抵御小口径火炮弹道侵彻装甲防护模拟实验研究

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。     

长杆弹撞击装甲陶瓷界面击溃/侵彻转变速度理论模型

为预测长杆弹撞击装甲陶瓷界面击溃/侵彻转变过程,采用Hertz接触理论确定靶体内部应力,将其分别应用于陶瓷锥裂纹与翼型裂纹扩展理论。通过比较两种裂纹扩展模型计算得到的界面击溃/侵彻转变速度,提出准确预测界面击溃/侵彻转变速度的理论模型。结果表明：将两种裂纹扩展理论相结合的理论模型可以合理地解释界面击溃/侵彻转变过程,转变速度计算结果与已有实验结果吻合较好。弹体半径较小时,锥裂纹扩展控制界面击溃/侵彻转变过程;弹体半径较大时,翼型裂纹扩展控制界面击溃/侵彻转变过程。

     

反应装甲与陶瓷复合装甲集成技术研究探讨

为了得到抗弹性能较好的装甲,将反应装甲与陶瓷复合装甲集成。由长杆弹侵彻复合装甲的理论和撞击反应装甲时的动量定理,得出计算模型。据此模型进行了侵彻深度的数值计算,并证明相同面密度的集成装甲的抗弹性能明显优于陶瓷复合装甲。根据此计算模型对集成装甲进行优化设计,以得到较轻和抗弹性能较好的装甲。     

Interface defeat of ceramic armor

界面击溃效应(interface defeat)是射弹撞击陶瓷材料过程中,陶瓷表面产生的特有现象.国内外学者在近30年来对陶瓷界面击溃效应开展的大量研究工作表明界面击溃效应中射弹界面驻留(dwell)时间的增加以及界面击溃/侵彻转变速度的升高能够大量消耗弹体动能、有效提高装甲陶瓷的抗弹性能.本文主要从实验、理论和数值模拟三方面介绍国内外学者开展的工作,包括陶瓷界面击溃效应的宏观与微观力学机制及其研究方法等.针对现今对界面击溃效应研究的不足, 提出了关于未来研究方向的建议.     

ANALYTICAL MODEL OF CERAMIC/METAL ARMOR IMPACTED BY DEFORMABLE PROJECTILE

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.     

基于复合面/背板的平板装药防护性能

采用实验和数值模拟方法研究了橡胶复合板作为爆炸反应装甲面、背板时的防护性能,分析了两种反应装甲结构的防护机理,并与面密度相同的钢反应装甲进行了对比。实验结果表明:爆炸反应装甲面板或背板为橡胶复合板时的防护性能优于钢反应装甲,其中橡胶复合板作为背板时效果最优。数值模拟结果表明:橡胶复合板在爆炸驱动下外层钢板速度相比于钢反应装甲飞板提高16%,橡胶复合板的界面效应及其飞板间隙可以有效减小逃逸射流的长度。     

铝质舰体轻型复合装甲试验研究

以纤维增强复合材料（FRP）层合板前置铝板模拟铝质舰体轻型复合装甲结构,对采用不同增强纤维FRP层合板有间隙复合装甲结构进行7.62 mm制式尖头弹打靶试验。基于FRP抗弹机理的分析,着重讨论了入射角度和增强纤维种类对组合装甲结构抗弹性能的影响,对铝质舰体设置轻型复合装甲以抵御小口径武器攻击的可行性进行评估。     

Optimization of two component ceramic armor for a given impact velocity

Using Florence’s model a problem of two-component ceramic-faced lightweight armors design against ballistic impact is solved. Approximate analytical formulas are derived for areal density and thicknesses of the plates of the optimal armor as functions of parameters determining the properties of the materials of the armor components, cross-section and mass of an impactor, and of the expected impact velocity.     

不同撞击速度下穿燃弹侵彻陶瓷/铝合金复合靶板时弹芯破碎失效特性研究

为了研究12.7 mm穿燃弹以不同速度撞击陶瓷/铝合金复合靶板时弹芯的破碎及失效特性,开展了12.7 mm穿燃弹以434.5～844.6 m/s速度撞击SiC陶瓷/6061T6铝合金复合靶板的弹道试验,分析了弹靶的失效模式。弹芯在侵彻靶板后会产生不同尺寸的碎片,使用回收箱收集弹芯碎片并用不同孔径筛网对其进行筛分、称重,得到了不同撞击速度下弹芯碎片的质量分布,并对不同部位的弹芯碎片断口形貌进行了宏观和微观观测分析。研究结果表明:背板失效模式为碟形变形-剪切穿孔-花瓣形失效,试验后的弹芯碎片累积质量分布符合Rosin-Rammler幂率分布规律,且随着着靶速度的增大,小质量碎片质量增加;弹芯在冲击过程中等效直径较大碎片（大于8 mm）失效模式为拉伸脆性断裂,而等效直径小于2 mm的碎片上存在局部塑性剪切断裂。     

结构间隙对夹芯式复合装甲结构抗侵彻性能的影响

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。

     

陶瓷/金属复合装甲冲击响应的三维SPH法分析

采用自编三维SPH程序对弹体侵彻陶瓷/金属复合装甲问题进行了数值模拟.为了描述金属和陶瓷材料非线性变形及损伤特性,在程序中嵌入Johnson-Cook和Johnson-Holmquist Ⅱ本构模型及Mie-Gruneisen状态方程.SPH计算得到的典型位移随时间变化曲线与实验结果吻合较好.通过数值模拟合理再现了弹体...     

多目标优化算法在弹头侵彻明胶运动模拟中的应用

为使弹道模型更好地模拟弹头侵彻明胶的运动规律,从而有助于揭示弹头对人体组织的致伤机理,以弹头水平位移、竖直位移、侧向位移、俯仰角以及偏航角理论值的均方根误差作为目标函数组,以弹头的待定初始运动参数和弹道模型的待定力学系数作为优化变量,通过Gamultiobj多目标遗传算法获得了的优化变量的Pareto解集,并通过TOPSIS综合分析方法获得了Pareto解集的最优解。研究结果表明该方法能够快速获得可信性较强的最优解,使最优解能较好地模拟7.62 mm步枪弹侵彻明胶的运动过程。

     

动能杆斜撞击靶板后效破片描述研究

针对动能杆式弹大倾角斜撞击靶板产生的靶后破片,建立了其初始破片云数学描述模型,并在此基础上对斜撞击靶后破片特征分布进行了建模。仿真结果与工程试验结果的比较表明,该模型具有较高的可信度。     

月牙形空腔结构金属靶的抗弹性能分析

为提高金属靶的抗弹性能,设计了一种含有月牙形空腔结构的金属靶。利用ABAQUS软件对月牙形空腔结构在12.7 mm穿甲燃烧弹弹芯侵彻下的弹体偏转性能进行了数值模拟研究,讨论了月牙形状、弹着点和空间排布对弹体偏转效果的影响。结果表明:月牙形状对弹体的偏转效果有显著的影响;空腔结构在不同弹着点表现出不同的弹体偏转性能,处于空腔胞元最薄弱处附近的弹着点弹体偏转角度明显小于其他位置;空腔胞元空间排布的非对称化处理能够提升空腔结构对子弹的偏转效果。     

Impact response of a piezoelectric layered composite plate with a crack

The dynamic response of a central crack in a piezoelectric layered composite plate under normal impact is analyzed. The crack is oriented normally to the interfaces. The Laplace and Fourier transform techniques are used to formulate the problem in terms of a singular integral equation. The order of stress singularity around the tip of the terminated crack is also obtained. Numerical calculations are carried out, and the main results presented are the variations of the dynamic stress intensity factor and the dynamic energy density factor versus time as functions of the geometric parameters and the piezoelectric material properties of the layered composite plate.     

12.7 mm动能弹斜侵彻复合装甲的数值模拟研究

通过弹道枪实验对斜置角度为0°～60°的陶瓷复合装甲进行了弹道极限测试,分析了靶板斜置角度对穿燃弹的弹道极限和钢芯质量变化、破坏形态的影响。利用数值模拟的方法对上述实验结果进行验证计算,鉴于数值计算结果与实验结果较好的一致性,进一步研究了陶瓷复合靶板斜置角度对穿燃弹钢芯穿靶偏移角和等效Q235钢靶厚度的影响。结果表明,随陶瓷复合靶板斜置角度的增大：弹道极限近似指数型提高;在相同弹道极限速度下,穿燃弹对Q235钢靶板的极限穿深和对斜置陶瓷复合靶板的极限穿深的等效厚度的比也随之增大;同时,钢芯完整度逐渐降低,穿靶偏移角反向增大。

     

新型反应装甲结构对长杆弹小法线角侵彻的干扰分析和防护效能

针对防御小法线角入射的长杆弹的需要而设计出了一种新型反应装甲结构。通过分析新型反应装甲结构对长杆弹运动速度和姿态的干扰,得出在长杆弹质量守恒的情况下的动力学方程,并进行反应装甲抗长杆弹侵彻实验。结果表明,新型反应装甲能够有效的干扰小角度长杆弹的飞行姿态并造成动能损失,可提高对长杆弹的防护效果。     

Modelling of dynamic ductile fracture and application to the simulation of plate impact tests on tantalum

A model of dynamic damage by void nucleation and growth is proposed for elastic-viscoplastic materials sustaining intense loading. The model is dedicated to ductile materials for which fracture is caused by microvoiding. The material contains potential nucleation sites where microvoids are generated when the local pressure overcomes the nucleation pressure. A probability density function is adopted to describe the fluctuation of the nucleation pressure within the material. The void growth is described by using a hollow sphere model where micro-inertia effects are accounted for. The matrix weakening due to void growth is also included.The model has been first tested under uniaxial deformation. When the strain rate is assumed constant, the pressure inside the material has nearly a linear response up to a maximum. An analytical expression for the maximum pressure is proposed.Finite element simulations of plate impact tests have been carried out and compared to experiments on tantalum. From simulations based on the proposed model, an increase of the spall strength is observed with higher shock intensities. Therefore, the relationship between the velocity pullback and spall strength usually assumed in the literature (based on the acoustic approach) seems to be inadequate. Velocity profiles are simulated for different flyer thicknesses and different impact velocities with close agreement with experiments.     

Penetration of sandwich plates with hybrid-cores under oblique ballistic impact

The oblique penetration performance of lightweight hybrid-cored sandwich plates are investigated numerically. To compose the hybrid-core, ceramic prisms are inserted into pyramidal metal lattice trusses and fixed using epoxy resin. Three-dimensional finite element simulations are carried out for the hybridcored sandwich impacted at 15°, 30°, 45°, and 60° obliquity by a hemispherical projectile. The ballistic limit, the energy absorbed by the constituting elements, and the critical oblique angle are quantified. The physical mechanisms underlying the failure and the influence of fundamental system parameters are explored. The angle of obliquity is found to have significant influence on the ballistic trajectory and erosion of the projectile, thus it is important for the impact response and penetration resistance of the sandwich. For oblique angles equal to or larger than 45°, the projectile moves mainly horizontally and can not effectively penetrate across the sandwich.     

基于细观混凝土模型的刚性弹体正侵彻弹道偏转分析

为研究混凝土细观因素对刚性弹正侵彻弹道偏转的影响,基于骨料随机投放的思路建立混凝土三维细观几何模型,分析刚性弹正侵彻过程中发生弹道偏转的原因及可能影响因素,定量讨论混凝土细观因素对弹道偏转的影响。结果表明:混凝土细观数值模型可以较好地反映弹体正侵彻过程中弹道偏转等典型物理现象,且细观参数对于弹体弹道偏转有显著影响。刚性弹正侵彻细观混凝土时,存在一个弹体直径/骨料最大粒径比的特征比值。