Calculation and Test of Hitting Force of Firing Bullet on the Bulletproof Helmet

In this paper the hit force of firing bullet on bulletproof helmet has been computed and the test device has been described. The device is divided into two parts: 1) The bullet, helmet and mould are in one system, using moment theorem to calculate the hit force; 2) The mould, sensor and support pole are in one system, using the method in reference [1] that measures the dynamic strain and displacement of simulate target of bulletproof clothes. We compute the transfigure energy and momentum energy when hitting the mould, the work done by the sensor and the expend energy of support pole. We get the hit force of helmet using energy balance principle. The result is according with the test and has been used to design the GGK93T bulletproof helmet and other serial products.

Relationships between distribution characteristics of ceramic fragments and anti-penetration performance of ceramic composite bulletproof insert plates

Through quantitative statistics and morphological characterization of ceramic fragments for ceramic composite bulletproof insert plates(CCBIPs),distribution characteristics of ceramic fragments within a specific size range were analyzed for different Armor Piercing Incendiary(API)and shot times.To quantitatively evaluate the effect of energy absorption for ceramic plates,a model of energy absorption during penetration for CCBIPs was established based on statistics of the size distribution of ceramic fragments(SDCF).Variation in the SDCF and its influence on energy absorption for CCBIPs were investigated.The results indicate that the distribution feature of ceramic fragments in the range of 0.25-2.25 mm is Gaussian distribution.Compared with Type 56 of API(56-API),ceramic fragments formed by 53-API with higher kinetic energy possess more quantity and more concentrated distribution,whose average equivalence size decreases by 6.5%,corresponding to increasing by 83.9%of estimated energy absorption.Besides,the ability of CCBIPs to resist the third shot is significantly weakened,whose estimated energy absorption decreases by 58.8%compared with the first shot.More concentrated distribution and fewer fragments are formed after the third shot,the average equivalence size of ceramic fragments increases by 6.9%,which may attribute to the micro-cracks induced by the previous two shots.

Development and application research of light weight heat treated B-grade bulletproof steel

The light weight heat treated B-grade bulletproof steel was developed through composition design and optimization based on multiplex alloying,multiplex micro-alloying design ideas and complex phase structure strengthening theory.The puzzle how to avoid the quenching deformation problem of super high strength thin sheet was solved through heat treatment in a die with a set of cooling system.Such B-grade bulletproof steel plate has fine tempered lath martensite structure.The shooting and certification test results showed that the shoot resistance of B-grade bulletproof steel plate can meet the protection demand of Protection specification for cash carrying vehicles(GA 164—2005).In comparison with B-grade bulletproof steel plate made by one of the companies in Sweden,the weight of the developed B-grade bulletproof steel plate can be decreased by 8 %under the same shoot resistance condition.It will be meaningful for cash truck and anti-hijacking vehicle to realize light weight,energy conservation and emission reduction.

Numerical analysis on the shoot resistance of heat treated light weight B-grade bulletproof steel plates

Bulletproof steel plates are widely used for the safety of special vehicles.This paper mainly researches on the shoot resistance of heat treated light weight B-grade bulletproof steel plates through numerical analysis.Based on the flow behavior of bulletproof steel plates and bullet at various high strain rates,finite element(FE) model has been set up using ANSYS/LS-DYNA software.The simulation results are compared with the shooting results,which show a good consistency and a high reliability.Therefore,the simulation results are efficient approaches and strategies to decide and select the mechanical property and thickness of bulletproof steel plates,saving a lot of work and the cost of experiments.

A Systematic Molecular Dynamics Investigation on the Graphene Polymer Nanocomposites for Bulletproofing

In modern physics and fabrication technology,simulation of projectile and target collision is vital to improve design in some critical applications,like;bulletproofing and medical applications.Graphene,the most prominent member of two dimensional materials presents ultrahigh tensile strength and stiffness.Moreover,polydimethylsiloxane(PDMS)is one of the most important elastomeric materials with a high extensive application area,ranging from medical,fabric,and interface material.In this work we considered graphene/PDMS structures to explore the bullet resistance of resulting nanocomposites.To this aim,extensive molecular dynamic simulations were carried out to identify the penetration of bullet through the graphene and PDMS composite structures.In this paper,we simulate the impact of a diamond bullet with different velocities on the composites made of single-or bi-layer graphene placed in different positions of PDMS polymers.The underlying mechanism concerning how the PDMS improves the resistance of graphene against impact loading is discussed.We discuss that with the same content of graphene,placing the graphene in between the PDMS result in enhanced bullet resistance.This work comparatively examines the enhancement in design of polymer nanocomposites to improve their bulletproofing response and the obtained results may serve as valuable guide for future experimental and theoretical studies.

Study on high speed tension property of B-grade bulletproof steel

In this paper, the high speed tension experiments have been performed on ultra high strength bulletproof steel. The specimen were cut from B-grade bulletproof steel sheet after hard-module quenching with thickness of 2.3 mm. The mechanical properties at strain rates of 0.001 s^-1, 0.01 s^-1, 0.1 s^-1 and 1 s^-1 were carried out on MTSS10, while those at higher strain rates of 200 s^-1, 500 s^-1 and i 000 s^-1 were tested on HTM5020 high speed tension tester and Hopkinson bar. The data from the high speed tension experiments were fitted via Johnson-Cook constitutive equation, and the fracture surface of each specimen was analyzed by scanning electron microscope （SEM）. The results indicate that, the shoot resistance capability of bulletproof steel is closely related to its strength, thickness and flow behaviors under high strain rate. The shoot resistance will be improved in the case of higher strength and better matching between strength and elongation. The Johnson-Cook constitutive equation fitted via experimental data provides fundament to numerical simulation. With the increase of strain rate, the size and depth of dimple trend to decrease and the depth of dimple changes less in steel with lower strength and higher elongation. The SEM analysis of fracture aspect is of benefit for further understanding of deformation and fracture mode under high strain rate.

弹道冲击下石墨烯和聚乙烯改性芳纶织物的钝伤防护性能

芳纶凭借其轻质高强的特点广泛应用于防弹领域。为提高单层芳纶织物的抗钝伤能力,采用热塑性树脂聚乙烯(Polythene,PE)与石墨烯纳米粒子表面改性方法提升芳纶织物的抗钝伤性能。以背衬凹陷为标准,对不同质量配比改性芳纶织物的抗钝伤能力和能量吸收特性进行测试对比。对比结果表明:石墨烯和PE两种改性方法均可提升芳纶织物的抗钝伤能力,其中PE改性方法使得改性织物面密度增加较小但抗钝伤能力显著提升,10%PE的防弹能力和比吸能值较纯芳纶分别提升了18.0%和30.8%;石墨烯改性织物刚性的增加使其低速抗钝伤能力增强,但是过大的纱线间摩擦使其高速防护能力减弱,2%石墨烯粉体为石墨烯改性织物的最佳配比。此外,优化验证得到了2层10%PE和13层的6层正交超高分子量PE无纬布防弹衣组合设计。

吸波/防弹复合材料的研发

采用玻璃纤维布/改性环氧树脂、碳纤维布/环氧树脂以湿法手糊成型工艺制备透波层和反射层,并与吸波浆料浸渍后的芳纶蜂窝芯复合制成电磁屏蔽材料。将电磁屏蔽材料与芳纶防弹板复合制成吸波/防弹一体化材料,该材料可满足GA 141—2010防弹标准要求,在频率2~18 GHz范围的最大反射率可达-25 dB,具有较好的吸波性能。

有限元分析技术在织物力学性能领域的应用

随着计算机和软件技术的快速发展,有限元分析技术展现出越来越大的潜力,已成为纺织服装领域进行力学性能研究的重要手段。为促进有限元分析技术在织物力学性能中的有效应用,更好地解决生产实践中的问题,首先从实验图像和物理几何手段两方面,阐述了目前织物几何模型的构建方法;梳理了织物材料连续模型、离散模型、半离散模型等本构模型的研究进展;其次,归纳了目前常用有限元分析软件的应用领域及优缺点,概括了有限元技术在织物拉伸、撕裂、防弹冲击、弯曲等力学性能领域的应用现状;最后指出当前研究存在模型精度不足、材料参数难确定、边界条件设置困难等不足,后续可以从应用多尺度分析方法、开发高精纺织检测仪、进行多物理场耦合模拟等方面展开研究。研究结果可用于指导生产实践,更好地解决织物力学性能的相关问题。

含损伤的无机防弹玻璃的JH2本构模型

防弹玻璃具有良好的抗冲击性能,能够抵御枪弹、爆炸碎片以及其他高速飞行物体的攻击性威胁,广泛应用于安全防护领域。为探究防弹玻璃的无机玻璃层在冲击加载下的动态力学性能及本构关系,首先,采用电子万能试验机和分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)试验装置,获得了不同应变率下材料的拉伸和压缩力学性能,结果表明,无机玻璃具有明显的应变率效应,材料强度随应变率的升高而增大。其次,借鉴土力学三轴围压试验,设计了适用于本研究的高强围压套筒,测试了完全损伤条件下玻璃颗粒的力学性能,发现其强度明显低于完整状态下无机玻璃的强度。最后,结合试验数据构建了含损伤无机玻璃的JH2本构模型,采用非线性有限元软件LS-DYNA模拟了材料在SHPB加载下的压缩过程,通过对比试验结果与模拟结果,验证了本构模型的有效性。

无压烧结碳化硅防弹陶瓷材料研究进展

随着国际形势不断变化,各国冲突加剧,国防力量的提升是保证国家稳定发展的必要条件,防弹装甲是其中的关键一环。无压烧结碳化硅陶瓷由于制备工艺简单,具有低密度、高硬度、高强度等特性,被广泛应用于防弹装甲领域,其硬度和断裂韧性的高低直接决定防弹性能的优劣。促进烧结致密化以及多相复合烧结等方式是提高无压烧结碳化硅陶瓷硬度和断裂韧性的关键。本文针对无压烧结碳化硅防弹陶瓷材料的烧结助剂、增韧方式、陶瓷装甲的复合形式等方面,总结了近年来无压烧结碳化硅防弹陶瓷材料的研究进展。

防弹衣材料及防护性能研究进展

通过对硬质防弹衣、软质防弹衣、软硬防弹衣以及液体防弹衣防弹机理的研究,厘清研制新型防护材料的需求和发展方向。通过分述高性能纤维复合材料、石墨烯防护材料、聚对苯撑苯并二噁唑纤维复合防弹材料、混杂结构防弹复合材料、无纺布防护材料、液体防护材料的性能特点、结构种类、应用方向、防护效果等,为制作不同功能的防弹衣有效选用不同种类的防护材料提供依据。阐述了各种类型防弹衣的应用前景和发展趋势,充分考虑穿戴者的生理状态、环境变化和袭击威胁等多种情境,概述了现代战争对多功能防弹衣的迫切需求与广泛的应用空间,并结合电子防弹衣、新型智能防弹衣,现代数字化技术不断升级,物联网和智能传感器实时监测技术的未来发展趋势,挖掘和探索防弹衣结构设计、外观设计与内在质量、防护效果的协调作用,实现防弹衣防护效能和穿着舒适美观的统一,为现代新型防弹衣的设计、制造和应用,提供充分的理论支持和实践指导。

直升机复合装甲典型攻角下的防弹能力分析

武装直升机作为战场的战略攻防利器,使用装甲是最典型的防护方式。目前,直升机装甲的防护能力均是以弹体垂直入射时可防护的距离和可防护的最大口径弹种表示,但研究发现,实际状态下弹体几乎不可能以垂直入射的方式实现打击,所以装甲的实际防护能力并未被最大限度地发挥出来。文章通过设计包线试验的方法探究了直升机现用的陶瓷复合装甲在典型攻角下的防护规律,并进行了分析研究,提出了可能的装甲防护力提升设计思路,在倾斜15°的布置方式下,防弹性能可提升19.1%左右。

软质防弹衣中减凹陷材料和防弹层结构的研究

本论文为实现软质防弹衣的轻量化,并减轻子弹冲击对人体造成的非贯穿性损伤,设计了一种新型的减凹陷片和防弹层叠层方式,并通过弹道测试系统进行打靶测试。结果表明:相比单一的减凹陷片材料,采用复合材料加强的减凹陷片,其减凹陷效果更好,并且,复合材料与减凹陷材料的组合方式影响减凹陷效果;防弹层采用防弹单元面密度阶梯递减的叠层方案,能减小软质防弹衣中防弹层的面密度,实现防弹衣的轻量化,并且,防弹层面密度减小的同时,防弹衣的凹陷值不会增大,大幅度提高了软质防弹衣的防弹性能。

新型防弹环氧胶粘剂的研制与性能研究

采用两种环氧树脂、双马来酰亚胺、环氧扩链剂、固化剂、促进剂以及两种增韧剂,研制了系列无溶剂环氧胶粘剂体系,并对其性能进行了综合研究。研究结果表明:(1)4种不同配方的防弹环氧胶粘剂中,JC-4黏度适中,随温度升高而整体下降趋势均匀。当温度达到60℃以上时,黏度在400 mPa·s以内,便于对纤维涂敷。4种配方的环氧胶粘剂反应活性均较高,可在室温下进行固化且不会损伤UHMWPE纤维的性能。(2)4种配方的防弹环氧胶粘剂在中低温区均表现出优异的剪切强度,其中JC-3和JC-4配方的胶粘剂较为优异,在120℃仍具有11 MPa以上的剪切强度,表现出良好的耐高温稳定性,能够满足防弹复合材料对树脂基强度和耐热性基本需求。(3)4种配方的相对介电常数在3.9~4.5之间,均具有良好的介电性能,其中JC-4配方所制的环氧胶粘剂介电常数最低,具有良好的电绝缘性。JC-2、JC-3和JC-4的介电损耗在1.8%以内,表现出较优异的介质损耗稳定性。4种配方的环氧胶粘剂吸水率在0.36%~0.65%之间,均具有优异的疏水性能,其中JC-4配方胶粘剂吸水率最低仅为0.362%。(4)将JC-4配方用作防弹复合材料的胶粘剂,防弹复合材料在射击试验中,未被击穿,背弹面受弹头冲击而凸起,背凸高度为23 mm,能够满足防弹复合材料对胶粘剂的性能要求。

新型高性能环氧防弹胶粘剂的研制

采用两种环氧树脂(多官能环氧树脂SINEP E80、环氧树脂SRTEM-50)与聚砜树脂(SE3940)、环氧扩链剂等,添加多种环氧增韧剂,再加入固化剂和促进剂,制得4种环氧胶粘剂体系,并对其性能进行综合分析。研究结果表明:(1)4种不同增韧剂配比的环氧胶粘剂中,PEJ-3黏度适中,便于涂覆于纤维,且表观活化能较低,固化反应速率较快。(2)4种配方环氧胶粘剂的电容随着频率增加而缓慢下降,其中PEJ-2、PEJ-3、PEJ-4配方胶粘剂的电容在4.6~5.4之间,均具有良好的电容稳定性。4种不同增韧剂配比的环氧胶粘剂,其介电损耗随着频率的增加而增加,在外加电场下,4种配方表现出良好的电气绝缘性能。(3)4种配方的环氧胶粘剂在中低温区均表现出优异的剪切性能。其中,PEJ-3在测试范围-60~190℃仍能保持较高的拉伸剪切强度,该配方具有较好的粘接强度和耐高低温性能,可满足防弹复合材料的树脂基强度及耐热性能的基本需求。(4)4个配方的吸水率均体现出良好的疏水性能,在0.20%~0.60%之间。这一特性使其在需要防水、防潮的场合具有广泛的应用前景。(5)PEJ-3配方复合材料含胶量为37.4%,在射击测试中,未被击穿。凹陷深度仅有18mm,小于标准的25mm,说明该环氧胶粘剂以及纤维与树脂复合工艺能够研制出综合性能优异的防弹复合材料。

抗87式5.8 mm普通弹防弹插板的研究与制备

为了开发抗87式5.8 mm普通弹陶瓷复合防弹插板,采用有限元数值模拟研究了弹体侵彻过程及结构设计,探索了防弹插板制备过程中超高分子质量聚乙烯(UHMWPE)背板的压制工艺以及异形多曲面整板陶瓷插板的真空热压复合工艺。针对UHMWPE背板开展了不同压制压力和温度对其防弹性能影响规律的研究,并探究了真空热压参数对插板的防弹性能影响,确定了最佳的工艺参数设置,成功制备出满足国内军方要求的抗87式5.8 mm普通弹轻质插板产品,该产品能够实现有效防弹。

防弹防刺高性能纤维及复合材料研究进展

从纤维种类、织物结构等角度总结了防弹防刺纤维复合材料的研究概况,重点分析芳纶纤维、超高分子量聚乙烯纤维在防弹防刺复合材料领域的应用及其防弹防刺机理;简要介绍了聚对苯撑苯并双噁唑纤维、聚(2,5-二羟基-1,4-苯撑吡啶并二咪唑)纤维和“蛛丝”纤维等新型高性能纤维的特点及应用情况。总结了国内外防弹防刺服测试标准,并探讨防弹防刺纤维复合材料的发展趋势,以期为更高性能防弹防刺复合材料的设计与制备提供参考。

碳化硼陶瓷/UHMWPE纤维复合靶板防弹性能仿真与实弹验证

目的:为实现防弹靶板的轻量化和高防护性,对碳化硼陶瓷/超高分子量聚乙烯(ultra-high molecular weight polyethylene,UHMWPE)纤维复合靶板的防弹性能进行仿真优化与实弹验证。方法:首先,基于ANSYS/LS-DYNA建立碳化硼陶瓷/UHMWPE纤维复合靶板的有限元模型。其次,对子弹侵彻不同厚度搭配的防弹靶板过程进行仿真,分析防弹靶板对100 m处56式7.62 mm普通枪弹的防护效果。最后,基于仿真结果,以靶板的防护性和质量作为主要指标,对靶板进行优化设计,并通过实弹射击验证设计靶板的防弹性能。结果:仿真结果表明,不同厚度搭配的防弹靶板都可以实现对100 m处56式7.62 mm普通枪弹的有效防护;实弹验证结果表明,仿真结果准确,设计的防弹靶板具有较好的防护性。结论:对碳化硼陶瓷和UHMWPE纤维设置合理的配比可以满足防弹靶板的高防护性和轻量化需求,该研究可为轻质、高防护性防弹靶板的研发提供参考。

高性能防弹防刺材料研究进展

高性能纤维具有强度高、模量高、耐腐蚀和抗冲击的特性,其织物不但具备较好的弹道吸能作用,且轻质柔软,穿着舒适性好,被广泛应用于软质防弹防刺服。介绍防弹防刺材料的防护机理、相关标准、纤维及织物结构,展望未来柔性防弹防刺服研究方向和发展前景,为制备具有高防护、轻量化、灵活性的软质防弹防刺服提供参考。