共查询到19条相似文献,搜索用时 46 毫秒
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利用金属箔电爆炸驱动聚酯薄膜飞片产生短脉冲冲击波的加载技术(电炮),依据DRM(Delayed Robbins-Monro)实验程序,研究了炸药TATB/粘结剂在各种激励条件下的短脉冲冲击起爆特性,获得了其50%起爆概率条件下的短脉冲冲击起爆阈值,及实验条件下其短脉冲冲击起爆判据为:lnp=0.205-0.87lnτ。并与相同条件下TATB/HMX为基的高聚物粘结炸药的短脉冲冲击起爆阈值进行了比较。结果表明飞片面积和压力脉宽均对炸药的短脉冲冲击起爆阈值有重要影响,与TATB/HMX为基的高聚物粘结炸药相比,TATB/粘结剂更钝感。 相似文献
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利用金属箔电爆炸驱动聚酰亚胺薄膜飞片产生短脉冲冲击波的加载技术,依据DRM(Delayed Robbins-Monro)试验程序,分别测量了以纳米级、亚微米级TATB为基炸药的50%短脉冲冲击起爆阈值,并进行比较。结果表明,以纳米级TATB为基炸药短脉冲冲击起爆阈值比以亚微米级TATB为基炸药的低,在确保炸药安全的前提下,使用以纳米TATB为基炸药更有利降低短脉冲冲击起爆装置所需的能量。 相似文献
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利用光纤探针/光电转换器/示波器技术和楔形炸药块方法,采取电炮驱动薄飞片冲击加载产生高压短脉冲激励的装置,测量了一种以TATB/HMX为基炸药的到爆轰距离,研究了到爆轰距离与初始冲击波压力幅值和脉宽的关系,给出了该炸药的POP曲线和表达式。实验结果有助于了解压力脉宽对钝感炸药的冲击起爆和爆轰成长的影响。对于短脉冲冲击加载,入射压力脉宽对炸药的到爆轰距离影响明显,相同实验条件下,压力脉宽越长,炸药的到爆轰距离越短;相同压力脉宽下,加载压力越高,炸药的到爆轰距离越短。 相似文献
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受热炸药的冲击起爆特征 总被引:2,自引:0,他引:2
设计了炸药驱动飞片起爆受热炸药的实验装置,该装置既能够对实验炸药进行均匀地加热,又能够避免高温对加载炸药的影响。利用设计的实验装置对PBXC10炸药(HMX/TATB复合炸药)进行了14、100、140、160和180 ℃等5种不同加热温度下的冲击起爆实验,测量了该炸药内部压力的成长历程。采用点火增长反应速率方程对PBXC10炸药冲击起爆进行了数值模拟。根据实验结果,标定了不同温度下PBXC10炸药的点火增长模型参数,并给出了模型参数随温度变化的关系式,获得了不同温度下炸药的Pop关系。研究结果表明:PBXC10炸药的冲击波感度随温度的升高而升高,但与HMX炸药相比,其冲击波感度对温度的敏感性明显降低,这是因为PBXC10炸药中的TATB具有较好的降感作用。 相似文献
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根据小隔板试验的拉氏传感器测试结果,用拉氏分析方法求得了粗颗粒包复TNT炸药中的冲击波成长过程和熄灭过程的流场分布,用实验结果确定了点火增长模型中的待定参数。利用拉氏分析方法时,对未反应炸药和已反应产物的状态方程都采用JWL状态方程,使确定的参数可以直接用于有限元程序LSDYAN计算。通过拉氏分析得到了各迹线上的反应度,结果表明,冲击波在熄灭过程中仍能引起炸药的局部化学反应。 相似文献
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为了研究实战环境中多个钨球破片对导弹战斗部(柱壳装药)的冲击起爆问题,采用AUTODYN-3D数值模拟软件,基于单破片撞击柱壳装药模型,建立多破片撞击柱壳装药的模型,开展了不同钨球个数、空间碰撞位置间隔(撞击角θ、轴向球心距l)及时间间隔对冲击起爆特性影响的数值模拟,获得了带壳B炸药的起爆速度阈值。结果表明:相同条件下,随着钨球个数的增加、空间碰撞位置间隔的减小,起爆速度阈值逐渐减小,6个钨球同时撞击的起爆速度阈值约为单个作用下的50%;双钨球作用下,柱壳装药相较于平板装药更难以起爆;双钨球间隔撞击柱壳装药时,起爆速度阈值均随着撞击时间间隔的增大而先减小后增大,最小起爆速度阈值约为同时撞击时的95%,且|θ2|<|θ1|(θ1为第1个钨球的撞击角,θ2为第2个钨球的撞击角)时更容易起爆柱壳装药。 相似文献
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复合材料分层断裂判据及扩展准则研究 总被引:1,自引:0,他引:1
针对现有层间开裂判据及扩展准则未考虑断裂模式耦合性的现状,本文提出了基于模式混合度的复合材料分层断裂判据及扩展准则。依此模型计算了蒙皮/凸缘复合材料加筋层合板结构的分层扩展行为。计算结果表明,所提出的开裂判据及扩展准则能够较好的预测蒙皮/凸缘复合材料加筋层合板结构的断裂力学行为,所得结果对确定含损伤复合材料加筋层合板结... 相似文献
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基于16 mm口径气炮撞击实验,对铝颗粒增强的聚四氟乙烯(polytetrafluoroethylene)/Al(PTFE/Al)冲击反应复合材料的冲击反应阈值开展了研究。为研究不同撞击加载条件下应变率和碰撞应力对PTFE/Al冲击诱发反应的影响,实验中采用铝、钢和低密度聚乙烯(low density polyethylene, LDPE)这3种不同材料的靶板及不同长度的试样,进行不同加载条件下的测试分析。实验结果显示,PTFE/Al材料的冲击诱发同时受到碰撞压力和加载应变率的影响。同时,通过对试样撞靶过程进行数值模拟,并与实验和理论结果进行对比。基于实验数据,拟合出PTFE/Al材料冲击反应的的预测曲线。 相似文献
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Larissa Gorbatikh Stepan V. Lomov Ignaas Verpoest 《Journal of the mechanics and physics of solids》2010,58(5):735-325
Motivated to reveal original mechanisms of failure resistance, we developed a material model that encompasses most reoccurring microstructural features of natural composites. The interesting result of the work is a notion that material failure is governed by the quality of interactions between hierarchical levels in the material microstructure. With intelligent use of the structure, these interactions can be tuned to create a powerful synergetic effect on the material failure behaviour. For example, while exploring different mechanisms of failure initiation in composites with bimodal size reinforcements (an indirect way to model two levels of hierarchy simultaneously) we found that failure initiation could be shifted from stress concentration sites of the higher level to the lower level. One could say that the material behaviour became insensitive to the presence of reinforcements on the higher level—a phenomenon that is counterintuitive to what is commonly known. The new mechanism of failure initiation could only be activated in composites with a highly controlled structural organization—in the studied case, reinforcements of the lower level needed to establish lamellar pathways between reinforcements of the higher level. These pathways lead to formation of an intriguing network-like microstructure. Intelligent communication between reinforcements in such a network created the necessary synergy to change the failure initiation mechanism in a discontinuous fashion. Another finding was that by establishing such a network, tensile stresses near dangerous stress concentration sites were locally transformed into compressive stresses. Resemblance of the revealed mechanism to phenomena on the nano-scale was also discussed. In the course of this work a new method was developed to investigate interactions between reinforcements and their collective input into effective and local properties of a composite. The reinforcement phase was modelled with the use of rigid-line inhomogeneities. 相似文献
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三维显式有限元程序及炸药冲击起爆应用 总被引:1,自引:0,他引:1
冲击和爆炸数值模拟在军事工程和民用领域都应用广泛。基于显式有限元理论,本文介绍了自主研发的三维冲击和起爆流体动力学程序。该程序的功能包含了材料本构、状态方程、炸药反应速率方程和接触碰撞算法,能够模拟复杂条件下结构冲击和炸药起爆问题。由于采用面向对象的编程方法,程序结构相对简单并且容易修改。首先,进行了Taylor杆碰撞数值模拟,并将计算结果与实验结果以及DYNA2D结果进行了比较;接着,基于Lee-Tarver点火增长模型,模拟了冲击加载下裸炸药和带壳炸药的冲击起爆问题。计算结果表明,三维程序计算结果与实验值和商业软件结果都非常吻合,该程序能够较准确地模拟三维结构的冲击和炸药起爆问题。同时,基于面向对象开发的三维计算程序实现了模块化功能,易于后续开发,为冲击和爆炸计算程序的开发提供了参考。 相似文献
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《International Journal of Solids and Structures》2003,40(1):47-72
A digital image processing technique is used for measurement of centroid coordinates of fibers with forthcoming estimation of statistical parameters and functions describing the stochastic structure of a real fiber composite. Comparative statistical analysis of the real and numerically simulated structure are performed. Accompanying of known methods of the generation of random configurations by the random shaking procedure allows creating of the most homogenized and mixed structures that do not depend on the initial protocol of particle generation. We consider a linearly elastic composite medium, which consists of a homogeneous matrix containing a statistically homogeneous set of ellipsoidal inclusions. The multiparticle effective field method (see for references, Buryachenko, Appl. Mech. Rev., (2001a), 54, 1–47) based on the theory of functions of random variables and Green’s functions is used for demonstration of the dependence of effective elastic moduli of fiber composites on the radial distribution functions estimated from the real experimental data as well as from the ensembles generated by the method proposed. 相似文献
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N. A. Kostyukov 《Journal of Applied Mechanics and Technical Physics》1990,31(1):79-85
Translated from Zhurnal Prikladnoi Mekhaniki i Tekhnicheskoi Fiziki, No. 1, pp. 84–91, January–February, 1990. 相似文献