【作者】 林加剑；

【导师】 任辉启； 沈兆武；

【作者基本信息】 中国科学技术大学 ， 工程力学， 2009， 博士

【摘要】 作为一种反坚固目标技术,爆炸成型弹丸(以下简称为EFP)在末敏弹武器系统中发挥着重要的作用,随着各种新型防护技术的迅猛发展,对EFP的技术要求也越来越高。为对付不同场合下的目标,出现了许多不同结构形状药型罩形成的EFP,通过对药型罩几何形状及装药结构的不断改进,使其具有更快、更远、更准的破甲能力。在大炸高条件下,EFP的飞行稳定性将直接影响到打击目标的精度,如何保证在远距离下稳定飞行成为制约该技术进一步应用的难点之一。尾翼由于可以提高EFP的飞行稳定性,因此,研究人员利用多种方法实现带有尾翼的EFP,包括多点起爆法、异形壳体法、波形控制器和三维药型罩技术。本文提出隔板法形成尾翼,该方法主要是通过在药型罩上粘贴隔板,利用隔板改变爆轰波波阵面的结构形状,使药型罩上的爆轰压力发生规律性变化,最终形成尾翼型EFP。首先在理论上分析了隔板对药型罩微元上压垮速度和压力的影响规律,通过对影响规律的分析证明隔板法形成尾翼的可行性。采用铝为隔板材料,在药型罩上对称布置四个几何尺寸相同的隔板,通过回收实验得到带有四个尾翼的EFP。结合实验条件,采用LS-DYNA对隔板法形成尾翼进行数值模拟,根据数值模拟结果,在药型罩上选取具有一定代表性的微元,根据药型罩微元上速度和压力的变化曲线,对贴隔板法形成尾翼的可行性作了进一步的分析。结合不同的药型罩形状,对两种EFP速度工程算法及其应用范围进行了分析对比,并将实测值和数值模拟进行对比,同时,从能量守恒法出发,推导了贴隔板法形成尾翼EFP的速度计算方法,并将理论计算结果与数值模拟结果进行分析对比。根据EFP空中飞行衰减规律,编制了MATLAB计算程序,通过自编程序可以计算不同药型罩及装药结构的EFP速度,并可以得到不同飞行距离下的EFP速度。由于EFP速度是评价其破甲威力的一个重要指标,因此,分析影响EFP速度的主要因素在战斗部设计中具有重要的指导意义。根据EFP速度的计算方法,首先在理论上计算出12种不同方案的大锥角药型罩EFP的速度,并结合数值模拟得到结果,采用灰色理论对影响EFP速度的因素进行分析,建立各个因素与EFP速度之间对应的灰关联度矩阵。通过对灰关联度矩阵的分析,得到影响EFP速度的主要因素。EFP对靶板的侵彻是一个非常复杂的物理力学过程,其侵彻过程不同于刚性弹体对靶板的侵彻,也不同于高速流体对靶板的侵彻,是一种介于刚性弹和射流之间的高速柔性侵彻体。通过实验对尾翼EFP和准球形EFP的侵彻性能进行了相应的研究,并通过数值模拟得到准球形EFP侵彻钢靶的全过程,详细分析了EFP侵彻靶板时三个典型的阶段。有效装药研究对提高炸药的能量利用率及减轻战斗部重量具有重要的意义,如何在合理的装药结构下获得最大的动能对EFP战斗部的优化设计具有一定的研究价值。通过对有效装药的理论分析,以大锥角药型罩为研究对象,结合数值模拟对大锥角型药型罩在不同装药长径比下EFP速度和能量利用率的变化规律进行了分析。最后,利用LS-DYNA对不同船尾型装药结构进行数值计算并提出两种装药结构优化方案。更多还原

【Abstract】 As a technology of inversing solidity target,the EFP play an important role in the weapon system of terminal-sensitive projectiles.The requirement of EFP technology become more higher with the rapid development in new-style protection technology.In order to coping with different target in different situation,many EFPs are appeared which is formed in different structure shaped charge liner.The damage ability of EFP becomes more rapid more far and more accurate by changing the geometry of shaped charge liner and charge structure.The flight stability of EFP will directly affect attacking precision in the condition of high stand-off.How to guarantee the flight stability under long distance becomes a difficult point of restricting the applicttion of EFP technology further.Fins is able to enhance the flight stability,so many researchers realized EFP with fins by using of various methods including multi-point initiation,special-shaped shell,wave-shaped and three-dimensional liner. This paper presents a way to form fins by using of pasting clapboard.The structural shape of detonation wave front is changed by clapboard which is affixed on the liner, then the detonation pressure on the liner results in regular changes which lead to form EFP with fins.The influence law of velocity and pressure on liner is anlysised in the theory,and then the feasibility of clapboard methods is confirmed by anlysising the influence law. The EFP with four fins is obtained by recovery experiment.Four piece of aluminium as a clapboard material is symmetrical affixed on the liner in this experiment.The numerical simulation on clapboard methods forming fins is simulated by LS-DYNA according to the condition of the experiment.Based on the results of the numerical simulation,some liner infinitesimal elements with a certain reperesentativeness is selected.The feasibility of clapboard methods is anlysised further from the velocity and pressure curve on the liner.Based on the energy conservation and momentum conservation,combined with different geometry of shaped charge liner,compared with experiment and numerical simulation results,two engineering algorithms and the application range of EFP are comparative analysised.The calculation method of EFP velocity which is formed by clapboard methods is derived,at the same time;the results between theoretical calculation and numerical simulation are compared.The velocity of EFP is an important index to assessment on the penetration power,so it is very important to anlysis the influencing factors of the EFP’s velocity.Based on the calculation method of EFP,the velocity of large cone angle liner of twelve different schemes is calculated in the theory,combined with the results of numerical simulation,the influencing factors of the EFP’s velocity are anlysised by grey theory,and the grey correlation degree matrix between the EFP’s velocity and every influencing factors is established, then the major influencing factors are obtained.It is a very complex physical and mechanical process about the EFP penetrating target plate.The process is different from the rigid projectile body and high velocity jet penetrating target plate which lies between them.The penetration performance of EFP with fins and pseudo-spherical EFP are researched by experiment,and the whole process of the EFP penetrating target plate is obtained by numerical simulation,at the end,three typical stages of penetrating process is anlysised in detail.The study on effective charge has a very important significance in increasesing the ratio of energy utilization and reducing the weight of warhead.How to obtain the maximum kinetic energy under reasonable designing the charge structure has a certain research value in optimization designing the EFP warhead.The large cone angle liner is taken as a research object,combined with theoretical analysis and numerical simulation on effective charge.The change law of EFP’s velocity,kinetic energy and the ratio of energy utilization are anlysised which is obtained by the large cone angle liner under different length-diameter ratio of shaped charge.At the last, the numerical simulation about different ship-tail shaped charge is calucated by LS-DYNA and corresponding optimization scheme of charge structure is presented.更多还原