Q235钢单层板对平头刚性弹抗穿甲特性研究

采用撞击实验和理论模型对单层金属板的抗侵彻性能进行了研究,分析了靶体厚度对抗侵彻性能的影响。通过对比撞击实验和理论模型计算结果,验证了理论模型和参数的有效性。结果表明,采用合适的理论模型能够有效地预测靶板在弹体撞击下的弹道极限。此外,分析了靶体在弹体撞击下的塑性变形总耗能,包括靶板局部变形和整体变形的耗能,同时考虑了靶体材料的应变率效应。在平头弹撞击厚靶的工况中,引入了一个修正函数对靶体厚度进行修正。     

卵形弹侵彻混凝土靶的耦合侵蚀模型

弹体在高速侵彻混凝土介质过程中会出现明显的侵蚀现象,导致弹体发生质量损失和弹头钝化。据已有的实验观察,弹体表面熔化和骨料切削是侵蚀发生的主要机制。该文基于动态空腔膨胀理论并结合弹体表面熔化和骨料切削这两种机制,提出一种耦合两种机制的耦合质量侵蚀模型。该模型通过二维热传导和改进的Rabinowizc磨损理论分别获取弹体表面熔化和骨料对弹体切削而造成的弹体质量损失,通过Johnson-Cook本构将温度和切削两种机制联系起来,进而建立了结合熔化机制和切削机制的耦合质量侵蚀模型。将耦合模型预测的弹体侵彻深度和质量损失率等参数并与实验结果进行对比,对比结果表明模型的理论预测与实验数据有较好的吻合度,验证了该文耦合模型结合熔化和切削机制的合理性。最后,讨论了侵彻过程中弹体的相关运动参数演变过程,为弹体侵彻中侵蚀现象问题的研究提供一定参考。     

钨柱破片对装甲钢的侵彻研究

研究典型柱型破片质量、着靶姿态对装甲钢的弹道极限速度(V₅₀)的影响规律,可为战斗部毁伤元设计提供有效的参考数据。通过弹道冲击试验获取了长径比为1,质量5 g的钨柱在0°和90°着靶姿态下对10 mm装甲钢的V₅₀。试验得到钨柱破片纵向正侵彻10 mm装甲钢的V₅₀为745 m/s,横向正侵彻10 mm装甲钢的V₅₀为761 m/s,钨柱破片在侵彻过程中,破片被横向镦粗,破片头部受靶板挤压磨蚀,形成不规则蘑菇头状翻边。基于试验数据的单一性,通过数值模拟获取了不同着靶姿态下3种典型钨柱(3 g, 5 g, 8 g)对10 mm装甲钢板的V₅₀,并探索了着靶姿态和破片质量对V₅₀变化的影响规律,对比试验与数值模拟结果,两者相对误差在10%左右。研究发现,不同着靶姿态下,钨柱破片侵彻装甲钢的V₅₀存在波动区间,破片纵向正着靶时V₅₀最小,破片以40°～60°着靶姿态角着靶时V₅₀最大,钨柱破片V<...     

大装填比弹侵彻钢筋混凝土实验研究

设计了一种薄壁弹体,采用YOUNG方程预估该弹体侵彻混凝土靶板的侵彻深度,采用SAMPLL程序预估轴向过载.运用LS-DYNA软件分析弹体的侵彻过程,对材料力学性能进行实验研究.通过在φ130 mm气炮上的一系列弹体侵彻钢筋混凝土靶实验,考核了弹体的结构强度和侵彻深度.结果表明:弹体在低速侵彻钢筋混凝土靶板时结构不会发生破坏,300 m/s速度下具备侵彻贯穿600 mm钢筋混凝土层的能力.     

UHMWPE球面层合板弹道侵彻性能研究

进行了超高分子量聚乙烯(UHMWPE)平面层合板、平面夹芯结构以及球面夹芯结构的弹道侵彻实验研究,发现凸球面结构的抗侵彻能力低于平面结构,根据实验现象对球面结构初始曲率的不利影响作了初步分析.应用DYTRAN软件对不同曲率的UHMWPE层合板弹道侵彻进行了数值仿真,分析了层合板曲率对弹道性能的影响规律,认为曲率对层合板变形的限制作用以及由此导致的应力集中是造成抗侵彻能力下降的主要原因.     

分层对TC4钛合金板抗平头弹撞击失效特性的影响

使用Abaqus/Explicit有限元分析软件,开展平头弹撞击不同厚度双层TC4钛合金板数值模拟,研究双层TC4钛合金板撞击失效特性与失效模式随厚度变化规律及机理.通过对比撞击试验与仿真结果,验证数值模型和参数的有效性.在此基础上与等厚度单层TC4钛合金板的抗侵彻性能进行对比,结果表明,对于12.68 mm直径的平头...     

抗破片侵彻钢/芳纶纤维叠层复合结构优化设计方法

针对抗破片侵彻用新型钢/芳纶纤维叠层复合结构优化设计,基于4 mm钢板+12 mm芳纶纤维叠层复合结构、5 mm钢板+10 mm芳纶纤维叠层复合结构抗7.5 g FSP型破片弹道极限速度试验分析,进行了同工况下破片侵彻叠层复合结构的数值仿真计算;在验证数值仿真模型基础上,开展了7.5 g与10.0 g破片对4 mm、5 mm钢板叠加6~16mm芳纶纤维板组合成复合结构侵彻数值仿真,获得了相应的弹道极限速度;根据试验现象和数值仿真结果进行了钢/芳纶纤维叠层复合结构抗破片侵彻机理分析;根据此类复合结构的防护特点,以结构最小面密度为目标函数,建立了适用一定破片质量和撞击速度范围的结构参数优化设计模型;采用所提方法进行了抗撞击速度为1100 m/s的10.0 g破片侵彻的钢/芳纶纤维复合结构实例设计,通过试验验证了优化设计方法的合理性和实用性。     

应力状态对水泥砂浆侵彻性能的影响

研制了真三轴应力状态作用下混凝土侵彻实验装置。该装置采用液压伺服控制系统对立方体试件施加三向独立的静载、采用高压气体驱动子弹侵彻试件;同时,试件六个面的动态信号可由六根杆上的应变片记录。以M10水泥砂浆试件为例,研究水泥砂浆在不同的应力状态下的侵彻性能,建立了相应的数据处理方法,对比分析了立方体试件无侧限、单向侧限、双向侧限下侵彻差异,揭示出应力状态对侵彻性能的影响。该研究对防护工程等领域有很好的参考意义。     

MEMS高量程压阻加速度计侵彻双层钢靶性能测试

设计一种MEMS高量程压阻加速度计,利用其组成的弹体测试系统进行双层钢靶实弹侵彻试验,并获得完整的侵彻数据。利用Matlab数据处理软件对其进行处理,获得有效的侵彻数据。试验结果表明,弹体在整个发射、侵彻钢靶过程中,测试系统所测数据误差均小于10%,说明设计的MEMS高量程压阻加速度计性能稳定,可完全满足工程化应用要求,为研究双层介质侵彻特性及控制弹体在特定介质层的爆破技术提供参考依据。     

刚性卵形头弹撞击角度对编织复合材料层合板侵彻特性的影响

利用一级气炮发射卵形头弹撞击2 mm厚度的编织复合材料层合板,撞击角度分别为0°、30°和45°,通过高速相机记录弹靶撞击过程,并获得弹体速度数据。基于拟合公式处理试验数据,计算获取弹道极限,分析撞击角度对弹道极限、靶板能量吸收率及其失效模式的影响规律及机制。结果表明：弹体撞击角度为45°时,靶板弹道极限最高,其次为0°,撞击角度为30°时最小。随着冲击角度增加,层合板损伤形状从菱形逐渐转变为椭球形,损伤面积随冲击速度增加而增大,且45°冲击时层合板损伤面积最大,0°和30°冲击时损伤面积近似相等。弹体初始撞击角度对靶体失效模式存在影响,弹体撞击角度为0°时,纤维断口主要是剪切应力导致的横截面。撞击角度为30°时,纤维断口主要是剪切应力和拉伸应力导致的斜截面。45°斜撞击时,纤维断口主要是拉伸应力导致的横截面。     

Effect of layering on ballistic properties of metallic shields against sharp-nosed rigid projectiles

On the basis of general assumptions that are pertinent to penetration modeling, we investigated the effect of layering of metallic shields on their protective characteristics against sharp-nosed rigid impactors and established/explained a number of general features of the penetration phenomenon. The main results can be formulated as follows: (i) any layering has an adverse effect on protective properties of the shield against perforation, (ii) increasing the number of layers with the same thicknesses impairs protective properties of the shield. These assertions are validated by analyzing results of experiments and numerical calculations available in the literature that allow comparing protective properties of monolithic and layered shields.     

Experimental investigation on the ballistic resistance of monolithic and multi-layered plates against ogival-nosed rigid projectiles impact

In this paper, the ballistic performance of single, two-, three- and four-layered steel plates impacted by ogival-nosed projectiles were experimentally investigated. Thin multi-layered plates arranged in various combinations of the same total thicknesses were normally impacted with the help of a gas gun. Ballistic limit velocity for each configuration target was obtained and compared based on the investigation of the effect of the air gap between layers, the number, order and thickness of layers on the ballistic resistance of targets. The results show that the thin monolithic targets have greater ballistic limit velocities than multi-layered targets if the total thickness less than a special value, and also the ballistic limit velocities of multi-layered targets decrease with the increase of the number of layers. Otherwise, the moderate thickness monolithic targets give lower ballistic limit velocities than multi-layered targets. Furthermore, the ballistic limit velocities of in-contact multi-layered targets are greater than those of spaced multi-layered targets. The order of layers affects the ballistic limit velocities of multi-layered targets, the ballistic resistance of the multi-layered targets is better when the first layer is thinner than the second layer.     

On the ballistic performance of metallic materials

The paper presents a ballistic performance index for metallic armour materials in terms of the commonly determined mechanical properties such as strength and modulus. The index is derived using an energy-balance approach, where the kinetic energy of the projectile is assumed to be absorbed by the elastic and the plastic deformation involved in the penetration process as well as the kinetic energy imparted to the target material during deformation. The derivation assumes two distinct stages to exist during the penetration of the projectile. At the striking face of the armour, the material is assumed to flow radially in a constrained deformation region but longitudinally at the rear surface leading to typically observed bulging of the armour without constraint. The index is validated using the available experimental and empirical data obtained in the case of small arm projectiles for an impact velocity of about 800 m/sec. This index is expected to facilitate the development of metallic armour, since the number of the ballistic experiments can be reduced significantly and only the promising materials need to be considered.     

Effect of joint design on ballistic performance of quenched and tempered steel welded joints

A study was carried out to evaluate the effect of joint design on ballistic performance of armour grade quenched and tempered steel welded joints. Equal double Vee and unequal double Vee joint configuration were considered in this study. Targets were fabricated using 4 mm thick tungsten carbide hardfaced middle layer; above and below which austenitic stainless steel layers were deposited on both sides of the hardfaced interlayer in both joint configurations. Shielded metal arc welding process was used to deposit for all layers. The fabricated targets were evaluated for its ballistic performance and the results were compared in terms of depth of penetration on weld metal. From the ballistic test results, it was observed that both the targets successfully stopped the bullet penetration at weld center line. Of the two targets, the target made with unequal double Vee joint configuration offered maximum resistance to the bullet penetration at weld metal location without any bulge at the rear side. The higher volume of austenitic stainless steel front layer and the presence of hardfaced interlayer after some depth of soft austenitic stainless steel front layer is the primary reason for the superior ballistic performance of this joint.     

Effect of buttering and hardfacing on ballistic performance of shielded metal arc welded armour steel joints

Quenched and tempered (Q & T) steel closely confirming to AISI 4340 is well known for its superior ballistic performance and hence used in the fabrication of armour vehicles. These steels are traditionally welded by austenitic stainless steel (ASS) fillers to prevent hydrogen induced cracking. Due to weld thermal cycles and under matching fillers, the armour steel joints show poor ballistic performance compared to the base metal. Attempts were made to deposit hardfaced interlayer between ASS weld metals. Though this method yielded marginal improvements in ballistic performance, cracks were observed in between base metal and hardfaced layers. In this investigation an attempt has been made to eliminate these cracks by depositing a soft buttering layer using ASS consumable in between base metal and hardfaced layer. This paper reveals the effect of buttering and hardfacing on ballistic performance of shielded metal arc welded armour steel joints.     

Effect of matrix on ballistic performance of soft body armor

We analyze three-dimensional (3-D) deformations of soft body armor in the form of a clamped rectangular plate impacted at normal incidence by a projectile. Results have been computed by the finite element method, using the commercial software LSDYNA, for the armor with and without a matrix, and in the former case with either perfect or no bonding between the matrix and the yarn. Also, two impact speeds and two polymers, one stiffer than the other, have been considered. Significant contributions of the work include studying 3-D elastoplastic deformations, and delineating the effect of the matrix on the ballistic performance of the armor. It is found that the matrix reduces the maximum deflection of the armor, increases the size of the deformed area, and enhances the reduction in the kinetic energy of the projectile. However, the size of the deformed area is not a good indicator of the energy absorbed during impact. These results are useful for armor designers since the reduction in the maximum deflection should reduce the intensity of injuries to persons wearing the armor. On the other hand the larger deformed area of the armor can increase the possibility of injuries.     

纤维增强树脂基复合材料防弹性能影响因素及破坏机制

以超高分子量聚乙烯(Ultra High Molecular Weight Polyethylene,UHMWPE)纤维、S-玻璃纤维、芳纶1414纤维和杂环芳纶纤维增强聚烯烃(Polyolefin,PO)和水性聚氨酯(Waterborne Polyurethane,WPU)树脂,采用热压工艺制备正交单向无纬(UD)结构复合材料装甲板;通过装甲板弹道极限速度测试,研究了纤维增强树脂基复合材料装甲板防弹性能的影响因素;通过体视显微镜观察装甲板侵彻破坏形貌,分析了纤维增强树脂基复合材料的破坏机制。结果表明:UHMWPE纤维增强PO树脂基复合材料的防弹性能与UHMWPE纤维的强度和模量呈正相关,但纤维模量对复合材料防弹性能的影响随着纤维模量的增大而逐渐变弱;在WPU树脂体系下,四种纤维的防弹性能由高到低依次是UHMWPE纤维、杂环芳纶纤维、芳纶1414纤维、S-玻璃纤维;纤维增强树脂基复合材料装甲板中纤维破坏方式有迎弹面纤维被剪切冲塞、中部被纤维拉伸变形后剪切、背弹面纤维被拉伸断裂,中部纤维拉伸变形是消耗子弹动能的主要方式。     

脉冲电流对疲劳后30CrMnSiA钢组织结构的影响

对在应力控制下预疲劳卸载的热轧态30CrMnSiA钢样品进行高密度脉冲电流处理后，得到了细小均匀的等轴晶组织，晶粒尺寸远小于热轧样品的晶粒尺寸．处理后样品的疲劳寿命显著提高．高密度脉冲电流使疲劳形成的位错产生运动，当刃型位错的距离达到临界距离时，位错发生湮灭，使局部的位错密度梯度增大，在位错密度低的地方发生再结晶形核，使钢发生再结晶．     

A numerical investigation into the influence of fabric construction on ballistic performance

The use of high-performance fibres has made it possible to produce lightweight and strong personal body armour. Parallel to the creation and use of new fibres, fabric construction also plays an essential role for performance improvement. In this research, finite element (FE) models were built up and used to predict the response of woven fabrics with different structural parameters, including fabric structure, thread density of the fabric and yarn linear density. The research confirmed that the plain woven fabric exhibits superior energy absorption over other structures in a ballistic event by absorbing 34% more impact energy than the fabric made from 7-end satin weave. This could be explained that the maximum interlacing points in this fabric which help transmit stress to a larger fabric area, enabling more secondary yarns to be involved for energy dissipation. It was found that fabric energy absorption decreases as fabric is made denser, and this phenomenon becomes more pronounced in a multi-ply ballistic system than in a single-ply system. The research results also indicated that the level of yarn crimp in a woven fabric is an effective parameter in influencing the ballistic performance of the fabrics. A low level of yarn crimp would lead to the increase of the fabric tensile modulus and consequently influencing the propagation of the transverse wave. In addition, it was found that for fabrics with the same level of yarn crimp, low yarn linear density and high fabric tightness were desirable for ballistic performance improvement.