth penetration in soils, using transparent soils. [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]

• We present a case of a chest gunshot wound with consequent bullet embolism in the left brachial artery. • We discuss the importance of performing postmortem imaging before the autopsy to guide the forensic pathologist in unconventional gunshot injuries. Chest cardio-vascular trauma by a gunshot bullet is less common than head trauma in forensic medicine practice, but still an extremely mortal injury. In front of no exit wound, ballistic trajectory could appear unexplained. We present the case of a 43-year-old man who sustained a gunshot wound in his chest. The entrance was facing the sternum and there was no exit wound. An autopsy completed by forensic radiology (CT-scan of the whole body) showed a wound of anterior pericardial, massive bleeding of pericardia, a wound of the anterior ascending thoracic aorta, and then the bullet embolism to the left brachial artery. Without forensic imaging, the bullet was difficult to find. Bullet embolization should be suspected when there is a gunshot injury to the chest without an exit injury and with no projectile in the area, particularly if the projectile is small. Forensic radiology can help to find bullet projectile: by using whole-body radiography or computed tomography. [ABSTRACT FROM AUTHOR]

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]