陶瓷/纤维复合装甲抗弹丸侵彻性能的试验与数值模拟研究

本工作研究了由碳化硼(B4C)/碳纤维(CF)/超高分子量聚乙烯纤维(UHMWPE)组成的复合装甲对抗7.62 mm穿甲燃烧弹的抗侵彻性能.通过实验和数值模拟,系统地研究了陶瓷复合装甲各层对弹丸的作用机理.首先将模拟与实验结果进行比较,验证了模拟方法的可靠性.在此基础上,开展了陶瓷复合装甲的陶瓷面板的材料/厚度数值模拟研究,分别采用氧化铝(Al2 O3)、碳化硅(SiC)、碳化硼(B4 C)作为陶瓷面板,研究了不同厚度陶瓷板的吸能效率,结果表明,以B4 C陶瓷作为面板,当其厚度为10 mm时所得复合装甲的防弹性能最佳.     

碳化硅-超高分子量聚乙烯纤维增强树脂基复合材料复合装甲板的抗穿甲弹侵彻性能及其损伤机制

以碳化硅陶瓷(SiC)作为面板材料,超高分子量聚乙烯纤维增强水性聚氨酯树脂基复合材料层压板(UHMWPE/WPU)作为背板材料,通过真空袋膜压工艺制备SiC-UHMWPE/WPU复合装甲板。基于弹道冲击试验研究复合装甲板的结构参数对其抗穿甲弹侵彻性能的影响,采用X射线计算机断层扫描(X-ray computed tomography,CT)技术,研究复合装甲板在53式7.62 mm穿甲弹以弹速为(808(-8)⁺⁷)m/s进行多发弹道侵彻下的损伤模式。研究结果表明：SiC-UHMWPE/WPU复合装甲板的抗多发弹道侵彻能力随着UHMWPE/WPU厚度或SiC厚度的降低而逐渐下降,10 mm厚SiC+13 mm厚UHMWPE/WPU是试验中抗53式7.62 mm穿甲弹多发弹道侵彻的最佳工程应用结构;UHMWPE/WPU面密度的减少不仅影响UHMWPE/WPU的防护效率,其还通过降低对陶瓷面板的支撑作用,间接影响陶瓷的防护效率;弹道侵彻后的复合装甲板的损伤模式包括SiC碎裂、SiC与UHMWPE/WPU的界面破坏及UHMWPE/WPU的绝热剪切破坏、拉伸变形和分层破坏...     

多层异质复合结构的动力学响应及抗侵彻性能

为研究多层异质复合结构动力学响应及抗侵彻性能,利用霍普金森试验装置,对不同材料排布顺序及含泡沫铝夹芯的多层复合结构进行冲击加载,通过贴在入射杆和透射杆上的应变片测得入射波、反射波、透射波波形,验证数值仿真模型正确性;结合数值模拟,研究不同结构对试件内部应力波传播特性和应力场分布影响规律;依据复合结构动力学响应特征,设计复合靶板并进行抗侵彻试验,分析靶板塑性变形特征及抗侵彻耗能机制;通过数值模拟分析泡沫铝夹芯厚度对防护性能影响。结果表明,装甲钢后置复合结构及含泡沫夹芯结构有助于减缓应力集中,减小陶瓷损伤面积;泡沫铝夹芯过厚难以为靶板变形提供支撑,降低抗侵彻阻力;五种夹芯厚度h=2 mm、h=5 mm、h=10 mm、h=20 mm、h=30 mm中,h=10 mm对应多层异质复合靶防护性能最优。      

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。     

陶瓷/纤维/阻尼复合靶板抗冲击性能及优化

随着弹体的侵彻能力逐渐增强，复合防弹装甲成为不可或缺的装备之一。基于ANSYS建立了陶瓷/纤维/阻尼复合防弹靶板的冲击有限元模型，揭示了材料参数和几何参数对复合防弹靶板的影响规律，利用多目标遗传算法优化了碳化硅陶瓷/碳纤维/超高分子量聚乙烯纤维/背层阻尼复合防弹靶板结构，并通过实验验证了优化设计结果的可信性。结果表明：同面密度条件下，涂刷一定厚度背层阻尼对靶板防弹性能的提升较为显著；采用遗传算法优化后的复合防弹靶板结构为：6.9mm碳化硅陶瓷/4.8mm碳纤维层合板/6.0mm超高分子量聚乙烯(UHMWPE)纤维层合板/1.1mm阻尼，面密度为36.236kg/m²。相同防弹性能条件下，与陶瓷/装甲钢结构靶板相比，优化后的靶板面密度降低超过49%。     

某陶瓷/钢复合装甲抗大质量破片侵彻能力研究

陶瓷/金属复合结构装甲具有质量轻、抗弹性能优异的特点,广泛应用于各类轻质装甲中。为得到某陶瓷/钢复合装甲抗大质量破片的侵彻能力,在与已有试验结果对比验证的基础上,运用ANSYS/LS-DYNA软件对大质量破片侵彻该陶瓷/钢复合装甲过程进行数值模拟,分析破片初速、装甲倾角对破片极限穿透速度和后效威力的影响,以及侵彻过程中破片能量变化,获得了该复合装甲的抗侵彻规律,并利用工程算法计算得到装甲防护系数。结果表明：随着装甲倾角的增加,破片极限穿透速度先减小后增大,剩余速度和剩余质量先增大后减小,装甲存在一个“最易侵彻角”;随着破片初速的增加,破片剩余速度呈线性递增,剩余质量呈线性递减;通过工程算法得到该装甲面密度为普通装甲钢的74%,对破片的防护系数达到1.5。     

蜂窝点阵-陶瓷复合装甲在联合载荷下的动态力学行为EI北大核心CSCD

为了探究具备抗多发弹打击的蜂窝点阵-陶瓷复合装甲在冲击波与破片联合载荷下的防护性能,改善当前防护装甲基于破片或爆炸冲击波单一载荷开展结构设计的不足。通过泡沫铝-弹丸复合弹模拟联合载荷,采用有限元模拟,研究蜂窝点阵-陶瓷复合装甲在联合载荷作用下的结构动态响应与毁伤机理,明确速度差和预变形两种协同作用机制;进一步研究联合载荷中爆炸冲击波与破片抵达先后顺序与抵达时间差对复合装甲防护性能的影响。最终,进行参数化研究,讨论蜂窝点阵-陶瓷复合装甲中,不同子结构关键几何参数对防护性能的影响规律,评估不同子结构的防护贡献,为最优防护性能设计提供指导。     

新型复式连通SiC/390Al复合材料的制备和性能

以空心多孔SiC泡沫陶瓷为增强体,用挤压铸造法制备了新型复式连通双连续相SiC/390Al复合材料,研究了泡沫陶瓷骨架筋的结构对复合材料的影响,以及复合材料中的界面对力学性能的影响.结果表明,SiC空心多孔泡沫陶瓷与390Al复合后形成了复式连通双连续相复合材料,具有独特的互穿式界面结构,材料界面的结合优异.随着复合材料界面结合的加强和泡沫增强体的复合韧化,复合材料的屈服强度、压缩强度和弯曲强度明显提高,韧性显著增强.     

仿生鳞片式拼接柔性防护结构防弹性能研究

目的 根据仿生学原理,借鉴鳞甲类生物柔性拼接模式,设计出由碳化硼陶瓷和超高分子量聚乙烯(UHMWPE,PE)背板复合而成的仿生鳞片式拼接柔性防护结构,以提高防护装备的灵活性和抗多发弹性能。方法 首先通过高温热压成形工艺制备出复合鳞片,然后采用95式5.8 mm钢芯弹进行侵彻试验,最后结合有限元仿真对侵彻过程中的弹击损伤机制和能量耗散形式进行分析。结果 弹丸侵彻导致复合鳞片的陶瓷层发生了严重的碎裂现象,PE背板发生了类圆状凹陷变形,但未被穿透;单次弹击损伤范围被限制在弹击鳞片及其相邻鳞片附近,未形成大面积损伤,表现出优异的抗多发弹性能;弹丸的能量通过弹击鳞片扩散到与其相邻的鳞片上,降低了弹丸对弹击鳞片的损伤,提高了柔性结构的极限抗单发弹性能。结论 仿生鳞片式拼接柔性结构能够有效抵御95式5.8 mm钢芯弹的侵彻,具备柔性的同时还具有优异的抗多发弹性能,可应用于新一代单兵及武器装备的小口径枪弹防护装甲。     

陶瓷复合装甲粘结层效应和抗多发打击性能的数值模拟研究

粘结层性能对陶瓷复合装甲抗多发打击性能有重要影响。建立了研究粘结层和多发打击的数值模拟方法,解决了传统方法不能模拟“脱粘”和多发打击的问题。基于文献弹道试验,研究了环氧树脂和聚氨酯两种粘结层材料及其厚度对陶瓷/铝合金复合装甲抗7.62mm 穿甲弹单发和两发打击性能的影响。结果表明:单发打击的数值模拟可不建粘结层,而多发打击应采用建粘结层的方法;抗单发打击时,粘结层越薄,极限速度越大;抗多发打击时,陶瓷复合装甲应采用聚氨酯粘结层,且其抗两发打击的较优厚度约为0.40mm。     

Aluminum foam integral armor: a new dimension in armor design

Closed-cell aluminum foam offers a unique combination of properties such as low density, high stiffness, strength and energy absorption that can be tailored through design of the microstructure. During ballistic impact, the foam exhibits significant non-linear deformation and stress wave attenuation. Composite structural armor panels containing closed-cell aluminum foam are impacted with 20-mm fragment-simulating projectiles (FSP). One-dimensional plane strain finite element analysis (FEA) of stress wave propagation is performed to understand the dynamic response and deformation mechanisms. The FEA results correlate well with the experimental observation that aluminum foam can delay and attenuate stress waves. It is identified that the aluminum foam transmits an insignificant amount of stress pulse before complete densification. The ballistic performance of aluminum foam-based composite integral armor (CIA) is compared with the baseline integral armor of equivalent areal-density by impacting panels with 20-mm FSP. A comparative damage study reveals that the aluminum foam armor has finer ceramic fracture and less volumetric delamination of the composite backing plate as compared to the baseline. The aluminum foam armors also showed less dynamic deflection of the backing plate than the baseline. These attributes of the aluminum foam in integral armor system add a new dimension in the design of lightweight armor for the future armored vehicles.     

陶瓷-金属复合材料在防弹领域的应用研究

陶瓷-金属复合材料具备高硬度、高强度、高韧性以及低密度的优点,已被广泛应用于防弹领域.介绍了几种陶瓷-金属复合装甲形式及其相应特点,重点论述了陶瓷-金属功能梯度装甲的研究进展,并对其前景和当前的工作重点进行了讨论.     

止裂层对陶瓷复合防弹插板冲击损伤行为研究

目的 研究冲击载荷下迎弹面覆盖止裂层的复合防弹插板陶瓷面板碎裂机理和抗侵彻性能。方法 对所设计的复合防弹插板进行空气炮打靶试验,构建冲击仿真有限元计算模型。结合试验和数值模拟,研究覆盖环氧树脂、凯夫拉平纹织物止裂层及无止裂层复合防弹插板的抗侵彻性能,分析不同冲击速度下复合防弹插板陶瓷损伤失效过程。采用内聚力单元对止裂层和陶瓷之间的黏结区域进行建模,分析黏结程度对陶瓷损伤和失效的影响。结果 止裂层表面约束的陶瓷在冲击过程中产生的径向裂纹随着撞击点附近的环向拉应力波的传播而延伸。止裂层黏结作用增强时,陶瓷的冲击缺口面积增大,但质量损失基本不变;迎弹面止裂层未对侵彻过程中子弹动能和复合防弹插板背凸情况产生显著影响。结论 止裂层在一定程度上能减少陶瓷质量损失,但也会造成更多的损伤,这种现象在高速情况下较为明显,且凯夫拉平纹织物止裂层所造成的损伤更多。相关研究工作可为陶瓷复合防弹板的设计提供参考。     

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。      

The effect of hybridization on the ballistic impact behavior of hybrid composite armors

In the present study, effect of hybridization on the hybrid composite armors under ballistic impact is investigated using hydrocode simulations. The hybrid composite armor is constructed using various combinations and stacking sequences of fiber reinforced composites having woven form of fibers specifically high specific-modulus/high specific-strength Kevlar fiber (KF), tough, high strain-to-failure fiber Glass fiber (GF) and high strength/high stiffness Carbon fiber (CF). Different combinations of composite armors studied are KF layer in GF laminate, GF layer in KF laminate, KF layer in CF laminate and CF layer in KF laminate at various positions of hybridized layers for a fixed thickness of the target. In this article the results obtained from the finite element model are validated for the case of KF layer in a GF laminate with experimental predictions reported in the literature in terms of energy absorption and residual velocity and good agreement is observed. Further, the effect of stacking sequence, projectile geometry and target thickness on the ballistic limit velocity, energy absorbed by the target and the residual velocity are presented for different combinations of hybrid composite armors. The simulations show that, at a fixed thickness of the hybrid composite armor, stacking sequence of hybridized layer shows significant effect on the ballistic performance. The results also indicate energy absorption and ballistic limit velocity are sensitive to projectile geometry. Specifically, it is found that arranging the KF layer at the rear side, GF layer in the exterior and CF layer on the front side offers good ballistic impact resistance. The hybrid composite armor consisting of a CF layer in KF laminate acquires maximum impact resistance and is the best choice for the design compared to that of other combinations studied.     

Ballistic resistance of high hardness armor steels against 7.62 mm armor piercing ammunition

Although advanced lightweight composite based armors are available, high hardness steels in military vehicles are often used to provide ballistic protection at a relatively low cost and is an interesting material due to its widespread usage in vehicle structure. In this study, ballistic limit of 500 HB armor steel was determined against 7.62 mm 54R B32 API hardened steel core ammunition. Lagrange and smoothed particle hydrodynamics (SPH) simulations were carried out using 3D model of bullet and high hardness armor target. Perforation tests on 9 and 20 mm thickness armor were performed to validate simulation methodology. Also material tests were performed for armor steel and ammunition hardened steel core to develop Johnson–Cook constitutive relations for both strength and failure models. Finally, results from 3D numerical simulations with detailed models of bullet and target were compared with experiments. The study indicates that the ballistic limit can be quantitatively well predicted independent of chosen simulation methodology, but qualitatively some differences are seen during perforation and fragmentation. As shown in results, good agreement between Ls-Dyna simulations and experimental data was achieved by Lagrange formulation with the full bullet model.     

新型集成装甲对EFP侵彻性能的影响

根据平板装药和陶瓷复合装甲与爆炸成型弹丸（EFP）相互作用的原理，提出了新型集成装甲与EFP作用的计算模型；据此模型进行了EFP残余速度计算，证明了在相同面密度的新型集成装甲和陶瓷复合装甲防护下，EFP的残余速度有明显差异；根据该计算模型可进行集成装甲的优化和EFP的反装甲目标设计。     

Strength estimation of ceramic–metal joints with various interlayer thickness

ABSTRACT Residual stresses generated by the mismatch of thermal expansion coefficients of ceramics and metals affect the strength of ceramic–metal joints. An interlayer metal can be inserted between the ceramic and metal in order to relax this stress. An analysis was carried out of the residual stresses produced during joint‐cooling and in 4‐point bending tests. The effects of interlayer thickness on ceramic–metal joint strength were then studied by considering a superimposed stress distribution of the residual stress and the bending stress. Finally, joint strength was estimated from fracture mechanics and strength probability analysis by considering the residual stress distribution, defect size and position of pre‐existing defects in the ceramic parts. As a result of this study, we suggest an optimum material selection and interlayer thickness for ceramic–metal joint structures. This approach is generally suitable for the design of electrical and mechanical structures.