坦克动力舱装甲板红外辐射温度计算分析

建立了坦克动力舱装甲板温度场数值计算模型,针对坦克动力舱装甲板的红外特性进行了理论计算.采用耦合计算方法计算了装甲板的温度场,通过装甲板和空气双向耦合换热计算,并考虑太阳辐射对装甲板温度场的影响,预测了装甲板温度场分布和辐射强度分布.动力舱装甲板温度场的计算结果与测试结果的相对误差小于9.034%,基本满足工程设计的需要.研究结果表明,动力舱顶装甲板是主要辐射源,排气百叶窗和排气管附近顶装甲板是坦克的红外辐射特征明显区域.     

层间混杂复合材料装甲板防弹性能及其防弹机制

为研究层间混杂复合材料装甲板的防弹性能及其防弹机制,采用钢芯弹侵彻层间混杂复合材料装甲板。以超高分子量聚乙烯（Ultra high molecular weight polyethylene,UHMWPE）纤维、对位芳香族聚酰胺纤维作增强纤维,水性聚氨酯（Waterborne Polyurethane,WPU）树脂和环氧树脂（Epoxy resin,EP）作基体,采用热压工艺制备单向（Unidirectional,UD）结构的层间混杂复合材料装甲板。研究混杂比例、防弹面和树脂基体对混杂复合材料装甲板防弹性能的影响以及弹击后混杂复合材料装甲板的破坏形貌,分析混杂复合材料装甲板的防弹机制,并对复合材料装甲板的破坏机制进行了分析。结果表明:混杂复合材料装甲板的防弹性能优于其任一单一纤维复合材料装甲板;WPU的防弹性能要优于环氧树脂;以UHMWPE纤维复合材料充当防弹面时,混杂复合材料装甲板具有更好的防弹性能;纤维拉伸变形和装甲板分层是纤维复合材料装甲板主要的吸能方式。      

自行火炮复合材料防弹机理分析

分析了纺织复合材料和陶瓷的低速冲击性能，并以此为理论基础，剖析陶瓷／复合材料装甲板受弹头冲击时的防弹机理，并建立此过程的动态分析模型，讨论和预测复合装甲的损伤和破坏，为复合材料在复合装甲上的应用和防弹能力预测提供理论分析依据。     

结构形式对舰船舷侧复合装甲结构抗穿甲性能的影响研究

为探讨结构形式对舰船舷侧复合装甲结构抗穿甲性能的影响,采用均质钢板前置和后置复合材料板分别模拟舰船舷侧外设和内设复合装甲结构,结合低速弹道冲击实验,分析和比较了两种结构形式组合靶板的穿甲破坏模式和抗弹吸能能力。在此基础上,得到了球头弹穿透后置组合靶板的剩余速度理论预测公式,并与试验结果进行了比较。结果表明,两种组合靶板中复合装甲板破坏模式的差异主要体现在迎弹面纤维剪切断裂的程度,而均质钢板则由于复合装甲板的影响,呈现出完全不同的破坏模式;后置组合靶板的抗弹吸能能力要大于前置组合靶板;将弹丸穿透后置组合靶板的剩余速度理论预测值与实验结果进行比较,两者吻合较好。     

泡沫铝填充装甲抗射流侵彻的防护性能研究

为提高装甲抗聚能射流侵彻性能,研究新型的泡沫铝填充装甲,运用ANSYS/LS-DYNA 3D有限元分析软件,对聚能射流侵彻泡沫铝填充装甲过程进行数值模拟,对比分析均质装甲和泡沫铝填充装甲的防护性能,结果表明:泡沫铝填充装甲较均质装甲有更好的防护性能。通过运用正交分析法研究前置靶板厚度、靶板材料、泡沫铝厚度、泡沫铝密度对装甲防护性能的影响,得到最优方案。研究结果对泡沫金属填充装甲的工程应用有一定的参考价值。     

N形装甲板抗穿甲弹侵彻性能数值模拟

面向军用车辆弹道防护需求,针对一种由孔板、斜板和基板组成的N形结构装甲板,进行了其抗7.62 mm穿甲弹侵彻性能的数值模拟分析。在验证数值模拟方法有效性的基础上,仿真了子弹对N形装甲板的侵彻过程并分析了其特殊的抗弹机理;研究了弹着点位置对装甲板抗弹性能的影响,结果表明,弹着点位置的不同会导致穿甲弹的侵彻路径和剩余速度的差异;通过对比贯穿3种构型孔板后弹体的偏转角度和完整性,发现锥形孔板对弹体姿态的改变和破坏更大;通过多组仿真得到了锥形孔N形装甲板的弹道极限。结果表明,与等质量均质钢板相比,锥形孔N形装甲板的弹道极限提高了12.5%。     

装甲防护材料抗侵彻性能研究现状

目的分析装甲防护材料抗侵彻性能的研究现状,为改进复合装甲的结构设计提供参考。方法对装甲防护材料的抗侵彻研究现状进行论述,并对其应用情况进行分析。结果分别阐述了金属材料(装甲钢、铝合金和钛合金)、陶瓷复合靶板以及纤维增强复合材料(玻璃纤维、芳纶纤维和超高分子量聚乙烯纤维)的抗侵彻研究现状,并介绍了其应用情况。结论随着战场环境的日益更新和武器装备的飞速发展,单一的装甲防护材料已难以适应战场环境的不断变化,装甲防护材料将朝着强韧化、轻量化、智能化及多功能化发展。     

陶瓷复合装甲优化设计及弹击后剩余弯曲强度

根据防护要求和防护机制,设计了一种C/C-SiC陶瓷/铝基复合泡沫复合装甲。在确保复合装甲面密度为44 kg/m²的前提下,以弹击后剩余弯曲强度为评价标准,以陶瓷板布置位置、各组成层厚度、泡沫金属中泡沫孔径尺寸为研究因素,设计了三因素三水平的正交模拟优化方案,利用有限元软件ABAQUS模拟了子弹侵彻陶瓷靶板的过程及弹击损伤后复合装甲的弯曲实验过程,预测了剩余弯曲强度,并进行了结构优化。根据数值模拟结果制备陶瓷复合装甲试样,进行实弹打靶和弯曲实验以验证复合装甲试样剩余弯曲强度。结果表明,以MIL-A-46103E Ⅲ类2A级为防护标准,剩余弯曲强度最高的陶瓷复合装甲最优化结构形式为：陶瓷板厚度12 mm、陶瓷板做防弹面板、Al基复合泡沫孔径为4 mm+10 mm的混合;对剩余弯曲强度的主次影响因素排序为：陶瓷板厚度>陶瓷板布置位置>Al基复合泡沫孔径。     

弹性体防弹材料的研究进展

众所周知弹性体材料以其良好的弹性为其性能的主要表现方面,具有较小的密度和较大的断裂伸长率,玻璃化温度一般在室温以下,常态是橡胶态。近几年,弹性体材料防弹性能的研究成为了防弹材料领域新的热点,弹性体对装甲板,防弹头盔,建筑物等的防弹防爆性能有很好的提升。本文从弹性体防弹的机理与应用研究进展展开了论述,也展望了弹性体防弹材料的研究前景。     

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。     

Delamination Controlled Ballistic Resistance of Polyethylene/Polyethylene Composite Materials

We have investigated ballistic response of polyethylene/polyethylene (PE/PE) composites to impact by Uzi bullets. For comparison, limited work was carried out on PE/aramid fiber hybrids and PE fiber/Polycarbonate plate laminates. The plates exhibited an average ballistic resistance, V ₅₀, of approximately 90 m/s per 1 kg/m² area density. In term of the protection level per thickness, the ballistic resistance was 76 m/s per 1 mm. Visual and microscopic examinations identified indentation and delamination as the prevailing failure mechanisms. The delamination, energy calculated on the basis of a simple delamination model considering the fracture surface energy of the matrix, was shown to fully balance the dissipated kinetic energy of the bullet, while the contribution of the fiber fracture process was negligible. This is taken as strong circumstantial evidence for the significant role of this failure process in the ballistic resistance of these composites.     

Determination of Materials for Hybrid Design of 3D Soft Body Armour Panels

In order to optimise the construction of soft body armour panels by hybridization, this study aims to identify materials determination for hybrid panel. Different ballistic characteristics of aramid woven fabrics and Ultra High Molecular Weight Polyethylene uni-directional laminates were investigated through ballistic test and fractorgaphic analysis. With an increasing of total layer numbers in a panel, specific energy absorption of Twaron woven panel shows a decrease trend, and Dyneema UD panel exhibits an increasing trend. Such reverse trend of ballistic performance is due to different failure modes of two materials. According to fractorgraphic analysis, Twaron fabric has large transverse deformation for back layers in a perforated panel. This results in higher energy absorption in back layers. For Dyneema UD, thermal damage is the dominant failure mode, which can result in performance degradation especially for front layers on the strike face. In addition, Dyneema UD exhibits significant advantage of minimize Backface Signature (BFS) and a little higher perforation ratio than that of Twaron woven panels. Based on these findings, an optimized hybrid panel is designed by combing Twaron woven fabric before Dyneema UD. In comparison with other panels with different layer sequences, this hybridization manner exhibited better ballistic performance, including improvement of energy absorption, minimized BFS of the non-perforated panel and reduction of perforation ratio. These findings indicated that material determination for hybrid design should be based on ballistic characteristics of different materials and requirements of different regions in a panel.     

Ballistic limit equations in ballistic and shatter regions

Ballistic limit equations are used to predict the damage of spacecraft subjected to impacts by space debris and meteoroids. This paper presents two new ballistic limit equations for impact velocities in the ballistic and shatter regions, respectively. The methodology used to develop the two ballistic limit equations involves the energy balance law and Cohen's debris cratering model. A very often form for ballistic limit equations based on the crater depth in a semi-infinite target was used for the both equations. The limit velocity between the ballistic and shatter regions was expressed as a non-dimensional equation in this paper. Agreement observed between existing and proposed results confirmed the validity of the presented equations.     

The ballistic performance of metal plates subjected to impact by projectiles of different strength

In this paper, the ballistic performance of monolithic, double- and three-layered steel plates impacted by projectiles of different strength is experimentally investigated by a gas gun. The ballistic limit velocity for each configuration target is obtained and compared based on the investigation of the effect of the number of layers and the strength of projectiles on the ballistic resistance. The results showed that monolithic plates had higher ballistic limit velocities than multi-layered plates for projectiles of low strength regardless their nose shape, and also the ballistic limit velocities of plates decreased with the increase of the number of layers. Moreover, monolithic plates showed greater ballistic limit velocities than multi-layered plates for ogival-nosed projectiles of high strength, and also the ballistic limit velocities of plates decreased with the increase of the number of layers. However, monolithic plates had lower ballistic limit velocities than multi-layered plates for blunt-nosed projectiles of high strength, and also the ballistic limit velocities of plates increased with the increase of the number of layers. 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.     

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.     

An investigation into ballistic performance and energy absorption capabilities of woven aramid fabrics

This paper presents an investigation regarding the ballistic performance of protection panels of different fabric ply numbers used in body armours. Twaron CT 710 type fabric layers of differing numbers are joined by using three stitch types to form the panels and then the panels are subjected to ballistic tests according to NIJ standards. Ballistic performance of the panels is determined by measuring trauma depth and trauma diameter. The energy absorbed by the fabric layers and the energy transmitted to the back of the fabric layers are determined from the trauma depth and trauma diameter values using a different approach. It is shown that the fabric ply number and stitching type have significant effects on ballistic properties and the effect of conditioning is limited.     

Impact response of sandwich plates with a pyramidal lattice core

The ballistic performance edge clamped 304 stainless-steel sandwich panels has been measured by impacting the plates at mid-span with a spherical steel projectile whose impact velocity ranged from 250 to 1300 m s⁻¹. The sandwich plates comprised two identical face sheets and a pyramidal truss core: the diameter of the impacting spherical projectile was approximately half the 25 mm truss core cell size. The ballistic behavior has been compared with monolithic 304 stainless-steel plates of approximately equal areal mass and with high-strength aluminum alloy (6061-T6) sandwich panels of identical geometry. The ballistic performance is quantified in terms of the entry and exit projectile velocities while high-speed photography is used to investigate the dynamic deformation and failure mechanisms. The stainless-steel sandwich panels were found to have a much higher ballistic resistance than the 6061-T6 aluminum alloy panels on a per volume basis but the ballistic energy absorption of the aluminum structures was slightly higher on a per unit mass basis. The ballistic performance of the monolithic and sandwich panels is almost identical though the failure mechanics of these two types of structures are rather different. At high impact velocities, the monolithic plates fail by ductile hole enlargement. By contrast, only the proximal face sheet of the sandwich plate undergoes this type of failure. The distal face sheet fails by a petalling mode over the entire velocity range investigated here. Given the substantially higher blast resistance of sandwich plates compared to monolithic plates of equal mass, we conclude that sandwich plates display a potential to outperform monolithic plates in multi-functional applications that combine blast resistance and ballistic performance.     

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.     

The VXI electronics of the DIAMANT particle detector array

A VXI card designed for the processing of signals from the particle detector array DIAMANT, a CsI(Tl) light charged particle ancillary detector system to the EUROBALL and the EXOGAM gamma-spectrometers, is described. The card provides particle energy, particle-type and time-reference information and is compatible with the existing signal-processing system of EUROBALL/EXOGAM. In order to have full compatibility with the electronics of these spectrometers without sacrificing the performance of the card, some new solutions are used in the signal processing. For particle discrimination three methods can be selected; the ballistic deficit method, the zero-crossing method and a combination of these two methods. The figure of merit of the particle discrimination using the combined method is better than that of the zero crossing or the ballistic deficit method individually. Timing signals for particle–gamma coincidence are derived by a specially designed non-delay-line constant fraction discriminator, which exhibits low rise-time-dependent walk. The card has been tested with EUROBALL. The results of these tests are presented.     

Fragmentation of targets during ballistic penetration events

An analytical target fragmentation model is developed to predict the number of armor debris fragments produced in a ballistic penetration event. The model employs an energy balance to estimate the energy available to propagate cracks in the target material and thus produce an estimate of the mean number of behind-armor debris fragments. The expected number of behind-armor debris fragments agrees well with the results of conventional ordnance velocity target penetration behind-armor debris tests. This analytical fragmentation model and test results were used as the basis for the development of a means of calibrating the parameters of a Weibull statistical distribution function to predict the probability distribution of the number of debris fragments produced in a ballistic impact. It was concluded that the armor fragmentation model was a good predictor of the number of fragments produced in a ballistic penetration event deserving further investigation.