Simulation of explosive welding using the Williamsburg equation of state to model low detonation velocity explosives

Explosive welding is a process for producing bi-metallic plates and tubes. Whilst well established it has been essentially an empirical process. In most welding operations, low-speed explosives such as ammonium nitrate fuel oil (ANFO) mixtures, are used. Such explosives have a low velocity of detonation with an appreciable detonation zone. The usual Jones–Wilkins–Lee equation of state (EOS) is not valid. A more representative EOS is the Williamsburg EOS.Recent work to numerically model the process is described. A notable advance is the use of the finite difference engineering package AUTODYN with a Williamsburg-type EOS to model low detonation velocity ANFO explosive and perlite mixtures. In this work, the Williamsburg EOS was coded as a subroutine in the AUTODYN software package which was then used to simulate most aspects of the explosive welding process. The computed results were validated by explosive welding trials.The phenomenon of jetting and the interfacial waves usually observed in explosive welding were successfully reproduced.     

炸药现场混装技术在爆炸加工中的应用

介绍了国内率先开发成功的适于爆炸加工使用的现场混装低爆速铵油炸药、地面站生产技术及新型铵油炸药现场混装车(BCJX)。BCJX采用独特旋转料仓设计,从根本上解决了粉状铵油炸药现场混装技术难题,开拓了铵油炸药车新品种和新的应用领域。实践证明该项技术安全、高效、低碳,生产的炸药性能良好、完全满足爆炸加工作业要求。     

Examination of copper/stainless steel joints formed by explosive welding

In this study, bonding ability of copper and steel with explosion welding was investigated using different ratios of explosive and different stand-off distance. Experimental studies showed out that, copper and stainless steel could be bonded with a good quality of bonding properties with explosion welding. In the bonding interface, intermetallics were not formed. It was observed that, when explosive ratio and stand-off distance were increased smooth bonding interface was transformed to a wavy bonding interface. As the ratio of explosive and stand-off distance increase, the amplitude and wavelength of wave were increased. It was found that, hardness of bonding interface and outer face of plates were increased because of deformation that was originating from impact the effect. Total interface area increased as a result of wavy interface, which was caused by increased explosive ratio and stand-off distance. In addition, wavy interfaces did not separate after tensile-shearing test. Bending tests applied on bonded samples had different diameters indicated that interfaces of the bonded samples have not any defect. EDS analyses in SEM showed that diffusion did not take place between bonding plates, however, diffusion was observed after annealing of the bonded samples for different times.     

爆炸压实工艺参数对钢管能量与变形的影响

为了指导研究爆炸压实工艺参数的选择,通过改变爆轰速度与装药厚度来改变爆炸冲击能,重点研究爆炸压实工艺参数对钢管能量与变形的影响.研究表明:当其他工艺因素相同、仅爆轰速度不同时,将导致爆轰压力、钢管壁速度、爆炸冲击能、粉末压实能等显著不同,但钢管的变形与能量却几乎不变;当采用爆轰速度极高的黑索今炸药时,由于爆轰压力与爆炸冲击能过高,导致钢管头部被切掉;对硝酸脲炸药而言,随着装药厚度与炸药/钢管质量比增加,钢管的能量与变形、爆炸冲击能与粉末压实能单调增加.     

The influence of a steel rear barrier on the detonation response of a steel covered explosive struck by a steel projectile

Experiments by Weickert showed that the critical impact velocity of a shaped charge jet, required to cause detonation of a steel/explosive/steel laminate, reduced when the explosive thickness reduced. This paper examines the cause of this change using hydrocode simulations with and without a temperature based burn model. The simulations show that the change in critical impact velocity is caused by the reflected shock from the rear plate exceeding the shock at the cover plate. At this point the site of the detonation moves from the cover plate to the rear plate. Further reduction in explosive thickness causes further reduction in critical impact velocity due to the reduced dissipation of the shock reaching the back plate. The change in critical velocity for hemispherical-nosed projectiles is predicted to be not as sharply defined as for flat-nosed projectiles. This is due to a later, third stage reflection from the bulge of the advancing cover plate.     

钛/钢双立式爆炸焊接参数优化

为解决大面积钛/钢爆炸焊接窗口窄,在结合区易出现"过熔"和"射流堆积"等微观缺陷的问题,开展了双立爆炸+轧制综合制造技术,进行了低爆速爆炸焊接用炸药试验优化,发明了一种最低临界爆速爆炸焊接用炸药,设计确定了刚性防护板和柔性防护墙构成的双立综合防护结构及参数,研究了钛/钢爆炸焊接装药厚度窗口.结果表明,双立钛/钢复合板结合界面成波状结合,几乎不存在金属熔化、漩涡等微观缺陷.     

多孔粒状混装铵油炸药爆炸性能试验研究

炸药性能直接影响到爆破的效果,为改善爆破效果,更好地利用炸药的爆炸能,通过现场试验测试混装按油炸药的爆速,得出现场混装铵油炸药最佳配比为柴油占5%,并在最佳配比的条件下,研究了混装按油炸药爆速随装药直径、装药密度及混合后存放时间的变化规律.结果表明,混装铵油炸药爆速随装药直径的增加而增大,当装药直径达到一定值后,爆速趋...     

乳化炸药微观结构对其宏观性能的影响分析

分析乳化炸药内相粒子大小和分布、界面膜、油膜、第三相物质(敏化剂)对其爆炸性能、稳定性、流变性或黏度等宏观性能的影响,建立了微观结构与宏观性能的关联关系,对一些常见现象进行了解释。分析认为,乳化炸药内相粒子的大小与分布,主要取决于机械作用强度和乳化剂的种类和用量两个方面。在相同的配方和工艺条件下,乳化炸药的内相粒子越小,粒径分布越窄,其稳定性和爆炸性能就越好,黏度较大。内相粒子间界面膜和油膜既与内相粒子密切相关,也对乳化炸药的黏度、流动性和稳定性有重要作用。依据热点理论,当气泡或者气泡载体的尺寸在有效范围之内,且分布均匀时,则形成热点的时间接近,有利于爆炸反应的快速激发和传递,宏观上表现为乳化炸药爆轰感度、爆速和猛度等较大。     

乳化炸药微观结构对其宏观性能的影响分析

分析乳化炸药内相粒子大小和分布、界面膜、油膜、第三相物质(敏化剂)对其爆炸性能、稳定性、流变性或黏度等宏观性能的影响,建立了微观结构与宏观性能的关联关系,对一些常见现象进行了解释。分析认为,乳化炸药内相粒子的大小与分布,主要取决于机械作用强度和乳化剂的种类和用量两个方面。在相同的配方和工艺条件下,乳化炸药的内相粒子越小,粒径分布越窄,其稳定性和爆炸性能就越好,黏度较大。内相粒子间界面膜和油膜既与内相粒子密切相关,也对乳化炸药的黏度、流动性和稳定性有重要作用。依据热点理论,当气泡或者气泡载体的尺寸在有效范围之内,且分布均匀时,则形成热点的时间接近,有利于爆炸反应的快速激发和传递,宏观上表现为乳化炸药爆轰感度、爆速和猛度等较大。     

Research on explosive welding of aluminum alloy to steel with dovetail grooves

In order to explore a new method for the explosive welding of aluminum alloy to steel, a 5083 aluminum alloy plate and a Q345 steel plate with dovetail grooves were respectively employed as the flyer and base plates. The parameters adopted in the explosive welding experiment were close to the lower limit of weldable window of 5083 aluminum alloy to Q345 steel. The bonding properties of 5083/Q345 clad plate were studied through mechanical performance tests and microstructure observations. The results showed that the aluminum alloy and steel plates were welded under the actions of metallurgical bonding and meshing of dovetail grooves. The tensile shear strength of 5083/Q345 clad plate met the requirements of the bonding strength of Al/Fe clad plate. The interfaces between aluminum alloy and the upper and lower surfaces of dovetail grooves were mainly welded through direct bonding, and discontinuous molten zone emerged in the local region; while the interface between aluminum alloy and the inclined surface of dovetail grooves was bonded by continuous molten layer. The brittle intermetallic compounds FeAl₂ and Al₅Fe₂ were generated at the bonding interfaces of 5083/Q345 clad plate. The fracture surface of the tensile specimen exhibited ductile and quasi-cleavage fractures.     

钢纤维类型对超高性能混凝土高温爆裂性能的影响

为了探寻可以有效改善超高性能混凝土（Ultra-high-performance concrete,UHPC）抗火性能的钢纤维类型,本文试验测定了不同类型钢纤维（3种普通钢纤维和2种来自于废旧轮胎的再生钢纤维）增韧UHPC及空白组混凝土的从常温至800℃高温爆裂行为和断裂能。结果显示,未掺入任何钢纤维的空白组UHPC试件全都发生了严重高温爆裂,钢纤维可以显著减轻其高温爆裂但却不能避免爆裂的发生,而掺入端钩型普通工业钢纤维（长度为35 mm,直径为0.55 mm）的UHPC呈现出最优的抗高温爆裂性能,其次是掺入未附着橡胶颗粒（RSF）的再生钢纤维（RSFR）增韧UHPC。可见,钢纤维自身性能特征显著影响了钢纤维增韧UHPC的高温爆裂,相同掺量情况下混凝土单位体积内分布密度较大的钢纤维或者分布密度较小但可以显著增加混凝土断裂韧性（断裂能）的钢纤维比较适合应用于具有较高抗火要求的UHPC结构中。     

爆炸焊接用低爆速粉状乳化炸药研究

为降低岩石粉状乳化炸药的爆速,选择了一种HW矿物粉,通过筛混方式将该分散剂与炸药混合,并测定了该分散剂加入量和布药厚度对炸药爆速的影响。结果表明,岩石粉状乳化炸药中掺入44.5%⁵0%的HW矿物粉时,爆速为1913m/s50%的HW矿物粉时,爆速为1913m/s²378m/s,经钢与不锈钢板爆炸焊接试验表明,爆炸结合率达100%,可满足金属爆炸焊接用炸药的要求。     

钛-钢板爆炸焊接的影响因素及炸药配方

爆炸复合用炸药是影响爆炸焊接效果的最主要因素,不同的材料和工艺参数对炸药的爆速、比冲量和能量有不同的影响,其中炸药的密度直接影响复板斜碰撞基板的速度和角度。选用低合金高强度结构钢Q345B和工业纯钛TA2为实验材料,通过理论计算与实验研究,得到了一种较为适合钛-钢板爆炸焊接用的炸药配方,并对钛-钢爆炸焊接影响因素进行了探讨。     

The influence of some factors on steel/steel bonding quality on there characteristics of explosive welding joints

Explosive welding is a solid state process in which controlled explosive detonations force two or more metals together at high pressures. The resultant arrangement is joined with a high quality metallurgical bond. The aim of this study was to investigate of strength of explosive welding metals which had same chemical compositions. In this study, it was taken different welding interfaces (straight, wavy and continuous solidified-melted) with changing explosive welding parameters (stand-off distance (s), explosive loading (R) and anvils). Joined metals were investigated in heat treatment and non heat treatment conditions. Microstructures, microhardness, tensile shear strength and bending test results were reported. Effect of anvil on explosive welding process was evaluated in joining/no joining performance. It was shown that bonding interface changed from straight to wavy structure when explosive loading and stand-off distance were increased. On wavy interface, when explosive loading was increased wavy length and amplitude increased. Results of tensile shear and bending tests showed that heat treated specimens have more strength than which of unheat-treated ones. According to tensile shear test results, straight and wavy interfaces had similar strength. Also, bending zone has shown some cracks after the bending test of unheated specimens.     

An investigation of mechanical and metallurgical properties of explosive welded aluminum-dual phase steel

The aim of this paper is investigation of microstructure and property relationship in aluminum-HSLA steel and aluminum-dual phase steel bimetals fabricated by explosive welding technique. Dual phase steel was produced by intercritical annealing and water quenching from 1.45Mn-0.2Si-0.186C HSLA steel. Hardness, tensile shear strength, tensile strength, toughness and microstructure of explosively welded aluminum-HSLA steel and aluminum-dual phase steel were evaluated. Both bimetals have a straight bonding interface. It was also seen that plastic deformation of dual phase steel was higher than HSLA steel near interfaces of bimetals. The hardness was increased near the bond interface of bimetals. Tensile and tensile shear strength tests showed that aluminum-dual phase steel is superior than aluminum-HSLA steel. Also, impact toughness of aluminum-dual phase steel was found significantly higher than that of aluminum-HSLA steel.     

An Euler–Lagrange particle approach for modeling fragments accelerated by explosive detonation

In this paper, a method is proposed for modeling explosive‐driven fragments as spherical particles with a point‐particle approach. Lagrangian particles are coupled with a multimaterial Eulerian solver that uses a three‐dimensional finite volume framework on unstructured grids. The Euler–Lagrange method provides a straightforward and inexpensive alternative to directly resolving particle surfaces or coupling with structural dynamics solvers. The importance of the drag and inviscid unsteady particle forces is shown through investigations of particles accelerated in shock tube experiments and in condensed phase explosive detonation. Numerical experiments are conducted to study the acceleration of isolated explosive‐driven particles at various locations relative to the explosive surface. The point‐particle method predicts fragment terminal velocities that are in good agreement with simulations where particles are fully resolved, while using a computational cell size that is eight times larger. It is determined that inviscid unsteady forces are dominating for particles sitting on, or embedded in, the explosive charge. The effect of explosive confinement, provided by multiple particles, is investigated through a numerical study with a cylindrical C4 charge. Decreasing particle spacing, until particles are touching, causes a 30–50% increase in particle terminal velocity and similar increase in gas impulse. Copyright © 2015 John Wiley & Sons, Ltd.     

多孔粒状铵油炸药爆炸热化学计算与分析

运用B-W法建立多孔粒状铵油炸药的爆炸反应方程式,依据盖斯定律计算定容爆热,加权法计算爆炸产物的摩尔定容热容,研究计算得出露天多孔粒状铵油炸药的比容为970.10L/kg、爆热为-3840.67kJ/kg、爆温2787K;并讨论分析了氧平衡值对多孔粒状铵油炸药热化学性能的影响情况。     

基于TANPyO的PBX炸药爆炸性能研究

为研究高能量密度材料TANPyO基PBX的爆炸性能,基于TANPyO炸药,分别添加黏结剂氟橡胶F_(2311)、丁腈橡胶(NBR)以及氟橡胶F_(2311)与丁腈橡胶(NBR)按比例混合而成的黏结剂,采用溶液-悬浮-蒸馏法制备3种TANPyO基的PBX炸药。通过扫描电镜对样品进行微观表征,测试其爆速和感度,并采用聚能装药形式进行爆炸威力和钢靶射孔穿深试验。试验结果表明,3种TANPyO基PBX样品爆炸性能良好,满足低易损炸药高能钝感要求,爆速约7 200 m/s,穿孔深度达到120 mm以上,具有良好的撞击感度与摩擦感度;尤其以添加F_(2311)+NBR的TANPyO基PBX样品测试效果表现最佳,爆速达到7 186 m/s,穿深达到138 mm,并且其威力侵彻深度和体积分别达到8701炸药的93.4%和70.6%。TANPyO基PBX样品性能指标既满足钝感炸药又符合高能混合炸药,从而说明TANPyO能够成为一种新型高能钝感含能材料。     

废食用油在混装多孔粒状铵油炸药中的应用

为了解决混装多孔粒状铵油炸药生产中可燃剂轻柴油使用量大、价格高、不可再生等问题,提出将废弃食用油脂与轻柴油制备成混合油相代替纯轻柴油用于混装铵油炸药生产。研究分析了多孔粒状硝酸铵对混合油相吸附率随废弃食用油脂占比的影响,混装铵油炸药不同配比及混合油相中废弃食用油脂不同占比下炸药爆速的变化规律。结果表明:废弃食用油脂不能完全替代轻柴油用于多孔粒状铵油炸药生产,而一定配比的混合油相用作可燃剂能够生产出爆速合格的铵油炸药,与用纯轻柴油相比较,明显降低了生产成本。     

Enhanced work hardening in Hadfield steel during explosive treatment

This paper presents results concerning Hadfield steel subjected to explosive treatment and compression, respectively, with the purpose of clarifying the difference between dynamic and static deformation behaviors. A Hadfield steel sample that was deformed to a lower strain at an exceptionally high strain rate exhibited the same hardness as a sample that was deformed to a higher strain at a low strain rate. A deformation model based on in situ deformation has been developed, whereby the enhanced work hardening during explosive treatment is attributed to the deformation of the grains being mainly accommodated by the curvature of the grain boundaries and shape change of the surrounding grains in their original positions, without obvious macroscopic deformation.