弹丸斜侵彻混凝土靶板过载分析

为了研究弹丸在倾斜侵彻过程中的特性分析,运用国际通用有限元非线性动力学分析软件LS-DYNA3D,对弹体在不同入射角倾斜侵彻半无限厚混凝土靶时的全过程进行了对比分析.可得出:随着入射角的增加,弹丸产生跳弹,侵彻安定性差,弹体达不到侵彻效果、起不到毁伤目标作用,验证了模型分析的正确性.     

弹丸不同倾角侵彻混凝土影响分析

为了考察弹丸在不同入射角侵彻过程的特性,利用有限元分析软件对弹丸过载环境进行数值模拟。通过分析得到弹丸侵彻过程中的弹体位移、过载加速度、应力曲线,揭示了弹体侵彻靶板的加载特性。结果表明:弹丸入射角越小,侵彻效果好,达到毁伤目标物目的;倾角越小弹头部受到损伤越大。     

超高速弹丸连续侵彻靶板仿真研究

试验验证超高速弹丸连续侵彻靶板时的侵彻效果代价过大,数值模拟预测提供了新的解决途径.建立了超高速弹丸与连续靶板模型,利用ABAQUS软件,结合Mie-Grüneisen状态方程、Johnson-Cook本构方程和Johnson-Cook断裂准则,对钨合金弹丸2km/s初速下连续侵彻钢质靶板进行仿真研究.超高速弹丸可连续侵彻6层厚度为30mm的靶板,相邻靶板受到了弹丸与飞溅单元的共同冲击,最后2块靶板主要受到飞溅单元的冲击.超高速弹丸每穿透一层靶板,头部及弹体表层发生着侵蚀变化、能量损失与速度变化.充塞穿甲是超高速动能弹的典型穿甲形式,穿甲威力大.数值模拟有助于认识超高速弹丸连续侵彻靶板的过程.     

枪榴弹侵彻木靶板时前冲过载特性仿真研究

为给枪榴弹机械触发引信性能优化设计提供参考,利用LS-DYNA软件仿真截锥形弹头不同端面直径的枪榴弹以不同着角侵彻不同厚度木质薄靶板过程,得到了弹丸头部在贯穿靶板过程中弹丸前冲过载系数和弹丸速度。结果表明:着角、弹头端面直径、靶板厚度不同时,弹丸侵彻过程中前冲过载系数变化和速度变化不同;弹丸最大前冲过载系数出现在弹丸垂直碰击靶板的初始时刻;弹丸速度在侵彻初始阶段衰减最快。在靶场射击试验考核引信触发作用灵敏度和钝感度时,应考虑弹丸着角、立靶姿态、靶板厚度和弹头端面直径等因素的影响。     

目标运动对金属射流侵彻效果的影响分析

以靶板的运动对侵彻效果的影响为重点,利用ANSYS/LS-DYNA有限元分析软件进行仿真计算,着重分析了同一射流对靶板不同运动速度下的侵彻情况。     

多层靶板结构对穿甲影响的模拟仿真研究

为探索穿甲爆破弹战斗部结构对装甲靶板的破坏机理及侵彻效果的影响因素,基于ANSYS/LS-DYNA有限元分析软件,以靶板的层数参数为仿真变量,建立半穿甲弹及靶板模型,进行数值模拟,再现了侵彻过程。通过仿真计算,得到了在靶板总厚度相同条件下,靶板层数越多,抗侵彻能力越差这一结论,为半穿甲弹结构的设计及战术技术指标要求的确定提供了依据。     

基于DYNA的柔性钨芯弹丸侵彻钢板仿真分析

基于DYNA对不同初速度下的柔性钨芯弹丸侵彻钢板过程进行仿真实验,通过对钢板侵彻效果分析,得出弹丸侵彻过程应力变化云图以及弹丸侵彻过程速度变化和弹丸侵彻前后能量变化,为柔性弹丸实际应用提供理论依据。建立的仿真方法可用于指导柔性弹的优化设计、损伤效果评估以及斜侵彻钢靶相关问题的研究。     

穿爆弹对靶板侵彻能力仿真

为研究在一定着角、着速下穿爆弹对靶板的侵彻能力情况,运用ANSYS/LS-DYNA有限元软件进行建模,对穿爆弹侵彻过程进行数值模拟,再现了侵彻过程,对比仿真结果,得出一定着角、着速下穿爆弹穿透靶板的极限厚度为20mm,为穿爆弹结构的设计提供了依据。     

基于ANSY/SLS-DYNA头部形状对钻地斜侵彻土壤影响的数值分析

运用ANSYS/LS-DYNA软件,分别对头部形状为30°锥角,60°锥角和抛物线形的钻地弹斜侵彻土壤的过程进行数值模拟,得到了运动轨迹图,弹丸侵彻加速度过载曲线,以及弹丸侵彻深度曲线;分析了过载曲线的特征,通过比较,总结出了钻地弹的头部形状对其斜侵彻土壤时运动规律和运动特性的影响,为钻地弹设计提供了参考依据。     

弹丸侵彻混凝土靶面的数值模拟与分析

对延时引信弹丸侵彻混凝土靶面进行数值模拟与分析,利用分析软件ANSYS中的LS-DYDA模块,采用仿真与数值分析的方法,分析出弹丸侵彻混凝土靶面的速度及加速度变化曲线,并通过对数据的分析与延伸计算,为检靶技术研究提供理论依据。     

RETRACTED ARTICLE: Penetrator strength effect in long-rod critical ricochet angle

3D numerical simulations were performed in order to further investigate the role of penetrator strength in the interaction of long-rods and oblique targets. Three distinctive regimes resulting from oblique impact depending on the obliquity, namely simple ricochet, critical ricochet and target perforation, were investigated in detail. Critical ricochet angles were calculated with a full 3D explicit finite element method for various impact velocities and strength of target plates and projectiles. Numerical predictions were compared with existing two-dimensional analytical models and test results. It was predicted that critical ricochet angle increases with decreasing impact velocity and that higher ricochet angles were expected if higher strength target materials are employed. But there are differences between analytical models and 3D numerical simulation results or test results. The causes for these discrepancies are established by numerical simulations which explore the validity of the penetrator strength parameter in the analytical model as a physical entity. As a matter of fact, in this paper we first investigate the role of penetrator dynamic strength using two-dimensional simulation which resulted in different penetrator strengths out of different impact velocities. Next, by applying these amounts for penetrator strength in Rosenberg analytical model the critical ricochet angle is calculated. Finally, a comparison between the present analytical method with the 3D simulation and test results shows that the new analytical approach leads to modified results with respect to Rosenberg ones. This paper was recommended for publication in revised form by Associate Editor Jeonghoon Yoo Kamran Daneshjou, is University Professor at Iran University of Science and Technology. He studied his MSC and PhD at aeronautical Engineering de-partment of Imperial college of Science and Technology in London. His own research is at the interface of solid mechanic, finite element and electromagnetic lunchers to address the sustainable development of aerospace and solid mechanic projects. His publications include 7 books and over 100 scientific papers. This article has been retracted due to copyright issues that cannot be resolved.     

平头弹撞击角度对2A12-T4铝合金板失效特性影响的数值模拟

利用有限元软件ABAQUS建立模拟模型,开展38CrSi钢弹体撞击2A12-T4铝合金板数值模拟研究,分析撞击过程中弹体撞击角度对弹道姿态及靶体失效特性的影响。基于数值仿真和实验结果,分析靶体的失效特性,确立不同撞击条件下靶体主要失效模式的转变规律,以及由此对靶体抗撞击性能的影响。研究结果表明：弹体的弹道极限速度随其撞击角度的增大先减小后增大,弹道极限速度在撞击角度约为15°时达到最小值;弹体撞击角度对靶体失效模式存在很大影响,随着弹体撞击角度的增大,靶体主要失效模式由剪切破坏逐渐过渡到撕裂破坏,靶体的撕裂程度不断加剧;弹体初始撞击角度和速度对其在撞击过程中的弹道姿态存在影响,在弹道极限速度附近表现尤为显著。     

The ricochet of spheres and cylinders from the surface of water

A theory of ricochet is proposed which permits the effect of projectile spin to be accounted for. This effect is not explained by previous theories. The critical angles for ricochet for a sphere and for a spinning cylinder are calculated, and the theory of the spinning cylinder is applied to the Barnes Wallis “bouncing bomb” developed during World War II.     

The effect of spherical projectile speed in ricochet off water and sand

Experimental results are reported for the ricochet of steel and duralumin spheres ( and 1 in. dia.), from shallow depths of water and dry sand. The critical angle for ricochet off water is shown to increase with speed to approach the theoretical limit of . For ricochet off sand the critical angle decreases with speed but a cut-off angle exists, , for which no ricochet occurs at any speed.     

6061-T651铝合金动态力学性能及J-C本构模型的修正

为合理描述6061-T651铝合金的应力流动行为,利用万能材料试验机和霍普金森压杆,分别进行准静态、高温和高应变率下的材料力学性能测试,获得材料在不同条件下的应力应变曲线。基于试验结果,修正Johnson-Cook本构模型得到MJC(Modified Johnson-Cook)模型,并标定MJC模型各项参数。为校验MJC模型及参数的有效性,利用一级气炮发射直径为5.95 mm的圆柱弹体冲击刚性靶的Taylor杆试验以及直径为12.68 mm的刚性弹撞击厚度为2 mm靶板的试验。最后,采用ABAQUS/Explicit有限元软件建立Taylor杆和弹靶冲击试验的三维模型,基于MJC本构模型进行Taylor杆冲击、以及结合MMC(Modified Mohr-Coulomb)断裂准则进行弹靶冲击的数值模拟计算。研究结果表明,修正的MJC本构模型能够有效地描述6061-T651铝合金材料在大应变、高应变率和高温下材料的应力流动行为和变形行为。     

Kevlar-129纤维复合材料的弹道侵彻数值仿真

基于 AUTODYN有限元软件,研究了Kevlar-129纤维增强复合材料的抗侵彻性能。通过质量为10 g的 FSP破片对厚度为8、10、12、14、16以及18 mm 的六组 Kevlar 纤维靶板进行撞击模拟,获得了 FSP破片贯穿6组靶板的弹道极限,并分析了靶板的弹道极限、比吸收能随板厚的变化关系。结果表明,在板厚8-18 mm范围内,Kevlar纤维靶板的弹道极限随板厚的增加呈线性增长；在此范围内,靶板的比吸收能也呈近似线性增长,但在板厚为10-16 mm时,增长稍缓。对比还发现,比吸收能随板厚的变化规律与靶板面密度的变化规律几乎相同,二者都可用于描述Kevlar-129纤维复合材料靶板在 FSP 破片碰撞下比吸收能的变化。     

The ricochet of dumb-bell shaped projectiles

Retardations and rotations were measured for five double-ended or dumb-bell shaped (d.s.) projectiles having spheres separated by a light weight rod at specific distances. The projectiles were fired into sand at approximately 100 m/sec and at an impact angle of 10°. Experimental data indicate that for identical sizes of sphere, initial speed, impact angle and projectile mass, the forces of ricochet are independent of the interspherical distance and seem to depend only on the geometry of the leading face.Tests were also carried out with two spherical and five d.s. projectiles at various entry speeds with 5°, 10° and 15° impact angles and it was found that the crater volume in sand is proportional to the initial momentum of the projectile.     

水下可移动多弹气动发射系统设计与仿真分析

针对水下可移动多弹气动发射的研究需求,对水下可移动多弹气动发射系统进行了整体设计,重点研究了弹丸的气动发射技术,建立了水下可移动多弹气动发射结构模型。通过对发射单元的有限元分析,发现发射筒与分割气室上下接触面的应变和变形量最大,但最大应变和变形量数值较小,3个发射筒往中心微偏,对发射过程没有影响。最后进行了试验研究,通过分析图片中弹丸的移动距离,绘制了水下弹丸发射的位移-时间曲线和速度-时间曲线,验证了多弹发射系统设计的可行性及可靠性,对水下发射过程中的空化现象、多弹干扰技术、水下弹道控制以及流场显示等方面的研究有重要的意义。