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WANG X , JIANG J W , SUN S J , et al . Investigation on the spatial distribution characteristics of behind-armor debris formed by the perforation of EFP through steel target [J ] . Defence Technology , 2020 , 16 : 119 - 135 . DOI: 10.1016/j.dt.2019.05.016 http://doi.org/10.1016/j.dt.2019.05.016 The behind-armor debris (BAD) formed by the perforation of an EFP is the main damage factor for the secondary destruction to the behind-armor components. Aiming at investigating the BAD caused by EFP, flash X-ray radiography combined with an experimental witness plate test method was used, and the FEM-SPH adaptive conversion algorithm in LS-DYNA software was employed to model the perforation process. The simulation results of the debris cloud shape and number of debris were in good agreement with the flash X-ray radiographs and perforated holes on the witness plate, respectively. Three-dimensional numerical simulations of EFP's penetration under various impact conditions were conducted. The results show that, an ellipsoidal debris cloud, with the major-to-minor axis radio (a/b) smaller than that caused by shaped charge jets, was formed behind the target. With the increase of target thickness (h) and decrease of impact velocity (v0) and obliquity (θ), the value of a/b decreases. The number of debris ejected from target is significantly higher than that from EFP. Based on the statistical analysis of the spatial distribution of the BAD, An engineering calculation model was established considering the influence of h, v0 and θ. The model can with reasonable accuracy predict the quantity and velocity distribution characteristics of BAD formed by EFP. © 2019 The Authors

王昕 , 蒋建伟 , 王树有 , 等 . 爆炸成型弹丸侵彻钢靶的后效破片云实验研究 [J ] . 兵工学报 , 2018 , 39 ( 7 ): 1284 - 1290 . DOI: 10.3969/j.issn.1000-1093.2018.07.005 http://doi.org/10.3969/j.issn.1000-1093.2018.07.005 为研究爆炸成型弹丸（EFP）穿透钢靶后的后效威力，设计了长杆形EFP装置及对45号钢 靶板的侵彻实验。采用X光摄影方法观测EFP穿过靶板后的破片云形态及飞散特性；通过测量靶板后一定距离处验证板上的穿孔，得到靶板后破片数量。从拍摄的脉冲X光照片可以看出：EFP穿透钢靶后形成的破片云形状是截椭圆形，飞散角约50°. 从验证板上的穿孔可以看出：靶后破片可穿透10 mm铝板，破片穿孔分布相对随机，穿孔直径近似呈正态分布特征，破片飞散角与X光观测结果一致；随着靶板厚度增大，破片飞散角均为50°，但靶后破片数量呈先增大、后减小的趋势，即存在靶后破片数量最大化的靶板厚度。从回收到的破片可以看出：靶后碎片由EFP和钢靶碎片共同构成。

WANG X , JIANG J W , WANG S Y , et al . Experimental research on fragments after explosively-formed projectile penetrating into steel target [J ] . Acta Armamentarii , 2018 , 39 ( 7 ): 1284 - 1290 . (in Chinese) DOI: 10.3969/j.issn.1000-1093.2018.07.005 http://doi.org/10.3969/j.issn.1000-1093.2018.07.005 A series experiments that the explosively-formed projectiles (EFPs) penetrate 10-40 mm-thick mild carbon steel (45# steel) were designed to investigate the effect of behind armor debris(BAD) after EFP penetrating into steel target. The morphology and scattering characteristics of BAD are observed by pulsed X-ray photography, and the number and damage ability of BAD are obtained by measuring the perforation on witness target. It can be seen from the pulsed X-ray photographs that the shape of BAD presented as fragments is of partial ellipse with the scattering angle of about 50°. The perforation on witness plate shows that BAD could penetrate 10mm-thick aluminum plate, the perforation distribution is relatively random, and the diameter of hole on witness plate approximately conform to normal distribution. The scattering angle varies little with the increase in the target thickness, while the number of BAD increases first and then decreases, namely there is a target thickness that maximizes the number of BAD. It can also be seen from recovered fragments that EFP and steel target debris together constitute the BAD.Key

XING B Y , ZHANG D J , GUO Z Y , et al . Analysis of the mass of behind-armor debris generated by RHA subjected to normal penetration of variable cross-section EFP [J ] . Defence Technology , 2019 , 15 : 390 - 397 . DOI: 10.1016/j.dt.2018.10.006 http://doi.org/10.1016/j.dt.2018.10.006 Analyzing the mass of behind-armor debris (BAD) generated by Rolled Homogeneous Armor (RHA) subjected to normal penetration of variable cross-section Explosively Formed Projectile (EFP) is the purpose of this paper. So theoretical analysis, numerical simulation and experimental data are combined to analyze the influence of variable cross-section characteristic on the time history of crater radius. Moreover the relationships between time history of crater radius (as well as mass of BAD) and the thickness of RHA (from 30 mm to 70 mm) and the impact velocity of EFP (1650 m/s to 1860 m/s) are also investigated. The results indicate that: 1) being compared to the variable cross-section characteristic is ignored, the theoretical time history of crater radius is in better agreement with the simulation results when the variable cross-section characteristic is considered; 2) being compared to the other three conditions of plug, the theoretical mass of BAD is in the best agreement with the simulation results when the shape of plug is frustum of a cone and the angle between generatrix and bottom is 45° and the axial length of mushroom is considered. © 2018

邢柏阳 , 侯云辉 , 李泰华 , 等 . 爆炸成型弹丸垂直侵彻装甲钢靶后破片动能分析 [J ] . 兵工学报 , 2019 , 40 ( 10 ): 2014 - 2021 . DOI: 10.3969/j.issn.1000-1093.2019.10.006 http://doi.org/10.3969/j.issn.1000-1093.2019.10.006 为获得具有较大动能的靶后破片来源以及轴向位置，开展了爆炸成型弹丸（EFP）垂直侵彻装甲钢的试验和仿真研究。借助经过试验验证的仿真方法，分析不同靶板厚度(30~70 mm)、不同EFP着靶速度(1 650~1 860 m/s)下，某典型EFP垂直侵彻装甲钢板后靶板和EFP产生的靶后破片速度、质量沿轴向的分布规律。结果表明：靶板和EFP产生的靶后破片速度随轴向位置近似呈线性增加，当靶板厚度或EFP着靶速度二者之一固定时其斜率固定，并且破片来源(由靶板或EFP产生)对包络线截距的影响也很小；靶板产生的大质量(>10 g) 破片均分布在破片云中间或者靠近靶板的位置，EFP产生的大质量(>10 g)破片均分布在远离靶板的位置；具有较大动能的靶后破片主要由EFP产生，并位于远离靶板的位置。

XING B Y , HOU Y H , LI T H , et al . Analysis of kinetic energy of behind-armor debris generated during the normal penetration of EFP into armor steel [J ] . Acta Armamentarii , 2019 , 40 ( 10 ): 2014 - 2021 . (in Chinese) DOI: 10.3969/j.issn.1000-1093.2019.10.006 http://doi.org/10.3969/j.issn.1000-1093.2019.10.006 The normal penetration of explosively formed penetrator (EFP) into armor steel is test and simulated to obtain the origin and axial position of behind-armor debris (BAD) with bigger kinetic energy. The axial distribution of velocity and mass of BAD generated during the normal penetration of EFP into armor steel under the conditions of different thicknesses of target (30-70 mm) and different impact velocities of EFP (1 650-1 860 m/s) were analyzed by the simulation method. The results indicate that the velocities of BAD from target and EFP increase approximately linearly with its axial position, the slope of envelope line is also constant when the target thickness or impact velocity of EFP is constant, and the intercept of envelope lines is affected weakly by debris origin (generated by target or EFP); the heavy (>10 g) BADs from target are in the middle of BAD cloud or close to target, and the heavy (>10 g) BADs from EFP are far from target; and the BADs with bigger kinetic energy are generated by EFP and far from target. Key

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