Study on the mechanism of penetration of tungsten alloy fragments into bullet proof vests and gelatin composite targets

DOI:	10.11809/bqzbgcxb2023.11.005
Keywords:	impact dynamics; tungsten alloy fragments; bulletproof inserts; ultra high molecular weight polyethylene; ballistic
Abstract:	In order to study the coupling killing mechanism of bludgeoning and penetrating human targets after fragments penetrate bulletproof plates, a test of tungsten alloy fragment penetrating a protective gelatin target is carried out, and the damage characteristics, damage law and fragment energy transfer relationship of the gelatin target caused by the tungsten alloy fragment penetrating the NIJ Ⅲ SiC/UHMWPE bulletproof plate are obtained. A numerical analysis model for fragments penetrating protected gelatin is established, and the reliability of the calculation model is verified by comparison with experiments. Through numerical analysis, the terminal effect characteristic quantities such as the velocity change of fragments, the internal pressure, stress and stress wave changes of the gelatin target after protection are obtained. Experimental and numerical simulation results show that:the kinetic energy required for fragment penetration protection decreases with the increase of fragment mass. The energy transfer rate of fragments penetrating bulletproof plate increases with the increase of mass. The fragment velocity increases from 1 030 m/s to 1 157 m/s, and the maximum diameter of the bludgeoning depression increases by about 30%; the maximum depth of the bludgeoning depression increases by about 65%; while the maximum diameter of the instantaneous cavity of the gelatin target decreases by about 40%. During the fragment penetration process, the closer to the fragment penetration position, the greater the gelatin stress, and the equivalent strain field has a circular distribution. When the fragments do not penetrate the bulletproof plate, the stress wave propagates in the form of spherical waves in the gelatin. During the contact process between the fragments and the gelatin, there is a continuous stress wave output, which is superimposed with the reflected wave reaching the boundary of the gelatin, affecting the pressure change inside the gelatin.
Issue:	Vol. 44 No. 11 (2023)
Published:	2023-11-28
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