共查询到17条相似文献,搜索用时 109 毫秒
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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
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长杆弹对钛合金靶的冲塞实验研究 总被引:1,自引:0,他引:1
对长杆钢弹撞击钛合金靶的绝热剪切冲塞进行了实验研究。观测了初始弹速、弹长和靶厚对于绝热剪切冲塞、靶板塑性弯曲动态响应、弹头局部塑性变形和穿靶后弹体(塞子)剩余速度等的影响。将实验结果与基干热粘塑性双参量失稳理论的绝热剪切冲塞过程的二维数值模拟预示结果进行了比较,两者令人满意地符合,表明在绝热剪切冲塞过程研究中考虑应变率和应变相关的绝热剪切破坏准则以及弹靶耦合效应的重要性。 相似文献
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为研究高硬度钢板抗不同着角钨球的侵彻性能及破坏模式,通过弹道枪进行了?8 mm、?11 mm钨合金球形破片以0°、20°、40°着角撞击厚度为6 mm、8 mm的高硬度钢板试验,得到了极限贯穿速度v50;分析了钨球轴向径向变形及靶板失效模式与撞击速度的关系,发现高硬度钢板失效模式主要为压缩开坑破坏和沿厚度方向剪切破坏。采用有限元方法对试验进行了模拟,验证了数值模型及参数的合理性,并运用数值模拟方法研究了撞击着角对靶板吸能模式影响,结合试验数据,修正已有极限贯穿速度计算公式。结果表明:随侵彻着角增大,极限贯穿速度提高,且着角越大,极限贯穿速度增长越快;随着角增大,靶板吸能模式逐渐由压缩开坑向剪切冲塞过渡,且着角大于50°时,剪切冲塞耗能将超过压缩开坑耗能;修正后极限贯穿速度计算公式适用范围更广、精度更高,具有较好工程应用价值。 相似文献
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为了解杆式弹超高速撞击多层薄钢靶的破坏过程及毁伤机理,开展了克级93W杆式弹正撞击多层Q345钢靶实验及数值模拟研究,通过扫描电子显微镜(scanning electron microscope,SEM)及金相显微镜,分析了超高速撞击实验后靶板材料的微观组织及成分。结果表明,超高速撞击作用下,靶板呈现出“翻唇”穿孔变形、花瓣状塑性变形、撕裂、撞击成坑及鼓包等破坏模式。靶板前3层毁伤以超高速穿孔为主,孔洞数目多但面积小,后几层靶板毁伤孔洞数目少且孔径呈先增大后减小趋势。微观分析表明靶材在强冲击压力下发生晶粒碎化、熔化及再结晶,撞击过程中会形成微孔聚集与微裂纹,可见靶板失效主要是熔融混合物冷却过程中产生的热应力与切应力下的剪切撕裂综合作用的结果。 相似文献
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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
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为更加准确地计算93钨合金弹超高速撞击Q345钢板问题,构建了修正的金属本构模型。引入GRAY三相物态方程描述材料相态变化,采用Johnson-Cook强度模型描述撞击后期材料的力学行为。结合封加波损伤演化模型以及Johnson-Cook失效模型描述不同应力三轴度下材料的拉伸、剪切失效行为;引入曹祥提出的断裂演化模型,描述材料失效后应力归零的过程。通过对比超高速撞击数值模拟结果与实验结果,验证了本构模型的适用性,并进一步分析了典型弹靶撞击条件下破片群的空间分布特征。研究结果表明:基于修正金属本构模型获得的超高速撞击靶板穿孔直径、弹体侵蚀长度、破片群扩展速度结果与实验结果一致;GRAY三相物态方程能够相对准确地给出弹体撞击首层靶板以及剩余弹体、破片群撞击第2层靶板时弹靶材料的熔化情况;封加波损伤演化模型能够准确判断超高速撞击过程中靶板是否产生层裂破坏;综合封加波损伤演化模型、Johnson-Cook失效模型以及曹祥提出的断裂演化模型后,数值模拟获得的破片群撞击后效靶板的穿孔面积与累积数量的统计曲线结果与实验结果一致;获得了典型条件下的柱形93钨弹体超高速撞击Q345靶板破片群空间分布结果,破片群的前端具有较高的质量、轴向动量以及横向动量(绝对值)。 相似文献
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The present paper describes an experimental and numerical study concerning the impact of blunt steel projectiles against harder
steel plates, at impact velocities between 200 and 800 m/s. In contrast with previously published observations, three modes
of deformation and failure of the soft steel projectiles were observed in the present study. These included: Taylor cylinder
mushrooming, sunflower-like petalling and plugging perforation. Individual velocity ranges and the transitions between the
deformation/failure modes are identified by both experiments and numerical simulations. Complex material failure mechanisms
of projectile and target play conflicting roles in the various penetration stages. Johnson–Cook models of strength and accumulative
damage failure are employed in 3D numerical simulation to describe material behavior of both projectile and target. Computational
evolutions of each scenario are offered in detail to understand the deformation and failure of projectile and target plate. 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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本文以Kevlar/环氧树脂层合材料为对象,通过动静态侵彻实验,研究层合板的抗贯穿特性。利用MTS810材料试验机进行准静态侵彻实验,根据测得的加载载荷-位移曲线及靶板的破坏模式,分析了靶板的准静态侵彻行为。实验指出,准静态侵彻时层合板的整体弯曲变形是其主要吸能模式,织物铺层板的吸能量要高于无编织铺层板,表现出更好的抗侵彻性。采用7.62mm口径滑膛枪开展了初速为200~700m/s的弹道冲击实验,讨论了不同弹形弹丸侵彻靶板的效果以及不同铺设方式靶板的抗弹性能和破坏模式。通过与准静态侵彻实验结果的对比,发现靶板的抗侵彻性能和破坏模式与侵彻速度有明显关系。动态侵彻时层合板的破坏局域化,破坏模式多样化。弹形对侵彻效果的影响主要体现于接近弹道极限的低速段。 相似文献
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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
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为研究结构弹体对钢筋混凝土靶的高速侵彻破坏效应,利用口径35 mm弹道炮开展了1 030~1 520 m/s速度范围内的高速侵彻试验,获得了弹体的撞击速度、破坏形态、剩余长度、剩余质量和靶体中的侵彻深度及成坑尺寸等试验数据,分析了侵彻深度和侵彻机理随速度的变化关系。结果表明:在1 030~1 390 m/s的速度范围内,弹体头部磨蚀,磨蚀程度随侵彻速度增加而加剧,侵彻深度随撞击速度近似线性增大;撞击速度在1 390~1 480 m/s范围内,弹体头部严重磨蚀,侵彻深度随撞击速度增加而减小;撞击速度大于1 480 m/s后,弹体严重破碎,侵彻深度急剧下降。针对结构弹体高速侵彻过程中的破坏特点,将侵彻速度划分为刚体侵彻区、准刚体侵彻区、侵蚀体侵彻区和破碎体侵彻区,可为钻地弹结构设计提供参考。 相似文献
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One of the most intricate problems in terminal ballistics is the physics underlying penetration and perforation. Several penetration modes are well identified, such as petalling, plugging, spall failure and fragmentation (Sedgwick, 1968). In most cases, the final target failure will combine those modes. Some of the failure modes can be due to brittle material behavior, but penetration of ductile targets by blunt projectiles, involving plugging in particular, is caused by excessive localized plasticity, with emphasis on adiabatic shear banding (ASB).Among the theories regarding the onset of ASB, new evidence was recently brought by Rittel et al. (2006), according to whom shear bands initiate as a result of dynamic recrystallization (DRX), a local softening mechanism driven by the stored energy of cold work. As such, ASB formation results from microstructural transformations, rather than from thermal softening. In our previous work (Dolinski et al., 2010), a failure criterion based on plastic strain energy density was presented and applied to model four different classical examples of dynamic failure involving ASB formation. According to this criterion, a material point starts to fail when the total plastic strain energy density reaches a critical value. Thereafter, the strength of the element decreases gradually to zero to mimic the actual material mechanical behavior.The goal of this paper is to present a new combined experimental–numerical study of ballistic penetration and perforation, using the above-mentioned failure criterion. Careful experiments are carried out using a single combination of AISI 4340 FSP projectiles and 25[mm] thick RHA steel plates, while the impact velocity, and hence the imparted damage, are systematically varied. We show that our failure model, which includes only one adjustable parameter in this present work, can faithfully reproduce each of the experiments without any further adjustment.Moreover, it is shown that the most common failure criterion based on a critical strain is simply inadequate to reproduce the results, due to the linear nature of the damage evolution. The advantages of the energy-based failure criterion are discussed in detail. 相似文献