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The features of blast and impact that can damage a delicate target supported by a structure include both the peak pressure and the impulse delivered to the structure. This study examines how layers of elastic and visco-elastic materials may be assembled to mitigate these features. The impedance mismatch between two elastic layers is known to reduce the pressure, but dissipation is required to mitigate the transmitted impulse in light-weight armor. A novel design concept called impact or blast tuning is introduced in which a multi-layered armor is used to tune the stress waves resulting from an impact or blast to specific frequencies that match the damping frequencies of visco-elastic layers. The material and geometrical parameters controlling the viscous dissipation of the energy within the armor are identified for a simplified one-dimensional system, to provide insight into how the optimal design of multi-use armor might be based on this concept. 相似文献
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抵御小口径火炮弹道侵彻装甲防护模拟实验研究 总被引:2,自引:0,他引:2
为研究舰艇结构在小口径火炮弹道冲击下的响应以及各种舰用装甲结构抵御小口径火炮弹道冲击的有效性,以典型的小口径火炮战斗部为模拟对象,根据弹道冲击的相似理论,分别设计了模拟实验的弹体和6种靶板结构,并进行了弹道冲击实验研究。模拟实验结果表明,普通舰艇结构不能抵御小口径火炮弹道侵彻,必须设置专门的防护装甲;采用陶瓷/钢/纤维增强复合材料组合装甲结构抵御小口径火炮时,装甲防护结构比均质钢装甲减轻约60%;陶瓷材料能改变背板的破坏形式和破坏程度,大大增加背板的吸能量,此外,陶瓷对弹体的侵蚀、钝化及碎裂能大大降低弹体的侵彻能力。 相似文献
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An experimental investigation of the ballistic performance of composite armor with geometric modifications was carried out. The armor was simulated using polymeric materials. Four different geometric modifications were incorporated into the front plate of the armor, and two different adhesives were considered in this study. High-speed photography was employed to observe the real-time evolution of impact damage and to obtain the projectile penetration history. The nature and extent of damage for each modification and adhesive was estimated by postmortem inspection of the impacted armor and was compared to that obtained in unmodified armor of equal weight. The results of the study indicate that the geometric modifications after the nature and extent of damage significantly compared to conventional composite armor. The strong adhesive causes tearing of the back plate, whereas the compliant adhesive results in extensive delamination without any back plate damage. The modifications assist in spreading the damage laterally away from the impact site, thus distributing the load onto a larger area of the back plate. Calculations using a one-dimensional theoretical model also conclude that geometrical modifications improve the ballistic performance of the armor. 相似文献
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The high velocity normal impact of a three-dimensional rigid conical impactor penetrating into a two-layered ductile armor with an air gap is studied using a simplified model for an impactor–armor interaction. The goal of the study is to investigate analytically the dependence of the ballistic resistance of the armor on the order of the plates in the armor and on the width of an air gap between the plates. It is found that the ratio between the values of a single parameter depending on the material properties of the plates determines this dependence in both cases. This parameter characterizes the properties of the material of the plate; for the most widely used models of impactor–armor interaction, it is the ratio of the distortion pressure to the density of the plate. 相似文献
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基于均质钢板、聚脲涂层材料、SiC陶瓷材料设计了4种聚脲涂覆复合装甲结构,采用装药驱动预制破片试验方法开展了近炸下复合装甲结构毁伤特性实验研究,提出了各组分的毁伤破坏模式,对比分析了4种防护装甲结构的防护性能,探讨了复合装甲结构的防护机理。结果表明:作用于目标结构的破片动能远大于冲击波能,聚脲涂覆复合装甲结构的防护效能明显优于多层均质钢装甲,增加陶瓷厚度较增加背板、前面板厚度对提高整体防护效能更有效,破片撞击将引起陶瓷块大面积损伤,严重影响了其对后续着靶破片的防护性能。 相似文献
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利用Autodyn软件开展数值模拟工作,对陶瓷/金属复合装甲的防护性能与弹靶尺寸的关系进行研究。首先,建立二维轴对称SPH-Lagrange模型,并利用实验数据验证模型有效性;在此基础上对不同几何参数的弹靶撞击进行数值模拟,分析靶板厚度、靶板平面尺寸、子弹长度等对氧化铝陶瓷/铝合金复合装甲弹道极限速度的影响规律。然后,通过量纲分析,提出装甲弹道极限速度与弹靶几何参数的量纲一关系式,并在数值模拟结果的基础上建立一个装甲弹道极限速度的经验公式。 相似文献
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为考察装甲钢板和陶瓷板的抗侵彻特性,在钢纤维混凝土靶中分别加入两种不同厚度的装甲钢板和陶瓷板振动成型。在57mm轻气炮上进行了小尺寸射弹侵彻钢纤维砼复合靶试验,测量了不同速度的射弹在不同靶中的侵彻深度。研究表明,当装甲钢板的厚度在5mm范围内,射弹速度超过400m/s时,装甲钢板的厚度对侵彻深度的影响不明显。对含陶瓷板的钢纤维砼,当射弹超过一定速度时,射弹弯曲断裂。通过分析给出了射弹残余弹长与射弹的密度、射弹的动态屈服强度和垂直撞击陶瓷板的速度的函数关系,理论结果与实验数据基本一致。 相似文献
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The objective of this study was to assess the amount of energy transferred to the backing material of oil-based clay (i.e. kinetic dissipation) in ballistic tests of soft body armor panels. To determine the relationship between penetration depth (or dent volume) and impact velocity (or energy), weight dropping test with a series of steel spheres was carried out at low impact velocities, and direct shooting with a 5.56 mm NATO fragment simulating projectile (FSP) was carried out at high impact velocities. At high and low impact velocities, the volume of the dent made in the oil-based clay was proportional to the velocity of the impactor. The change in dent volume per the change in impact velocity was found to be proportional to the 1.5th power of the mass of the impactor, while the energy absorption per unit dent volume increased linearly with the impact velocity. The relationship between trauma depth (or dent volume) and kinetic dissipation of a soft body armor panel subjected to a 9 mm bullet at 436 m/s is presented, where the trauma diameter approached that of a 1.043 kg steel ball. 相似文献
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数字图像相关(digital image correlation, DIC)技术作为一种非接触、非干涉的全场无损光学量测技术,可获取材料表面的动态变形信息和破坏过程。为了评估装甲钢的抗弹性能并探索高速三维数字图像相关(3D-DIC)技术在钢板贯穿试验测试中的应用,基于氢氧爆轰驱动弹道枪开展了7发15 mm口径可变形弹体以不同速度(255~568 m/s)冲击不同厚度(5、8和10 mm)高强高硬装甲钢板的试验,并结合帧率为144 000 s?1的高速3D-DIC测试技术获取了靶板的离面位移和应变时程。随后,基于前期标定并验证的装甲钢本构模型参数,对上述试验进行了数值模拟。通过对比弹体残余速度和长度验证了有限元分析方法的可靠性。进一步通过对比试验与数值模拟得到的靶背离面位移时程曲线和不同时刻靶背的应变云图,验证了高速3D-DIC测试结果的准确性。最后,对比分析了靶板最大离面位移与弹体冲击速度和装甲钢板厚度的关系。高速3D-DIC测试技术的应用可为相关试验测试提供参考,靶板最大离面位移分析结果可为屏障类防护结构的分析验证和优化设计提供试验依据。 相似文献
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A new analytical model was established to describe the complex behavior of ceramic/metal armor under impact of deformable projectile by assuming some hypotheses. Three aspects were taken into account: the mushrooming deformation of the projectile, the fragment of ceramic tile and the formation and change of ceramic conoid and the deformation of the metal backup plate. Solving the set of equations, all the variables were obtained for the different impact velocities: the extent and particle velocity in rigid zone; the extent, cross-section area and particle velocity in plastic zone; the velocity and depth of penetration of projectile to the target; the reduction in volume and compressive strength of the fractured ceramic conoid; the displacement and movement velocity of the effective zone of backup plate. Agreement observed among analytical result, numerical simulation and experimental result confirms the validity of the model, suggesting the model developed can be a useful tool for ceramic/metal armor design. 相似文献
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装甲钢/超高性能混凝土(UHPC)复合防护结构在重点工程中抵抗弹体的高速侵彻作用具有广泛的应用前景。为评估该复合结构的抗侵彻性能,对两种复合靶体开展侵彻试验与数值模拟研究。首先,开展了12发30 mm口径30CrMnSiNi2A弹体372~646 m/s速度侵彻复合靶试验。随后通过一系列静动态力学性能试验标定装甲钢材料的本构模型参数,并建立三维有限元模型对上述试验开展数值模拟分析。通过对比试验和数值模拟得到的弹体侵彻深度、残余弹体长度和装甲钢板的失效模式,验证了装甲钢本构模型参数的可靠性。进一步基于弹道效益系数对复合靶抗侵彻性能进行了定量评估。最后,确定了不同装甲钢板厚度复合靶体的临界贯穿速度,并对弹体侵彻复合靶的弹、靶失效模式进行了讨论。 相似文献
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考虑爆炸成型弹丸(explosively-formed projectile,EFP)变截面的特性,基于流体力学Bernoulli方程和绝热剪切理论,改进了EFP垂直侵彻装甲钢板靶后破片质量模型,结合已有的试验数据和数值仿真方法检验了改进后模型的准确性。在此基础上,分析了靶板厚度和EFP着靶速度对靶板和EFP产生的靶后破片质量的影响规律。结果表明:相比于改进前的模型,改进后的模型能够更准确地解释靶板和EFP产生的靶后破片质量随靶板厚度和EFP着靶速度的变化规律;当EFP着靶速度为1 650 m/s时,随着靶板厚度从30 mm增大到70 mm,EFP变截面的特性对靶板和EFP产生靶后破片质量的影响不断增强;当靶板厚度为40 mm时,随着EFP着靶速度从1 650 m/s升高到1 860 m/s,EFP变截面的特性对靶板和EFP产生靶后破片质量的影响不断减弱。 相似文献
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采用由厚度为8 mm的前置钛合金板、面密度为60 kg/m2的高强聚乙烯纤维增强复合材料层合板抗弹芯层、厚度为8 mm的后置钢板构成的夹芯式复合装甲,模拟舰船舷侧复合夹芯舱壁结构。根据面板与芯层间是否设置20 mm的间隙,将复合装甲结构定义为无间隙式、后间隙式及前后间隙式。为研究以上3种结构在55 g圆柱体弹高速冲击下的抗弹性能及破坏机理,开展了系列弹道实验,分析了钛合金板、高强聚乙烯纤维增强复合材料层合板芯层及钢质面板的破坏模式,探讨了结构间隙对复合装甲结构抗弹性能的影响。结果表明:前置钛合金板的破坏模式为剪切冲塞,靶板背弹面产生脆性断裂并伴随碎块崩落现象;聚乙烯纤维增强复合材料板的破坏模式及钢质背板的变形范围受间隙的影响较大,前置钛合金板受间隙影响较小;相同载荷侵彻下,间隙的存在有利于提高复合装甲结构的抗弹性能。 相似文献
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《International Journal of Solids and Structures》2003,40(24):6723-6765
This paper develops an analytical model for the ballistic impact response of fibrous materials of interest in body armor applications. It focuses on an un-tensioned 2D membrane impacted transversely by a blunt-nosed projectile, a problem that has remained unsolved for a half a century. Membrane properties are assumed characteristic of the best current body armor materials (Kevlar®, Spectra®, Zylon®, S2 glass), which have very high stiffness and strength per unit weight, and low strain-to-failure. Successful comparisons will be made with extensive experimental data on such material systems as reported by Cunniff [Decoupled response of textile body armor. Proc. 18th Int. Symp. of Ballistics, San Antonio, Texas, 1999a, pp. 814–821; Vs–Vr relationships in textile system impact. Proc. 18th Int. Symp. of Ballistics, San Antonio, Texas, 1999b; Dimensional parameters for optimization of textile-based body armor systems, Proc. 18th Int. Symp. of Ballistics, San Antonio, Texas, 1999c, pp. 1303–1310]. Our mathematical formulation draws on the seminal work of Rakhmatulin and Dem’yanov [Strength Under High Transient Loads, 1961, pp. 94–152]. Under constant projectile velocity we first develop self-similar solution forms for the tensile ‘implosion’ wave and the curved cone wave that develops in its wake. Through matching boundary conditions at the cone wave front, we obtain an accurate approximate solution for the membrane response including cone wave speed and strain distribution. We then consider projectile deceleration due to membrane reactive forces, and obtain results on cone velocity, displacement and strain concentration versus time. Other results obtained are the membrane ballistic limit, or V50 velocity, and the residual velocity when penetrated above this limit. We then derive an exact functional representation of a V50 ‘master curve’ found empirically by Cunniff [ibid] to reduce data for a wide variety of fabric systems impacted by blunt cylindrical projectiles. This curve is given in terms two dimensionless parameters based only on fiber mechanical properties and the ratio of the fabric areal density to the projectile mass divided by its area of fabric contact. Our functional representation has no fitting parameters beyond one reflecting uncertainty in the effective diameter of the impact zone relative to the projectile diameter, and even then the values are consistent across several experimental systems. The extremely successful comparison of our analytical model to experimental results in the literature raises fundamental questions about many long-held views on fabric system impact behavior and parameters thought to be important. 相似文献
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