共查询到20条相似文献,搜索用时 31 毫秒
1.
《International Journal of Solids and Structures》2007,44(10):3411-3439
The present study deals with the experimental and numerical investigations of aluminum target plates impacted by blunt, ogive and hemispherical nosed steel projectiles. The projectiles were normally impacted on the target plates of 0.5, 0.71, 1, 1.5, 2, 2.5 and 3 mm thicknesses at different velocities with the help of a pneumatic gun. Effect of projectile nose shape, impact velocity and plate thickness on the deformation of the target plates was studied. Hemispherical nosed projectile caused highest global deformation (dishing) of the target plates. Ogive nosed projectiles were found to be the most efficient penetrator for the case of plates of thicknesses 0.5, 0.71, 1.0 and 1.5 mm. For the case of plates of thicknesses 2.0, 2.5 and 3.0 mm however, blunt nosed projectiles required least energy to perforate the target plates. The ballistic limit velocity of hemispherical nosed projectiles was found to be highest as compared to the other two projectiles. Finite element analysis of the problem was carried out using ABAQUS finite element code. Results of the numerical analysis were compared with the experiments and good correlation between the two was found. 相似文献
2.
3D numerical simulations of ductile targets subjected to oblique impact by sharp nosed projectiles 总被引:1,自引:0,他引:1
Three-dimensional numerical simulations have been performed to study the behaviour of ductile targets subjected to normal and oblique impact by sharp nosed cylindrical projectiles. Twelve-mm-thick Weldox 460 E steel targets were impacted by 20 mm diameter projectiles with conical nose and 1-mm-thick 1100-H12 aluminum targets were impacted by 19 mm diameter ogive nosed projectiles. In both the cases, the targets were impacted at 0°, 15°, 30°, 45° and 60° obliquity or until the ricochet of the projectile occurred. The ballistic limit of 12 mm steel targets was found to be almost same up to 30° obliquity and thereafter it increased sharply. However, in the case of 1 mm aluminum targets a consistent increase in the ballistic limit was observed with increase in obliquity. The critical angle of projectile ricochet was found to increase with increase in impact velocity. Both the targets failed through ductile hole enlargement. Petal formation occurred in the aluminum targets and four petals were generally formed in each plate, however, the size of the upper two petals decreased and that of the lower two petals increased with increase in target obliquity. In the case of the steel targets the perforation occurred through the formation of a hole enclosed by a bulge. Both the bulge and the hole were circular in normal impact and elliptical in oblique impact. Petal formation in steel targets was observed at 60° obliquity. The ABAQUS/explicit finite element code was used to carry out numerical simulations. 相似文献
3.
M.A. Iqbal G. Gupta A. Diwakar N.K. Gupta 《European Journal of Mechanics - A/Solids》2010,29(4):683-694
Three-dimensional numerical simulations were carried out to study the ballistic resistance of ductile targets subjected to normal impact by the projectiles. 12 mm thick Weldox 460 E steel targets were impacted by 20 mm diameter conical nosed projectiles and 1 mm thick 1100-H12 aluminum targets were impacted by 19 mm diameter ogive nosed projectiles. The internal nose angle of conical projectile was varied (33.4°–180°) and found to have significant effect on the ballistic limit of 12 mm thick Weldox 460 E steel target. Similarly, the caliber radius head (CRH) of ogive nosed projectile was varied (0–2.5) and found to have significant effect on the ballistic limit of 1 mm thick 1100-H12 aluminum target. The ballistic limit of 12 mm thick Weldox 460 E steel target increased almost linearly with the decrease in the projectile nose angle. While the ballistic limit of 1 mm thick 1100-H12 aluminum target increased as the CRH increased from 0 to 0.5 and with further increase in CRH to 1.0, 1.5, 2.0 and 2.5 its values were found to drop quite significantly. ABAQUS/Explicit finite element code was used to carry out the numerical simulations. 相似文献
4.
Q235钢板对半球形头弹抗侵彻特性 总被引:3,自引:0,他引:3
利用轻气炮进行了半球形头杆弹正撞击单层板和等厚接触式三层板的实验, 得到了这两种结构靶体的初始-剩余速度曲线以及弹道极限。采用ABAQUS/EXPLICIT数值模拟软件对杆弹撞击金属板的过程进行了数值模拟研究, 通过对比数值模拟和实验结果, 验证了数值模拟材料模型和参数的有效性。研究了靶体结构对抗侵彻特性的影响, 并分析了弹体对靶体的撞击过程。研究结果表明:多层板的弹道极限高于等厚单层板。单层板主要失效模式为剪切, 而多层板的主要失效模式为整体的蝶形变形和局部的盘式隆起。对于多层板, 靶板具体的失效模式与其在靶中位置相关。 相似文献
5.
《International Journal of Solids and Structures》2006,43(3-4):569-582
In this paper, a new analytical method for projectile deformation and penetration into a semi-infinite target has been developed. This method is based on separated, successive and incremental steps. In deformation step, the target assumed rigid and the increment of projectile deformation was evaluated, whilst in penetration step, the projectile assumed rigid and the increment of penetration was evaluated. These sequential steps continued untill the projectile stopped.Furthermore, a series of ballistic tests have been carried out with ogival projectiles with striking velocity of 600–900 m/s. The projectiles and target plates material has been chosen from 4 types of steel. In this way, 210 tests for 48 combinations of projectile, target and velocity have been carried out. Numerical simulation has been also performed using the LS-DYNA code.Comparison between the depth of penetration obtained by this analytical method and those of the experimental and numerical ones shows a good agreement. 相似文献
6.
Based on the three-stage perforation model, a semi-theoretical analysis is conducted for the ballistic performances of a rigid kinetic projectile impacting on concrete plates. By introducing the projectile resistance coefficients, dimensionless formulae are proposed for depth of penetration (DOP), perforation limit thickness, ballistic limit velocity, residual velocity and perforation ratio, with the projectile nosed geometries and projectile-target interfacial friction taken into account. Based on the proposed formula for DOP and lots of penetration tests data of normal and high strength concrete targets, a new expression is obtained for target strength parameter. By comparisons between the results of the proposed formulae and existing empirical formulae and large amount of projectile penetration or perforation tests data for monolithic and segmented concrete targets, the validations of the proposed formulae are verified. It is found that the projectile-target interfacial friction can be neglected in the predictions of characteristic ballistic parameters. The dimensionless DOP for low-to-mid speed impacts of non-flat nosed projectiles increases almost linearly with the impact factor by a coefficient of 2/(πS). The anti-perforation ability of the multilayered concrete plates is dependent on both the target plate thickness and the projectile impact velocity. The variation range of the perforation ratio is 1–3.5 for concrete targets. 相似文献
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In the present paper, a four-stage perforation model that accurately predicts the residual velocity is developed by adopting an energy method. The four stages are plug formation, dishing formation, petal formation and projectile exit. In addition, some important experimental results are presented and analyzed to validate the present perforation model. In the experiments, high speed camera system is used to record the perforation process. Observations on target damage and measurements of initial velocities and residual velocities with the aid of the system are presented. Numerical simulations are carried out for projectiles against single and layered plates adopted in the experiments. The perforation process is studied and the deformation and failure modes are obtained. The predictions of numerical simulations and analytical model are found in reasonably good agreement with those of experiments, and can be used to predict the ballistic limit and residual velocity of stiffened plates perforated by rigid projectiles. 相似文献
9.
In the present paper, a four-stage perforation model that accurately predicts the residual velocity is developed by adopting
an energy method. The four stages are plug formation, dishing formation, petal formation and projectile exit. In addition,
some important experimental results are presented and analyzed to validate the present perforation model. In the experiments,
high speed camera system is used to record the perforation process. Observations on target damage and measurements of initial
velocities and residual velocities with the aid of the system are presented. Numerical simulations are carried out for projectiles
against single and layered plates adopted in the experiments. The perforation process is studied and the deformation and failure
modes are obtained. The predictions of numerical simulations and analytical model are found in reasonably good agreement with
those of experiments, and can be used to predict the ballistic limit and residual velocity of stiffened plates perforated
by rigid projectiles.
The project supported by the National Natural Science Foundation of China (90305018)
The English text was polished by Yunming Chen 相似文献
10.
Oblique perforation of thick metallic plates by rigid projectiles with various nose shapes is studied in this paper. Two perforation mechanisms, i.e., the hole enlargement for a sharp projectile nose and the plugging formation for a blunt projectile nose, are considered in the proposed analytical model. It is shown that the perforation of a thick plate is dominated by several non-dimensional numbers, i.e., the impact function, the geometry function of projectile, the non-dimensional thickness of target and the impact obliquity. Explicit formulae are obtained to predict the ballistic limit, residual velocity and directional change for the oblique perforation of thick metallic plates. The proposed model is able to predict the critical condition for the occurrence of ricochet. The proposed model is validated by comparing the predictions with other existing models and independent experimental data.The English text was polished by Keren Wang 相似文献
11.
We conducted an experimental and analytical study to understand the mechanisms and dominant parameters for ogive-nose rods
and 7.62 mm APM2 bullets that perforate 5083-H116 aluminum armor plates. The 20-mm-diameter, 95-mm-long, ogive-nose, 197 g,
hard steel rods were launched with a gas gun to striking velocities between 230–370 m/s. The 7.62-mm-diameter, 10.7 g, APM2
bullet consists of a brass jacket, lead filler, and a 5.25 g, ogive-nose, hard steel core. The brass and lead were stripped
from the APM2 bullets by the targets, so we conducted ballistic experiments with both the APM2 bullets and only the hard steel
cores. These projectiles were fired from a rifle to striking velocities between 480–950 m/s. Targets were 20, 40, and 60-mm-thick,
where the 40 and 60-mm-thick targets were made up of layered 20-mm-thick plates in contact with each other. The measured ballistic-limit
velocities for the APM2 bullets were 4, 6, and 12% smaller than that for the hard steel cores for the 20, 40, and 60-mm-thick
targets, respectively. Thus, the brass jacket and lead filler had a relatively small effect on the perforation process. In
addition, we conducted large strain, compression tests on the 5083-H116 aluminum plate material for input to perforation equations
derived from a cavity-expansion model for the ogive-nose rods and steel core projectiles. Predictions for the rod and hard
steel core projectiles are shown to be in good agreement with measured ballistic-limit and residual velocity data. These experimental
results and perforation equations display the dominant problem parameters. 相似文献
12.
为研究卵形弹丸贯穿中等厚度混凝土靶体的贯穿规律,开展直径60 mm尖卵形弹丸贯穿不同厚度混凝土靶体的侵彻实验,获得了不同撞击速度的弹丸贯穿不同厚度混凝土靶体的剩余速度规律。结合无网格SPH方法、RHT混凝土本构以及状态方程,对贯穿实验进行数值模拟,对不同工况下的弹丸过载规律以及靶体的损伤过程的分析发现:弹丸贯穿中等厚度混凝土靶体的贯穿过程分为开坑阶段、隧道稳定侵彻阶段以及靶背影响出靶阶段,在相同初始撞击速度下的靶背影响区的厚度随着靶体厚度的增加而增大。实验结果与数值模拟结果对比,表明模型能够有效模拟弹丸贯穿混凝介质问题,研究结果可为贯穿机理的研究提供参考。 相似文献
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14.
A3钢钝头弹撞击45钢板破坏模式的数值分析 总被引:4,自引:0,他引:4
不同速度范围内的A3钢钝头弹撞击45钢靶板分别表现为泰勒撞击、向日葵型花瓣帽形失效和靶板冲塞穿甲等3种不同的破坏模式,利用LS-DYNA对这种复杂的破坏机理和相应的影响因素进行了数值模拟研究。采用Johnson-Cook强度模型和累积损伤失效模型描述弹靶材料的力学性能,并考虑了塑性变形的绝热温升效应。数值模拟再现了不同破坏模式的失效过程,得到了与实验一致的结果。研究还指出,弹靶的冲塞穿甲实际是在高速撞击下,弹体发生花瓣帽形变形失效后继续穿甲靶板的后续结果。 相似文献
15.
平头弹穿透间隙式双层靶的穿甲模式 总被引:6,自引:0,他引:6
平头弹贯穿单层金属靶,随着靶厚的增加和弹速的增高,穿甲模式均可能由剪切冲塞向绝热剪切冲塞转换。因此,对于双层或多层靶的穿甲,其不同层的靶板失效模式可能是不同的。本文中对相关的平头弹穿甲Weldox 700E单层及双层间隙式钢靶的实验数据进行分析,讨论其穿甲模式。弹速较高时,贯穿第1层靶发生绝热剪切失效,弹速降低,贯穿第2层靶板发生绝热剪切失效或剪切冲塞失效, 最终失效模式为绝热剪切和剪切冲塞混杂。 相似文献
16.
We conducted an experimental and analytical study to better understand the mechanisms and dominant parameters for 7.62 mm
APM2 bullets that perforate 7075-T651 aluminum armor plates. The 7.62-mm-diameter, 10.7 g, APM2 bullet consists of a brass
jacket, lead filler, and a 5.25 g, ogive-nose, hard steel core. The brass and lead were stripped from the APM2 bullets by
the targets, so we conducted ballistic experiments with both the APM2 bullets and only the hard steel cores. These projectiles
were fired from a rifle to striking velocities between 600 and 1,100 m/s. Targets were 20 and 40-mm-thick, where the 40-mm-thick
targets were made up of layered 20-mm-thick plates in contact with each other. The measured ballistic-limit velocities for
the APM2 bullets were 1% and 8% smaller than that for the hard steel cores for the 20 and 40-mm-thick targets, respectively.
Thus, the brass jacket and lead filler had a relatively small effect on the perforation process. Predictions from a cylindrical
cavity-expansion model for the hard steel core projectiles are shown to be in good agreement with measured ballistic-limit
and residual velocity data. The results of this study complement our previous paper with 5083-H116 aluminum target plates
in that the ultimate tensile strength of 7075-T651 is about 1.8 times greater than that of 5083-H116. We also present a scaling
law that shows a square root relationship between ballistic-limit velocity and plate thickness and material strength. 相似文献
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M. Adams A. Lashgari B. Li M. McKerns J. Mihaly M. Ortiz H. Owhadi A.J. Rosakis M. Stalzer T.J. Sullivan 《Journal of the mechanics and physics of solids》2012,60(5):1002-1019
This Part II of this series is concerned with establishing the feasibility of an extended data-on-demand (XDoD) uncertainty quantification (UQ) protocol based on concentration-of-measure inequalities and martingale theory. Specific aims are to establish the feasibility of the protocol and its basic properties, including the tightness of the predictions afforded by the protocol. The assessment is based on an application to terminal ballistics and a specific system configuration consisting of 6061-T6 aluminum plates struck by spherical 440c stainless steel projectiles at ballistic impact speeds in the range of 2.4–2.8 km/s. The system's inputs are the plate thickness, plate obliquity and impact velocity. The perforation area is chosen as the sole performance measure of the system. The objective of the UQ analysis is to certify the lethality of the projectile, i.e., that the projectile perforates the plate with high probability over a prespecified range of impact velocities, plate thicknesses and plate obliquities. All tests were conducted at Caltech's Small Particle Hypervelocity Range (SPHIR), which houses a two-stage gas gun. A feature of this facility is that the impact velocity, while amenable to precise measurement, cannot be controlled precisely but varies randomly according to a known probability density function. In addition, due to a competition between petalling and plugging mechanisms for the material system under consideration, the measured perforation area exhibits considerable scatter. The analysis establishes the feasibility of the XDoD UQ protocol as a rigorous yet practical approach for model-based certification of complex systems characterized by uncontrollable inputs and noisy experimental data. 相似文献