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In this contribution we present results from a case-study, which was performed in collaboration between geophysicists and explosive ordnance disposal technicians at the Rohožník military training range in SW Slovakia. The aim of this study was to locate a deep-penetrated unexploded Mk-82 aerial bomb using high-definition digital magnetometry. The location where this bomb had entered the ground was known but its final position needed to be determined so that a safe excavation and disposal could be conducted. However, the detection of this unexploded ordnance object was complicated by the presence of intense magnetic interference from a number of near surface ferrous items including non-explosive test bombs, fragmentation and other iron junk. These items contributed a localised, high amplitude of magnetic clutter masking any deeper source. Our strategy was to approach the problem in three stages. First, we used magnetic data to locate the near surface items. After the detection and before the excavation of the searched objects, two quantitative interpretation methods were used. These involved an optimised modelling of source bodies and the application of a 3D Euler deconvolution. Both methods yielded acceptable results, but the former was found to be more accurate. After the interpretation phase, many of the items were then safely excavated and removed individually. A second magnetic mapping was then performed and from this data which was now significantly less cluttered, we were able to identify but not quantify, two deep source items and to confirm that all remaining near surface items were significantly smaller in size than a Mk-82 bomb. As the remaining near surface sources were interpreted as being contained within the surface one metre of soil and being small they could be assured to be non-explosive, it was considered most practical to mechanically excavate and remove this soil and the remaining objects contained.

When considering the bomb explosion damage effect, the air shock wave and high-speed fragments of the bomb case are two major threats. In experiments, the air shock wave was studied by the bare explosives superseding the real cased bomb; in contrast, the bomb case influence was ignored to reduce risk. The air explosion simulations of the MK84 warhead with and without the case were conducted. The numerical simulation results showed that the bomb case significantly influenced the shock wave generated by the bomb: the spatial distribution of shock wave in the near field changed, and the peak value of shock wave was reduced. Breakage of the case and kinetic energy of the fragmentation consumed 3 and 38% of the explosion energy, respectively. The increasing factors of the peak overpressure induced by the bare explosive on the ground and in the air were 1.43–3.04 and 1.37–1.57, respectively. Four typical stages of case breakage were defined. The mass distribution of the fragments follows the Mott distribution. The initial velocity distribution of the fragments agreed well with the Gurney equation.

In our previous work, we developed a new terminal-ballistics model developed for artillery high explosive projectiles with natural fragmentation. Lethal radius is here defined as the distance from the detonation point where the effective fragment (80 J) density is 1 frag/m2. In the model, the vertical position of the projectile upon impact is assumed, which means that the lethal radius defines a circular lethal zone (maximum lethal zone of the projectile on the ground). In the research, presented in this paper, we have applied the model to mortar projectiles and rocket warheads, which have different designs compared with classic artillery projectiles. The results from the model, compared to the available experimental results from the quarter-circular arena (used in our country), showed satisfactory accuracy for these types of munitions.

The Islamic Movement of Sudan established the first Islamist regime in the Sunni Islamic world by a military coup. By seising state power, the Islamic Movement tried to overhaul the political syste...

Soon after his move, in 1855, to the Channel island of Guernsey, Victor Hugo bought a large house, which he called Hauteville House after the quarter of Saint Peter Port in which it was located. Ov...

At present, the issue of creating means of destruction of domestic production in Ukraine, including rocket- propelled anti-personnel grenade launchers equipped with different warheads (thermobaric, assault, fragmentation and incendiary) is acute. With the advent of new incendiary, thermobaric agents and explosives, the development of multi-purpose rocket-propelled grenade launchers has become one of the promising trends. All of the above is proven by the experience of the Anti-Terrorist Operation/Joint Forces Operation in eastern Ukraine. Analysis of flame troops combat operations during the anti-terrorist operation showed the need to intensify efforts to develop new rocket-propelled anti-personnel grenade launchers with thermobaric, assault, fragmentation and incendiary warheads. Leading specialists from the Russian Federation and Western countries also came to this conclusion. Thus, in recent years in Russia there have been developed, passed state tests and adopted RGSH-1 with a modular warhead in the thermobaric version, RGSH-2 rocket projectile with thermobaric warhead and RPG-32 "Barkas" equipped with thermobaric or tandem cumulative grenade. Nowadays, several enterprises of the defense complex, one of which is the ТОV "Vognyana Varta", are dealing with the creation of a modern domestic rocket-propelled anti-personnel grenade launcher in Ukraine. ТОV "Vognyana Varta" on its own initiative has been developing a rocket-propelled anti-personnel grenade launcher with different warheads using new incendiary, thermobaric mixtures and explosives. The classification of rocket-propelled grenade launchers (flamethrowers) is carried out. The design of modern ammunition to rocket-propelled grenade launchers (flamethrowers) and types of warheads for them are considered. Calculations of a solid-propellant rocket engine for modern rocket-propelled grenade launchers (flamethrowers) are given.

The simplicity and versatility of the Gurney model has led to its widespread adoption for the calculation of peak fragment velocity of explosively-driven munitions such as fragmentation warheads an...

The impact experiment of penetrator with enhanced lateral efficiency (PELE) penetrating the metal target plate was carried out to study the fragmentation characteristics of PELE shell made of tungs...

Fragmentation is the process of breaking of solid in-situ rock mass into several smaller pieces which are being excavated or moved by material handling equipment. It is the major concern of any blasting operation. Information on the degree and size distribution of fragments within a blasted rock mass is essential for efficient loading, transport, crushing and milling operations. An automated image based granulometry system WipFrag is used to analyze the digital image of rock photographs to determine grain size distribution. The method was tested in Dongri Buzurg open-pit manganese mine of Maharashtra (India). WipFrag software was found to be useful for fragmentation analysis of blast fragment sizes in very short interval of time

In understanding how groups overcome collective action problems of mass mobilisation in civil wars, a joint-production explanation was put forth in the civil war literature. According to this expla...

Blasting in an underground mine produces potentially harmful elastic stress waves that propagate down thewalls and back of the entry. Stemming may be used to maximize the effectiveness of an explosive at the faceand minimize the magnitude of the elastic waves that propagate down the entry and also reduce unnecessarydischarge. Stemming is necessary to stop the explosive energy from escaping through the upper part of blastholes in underground mines.

The Gurney method is widely used in the conceptual design stage of explosive fragmentation warheads employed in various weapons systems. This method states that the peak fragment velocity ( V 0 ) is a function of the Gurney velocity ( 2 E G ) and the charge-to-metal weight ratio ( C / M ). The current study is concerned with finding a practical approach for computing the Gurney velocity of pure and mixed high explosives which will eventually help warhead designers to select the best explosive to fulfill the needs of a particular mission. Using multiple regression analysis technique, a four-variable model was derived and used thereafter to estimate the Gurney velocity of aluminized and non-aluminized explosive formulations. The results show that the new model is particularly accurate in predicting the Gurney velocity of combined effects explosives, which are relatively a new class of high blast, high metal acceleration capability explosive compositions.

A smooth particle hydrodynamics (SPH) model was used to simulate the fragmentation process of the jacket during penetrator with lateral efficiency (PELE) penetrating the metal target plate to study the fragmentation characteristics of PELE jacket made of tungsten alloy. The validity of the SPH model was verified by experimental results. Then the SPH model was used to simulate the jacket fragmentation under different impact velocity and thickness of target plate. The influence of impact velocity and thickness of target plate on the jacket fragmentation was obtained by analysing the mass distribution and quantity distribution of the fragments formed by the jacket. The results show that the dynamic fragmentation of tungsten alloy can be simulated effectively using the SPH model, Johnson-Cook strength model, maximum tensile stress failure criterion and stochastic failure model. When the thickness of target plate is fixed, the greater the impact velocity, the greater the pressure produced by the projectile impacting the target plate; with the increase of impact velocity, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. When the impact velocity is constant, the greater the thickness of the target plate, the longer the pressure duration by the projectile impacting the target plate; with the increase of the thickness of target plate, the mass of residual projectile decreases, the number of fragments formed by fragmentation of jacket increases linearly, and the average mass of fragments decreases exponentially. The numerical calculation model and research method adopted in this paper can be used to study the impact fragmentation of solid materials effectively.

The two main rebel groups in the Second Congo War (1998–2003) evolved in remarkably different ways. While the MLC maintained organisational cohesion throughout the war, the RCD split into two rival groups within less than a year. The larger of these rivals then remained cohesive, whereas the smaller group experienced further fragmentation. This article draws on interviews with key protagonists to show that these cross-group differences resulted from different patterns of state sponsorship. Fragmentation occurred when the intra-group distribution of power between a rebel leader and an internal rival hung in the balance because external troops supported both sides. Postprint

In addition to its usage as a top attack ammunition in the battle field against troops, 120 mm mortar bomblethas been recently used in the terror attacks against military shelters and civil constructions. This research studiesthe protection of vehicle and personnel military shelters against mortar fragmentation warhead projectile and it’sdestroying effects. The mortar warhead threat combines both blast load and ballistic fragment penetration effects. Composite structure layers are proposed herein to be integrated with concertina walls to achieve full protection against the mortar projectile destroying effects. The current paper investigates the ability of the proposed layers to stop the mortar’s fragments and to mitigate its blast load. The velocity and the mass distribution of the produced projectile fragments were estimated using Split-X software. Besides, the ability of the proposed protection layers to stop the fragments and mitigate the blast wave was evaluated using AUTODYN hydrocode. A static firing test was then performed to validate the theoretical results and verify the effectiveness of the proposed protection added layers. The current study showed that the proposed composite layers are sufficient to protect the military shelters from the mortar’s destroying ballistic effects.

In the design process of the blast-fragmentation warhead with preformed fragments, there are two key factors: the modeling and arrangement of the preformed fragments. These factors determine the accuracy of lethality assessment on the blast-fragmentation warhead with preformed fragments. Presently, there are some problems in the design process of the warhead, such as repeated modeling and low efficiency. This paper studies the modeling of blast fragmentation with preformed fragments. Based on the analysis of warhead structure and the technology of digital modeling, the idea of warhead modeling based on basic primitives and the arrangement method of preformed fragment modeling are proposed. In addition, by means of Visual C#, Direct X, and Direct3D, a digital modeling system based on the blast-fragmentation warhead with preformed fragments is developed, and then a warhead is taken as an example to realize the digital modeling. The case analysis shows that the digital modeling technology based on the blast-fragmentation warhead with preformed fragments completed the rapid and accurate modeling of the preformed fragment warhead, which lays the foundation for the accuracy of lethality assessment.

We present evidence that in ~ 1650 BCE (~ 3600 years ago), a cosmic airburst destroyed Tall el-Hammam, a Middle-Bronze-Age city in the southern Jordan Valley northeast of the Dead Sea. The proposed airburst was larger than the 1908 explosion over Tunguska, Russia, where a ~ 50-m-wide bolide detonated with ~ 1000× more energy than the Hiroshima atomic bomb. A city-wide ~ 1.5-m-thick carbon-and-ash-rich destruction layer contains peak concentrations of shocked quartz (~ 5–10 GPa); melted pottery and mudbricks; diamond-like carbon; soot; Fe- and Si-rich spherules; CaCO3 spherules from melted plaster; and melted platinum, iridium, nickel, gold, silver, zircon, chromite, and quartz. Heating experiments indicate temperatures exceeded 2000 °C. Amid city-side devastation, the airburst demolished 12+ m of the 4-to-5-story palace complex and the massive 4-m-thick mudbrick rampart, while causing extreme disarticulation and skeletal fragmentation in nearby humans. An airburst-related influx of salt (~ 4 wt.%) produced hypersalinity, inhibited agriculture, and caused a ~ 300–600-year-long abandonment of ~ 120 regional settlements within a > 25-km radius. Tall el-Hammam may be the second oldest city/town destroyed by a cosmic airburst/impact, after Abu Hureyra, Syria, and possibly the earliest site with an oral tradition that was written down (Genesis). Tunguska-scale airbursts can devastate entire cities/regions and thus, pose a severe modern-day hazard.

The purpose of the present study was to evaluate the content of lead in carcasses of wild boars shot with lead bullets, in comparison with that of copper caused by lead-free ammunitions. Radiographic images of hunted boars were obtained in order to assess the degree of bullet fragmentation in the carcasses. Samples of meat were collected from different body areas at increasing distance from bullet trajectory, to be analysed by ICP-MS for lead and copper levels. In wild boars shot with lead ammunitions, a massive dispersion of bullet fragments and very high lead levels were detected. By contrast, in wild boars killed with copper ammunitions no radiographic signs of bullet fragmentation were observed. Copper ammunitions seem therefore a safer alternative to standard lead-core ones, due to their minimal fragmentation and the relatively low toxicity of this metal.

This article assesses the emergence of the new groups, organizations and protests that have emerged since the financial crisis and asks whether we can understand these as a fresh developmen...

The investigation of the fragmentation properties along the axis of a metal shell under explosive loading is valuable for understanding the fragment formation principles of a warhead. To investigate the axial fragmentation distribution of a metal shell, herein the fragmentation from different axial positions of a metal shell under single-end detonation conditions was analyzed based on the microelement method. Moreover, a corresponding simplified model for the average fragment mass was established. The fragment distribution characteristics at different axial positions and the internal features from the metal shell fragmentation was analyzed by designing an experiment for fragment segmented recovery and fragment perforation occurring in the fragmentation of a 1045 metal steel cylinder shell filled internally with 8701 high explosives. The similarity between the fragment perforation contour and the projected contour of fragments was applied to verify the accuracy of the simplified model of the fragmentation along the axial direction, which can provide an important reference for the design of warheads and the performance of protective architecture.

Water in the blasthole causes adverse effects on blasting performances, e.g., the incomplete explosion of explosive and toxic fume generation. It is normally pumped out before explosive loading to prevent explosive deterioration. In this study, a new blasting concept – water deck blasting (WDB) is introduced which sealed the water at the blasthole bottom to prevent adverse effects of water as well as maximise the beneficial effect of water on rock breakage performances. A field experiment was conducted in a quarry , bench blasting including twenty-three watery holes among 139 blastholes. Promising results were observed as there was no evidence of toxic fume during blasting and achieved a competent level of fragmentation with even toe-cut at the bottom level. The WBD and a normal charge blast were simulated using ANSYS/AUTODYN and multi-peak oscillations were investigated for the WBD. The advantageous rock breakage performances of the relatively small amount of water rather than the amount of explosive have not been verified but have been discussed referring to the extreme water and the steam explosion phenomenon. The WBD blasting method expects to bring advantageous effects to surface mine blasting.

In the case of an uncontrolled demolition or a terrorist attack no prior knowledge is usually available as to what the exact explosives is and what the exact charge weight is. As well, in most cases the authorities have no idea what the target is to be in advance of an attack. For a designer to design a structure to minimize the damage in such cases is somewhat difficult if not impossible but, nevertheless, it must be done. Once the explosive, either as an improvised explosive device or vehicle improvised explosive device, has detonated the normal aftermath of such events such as fragmentation, primary and secondary fires, ground cratering and building collapse are all obvious. From a designers’ point of view, the starting point is to understand in detail all building collapse mechanisms to be able to design for such events and so allow time, if possible, for all those caught inside a building to escape and for structural damage to be minimized. To obtain such design parameters the designer must refer to past uncontrolled demolitions on Australian soil or in countries close by to gauge the most likely threat. Prior to design commencing one also must have clear criteria and strategy in mind to be able to complete a suitable design to ensure his obligation to allow time for people to escape from its collapse is met and damage is minimized. Designers not only have to address new building designs to withstand blast and ballistic loadings but also how to retrofit existing buildings cost effectively against such blast and ballistic loadings. Detailed lists of required criteria and strategies that are necessary so at to arrive at a suitable design for any blast or ballistic loadings likely to being applied to a structure are provided within the paper based on all aspects of an uncontrolled demolition (explosion) that may confront a designer.

In cases of terrorist bomb attacks, the issue of victim identification is the principal aim. For investigators and justice, terrorists must also be identified in a timely manner. The fragmentation of bodies caused by explosive devices however makes this operation difficult. The cases presented correspond to six autopsies of perpetrators carrying explosives. Their explosive belts produced different body sections on areas correlated with the location on the body of carrying explosive charges. Indeed, cross-sectional areas are the signature of the level of explosive devices on the body, and some fracture features through the damage of certain areas of constitutional weaknesses are specific elements to consider. These elements can allow a quick distinction between victims and terrorists, in order to assist in the medico-legal process of identification.

The use of precision-guided artillery rounds has increased in recent years, but analytical models within simulations that enable effect analysis and tradeoff analysis between precision and conventional munitions are lacking. This paper develops an analytical model of precision-guided fragmentation munitions effects for low-resolution simulations. A modification of the commonly used Carlton Damage Function, called the Klopcic Hybrid approach, is implemented within a baseline simulation that addresses the Carlton Damage Function’s shortcomings and implementation issues. A designed experiment using a range of parameters accounting for many weapon types is then performed using a space filling design whose results are used in constructing an empirical model. The baseline simulation for the magnitude of target location error, a trait not normally modeled in simulations but critical in the determination of precision munition use, is addressed. A response surface is developed that analytically models the nonlinear behavior of the dependent variable. Defendable and traceable response functions are developed for varying precision munition types and target location error ranges that are flexible to a broad range of munition capabilities.

A typical aerial bomb has high explosive packed in a metallic cylindrical shell. The bombs explode due to the detonation of high explosive either on impact or in proximity to the target. The metallic shell on explosion disintegrates into various small fragments which strike the various target fields contributing to the fragmentation effect. The present work mainly focuses on finite element (FE) simulation of aerial bomb impact on target fields like sand, concrete and steel using Ansys explicit dynamics for imported three-dimensional model of aerial bomb using solid edge. FE simulation was carried out to find stresses and corresponding deformations within the bombshell for three different target fields. Further, the impact simulation results were compared for the deformation and stress limits of the bombshell material.

Drilling and blasting play an important role in operation cycle of a mine or quarry. Optimum blast design plays a pivotal role to achieve maximum utilization of explosive energy and blast fragmentation. Only 20 to 30% of explosive energy is utilized for fracturing and fragmentation of rock, and the rest of the energy is converted in noise, air overpressure, ground vibration, etc. It has been observed that using the low-density explosive may reduce the deleterious effect of engineering blasting with desired blast fragmentation. This paper substantiates this fact wherein distinct explosive energy utilization enhancement has been achieved with the use of low-density explosive and reduces ground vibration. This paper outlines the on-field assessment of low-density explosive in Quarry AB of Tata Steel West Bokaro Division. It is a solid sensitized emulsion blend. It comprises products designed for blasting in dry, dewatered, and wet blast-hole applications. Low-density explosive provides the capability to better match explosive performance to ground conditions. Being a low-density, low-energy explosives, it provides an added benefit of reducing the environmental effects of blasting. The key objective of the field assessment was to test the on-field performance of the new low-density bulk products and its effects on blast-induced ground vibration and air overpressure.

An increasing number of munitions now show less violent responses than detonation in cook off or impact scenarios. The detonation of a warhead typically leads to well reproducible fragmentation effects. Deflagrations and explosions may still rupture the munition casing, but fragmentation is typically limited to just a few large fragments with a relatively low velocity. Fragmentation modeling has evolved significantly with increasingly realistic predictions, even for less violent explosions and deflagrations. Although deflagrating warheads produce only a few fragments, these fragments may reach large distances. Estimates of deflagrating warhead fragment trajectories can be done using platelike fragments. Conventional safety distances are not well suited for this situation. For illustration purposes a simple model of Individual and Group Risk was applied to a case study comparing detonating and deflagrating warheads.

Quest for range enhancement has led to development of Artillery Guns which are capable of generating high pressure levels in the tube to propel the projectiles at increased muzzle velocity. This leads to increased level of launch forces the projectiles are subjected to. Survivability of the Extended Range Full Bore (ERFB) projectile body has been assessed for exploitation with different class of 155mm Artillery Guns. An approach for development of high strength ERFB projectile using existing geometry, raw material and manufacturing set up has been devised, wherein heat treatment process has been altered suitably. Large scale destructive testing of prototypes for evaluating the enhancement in mechanical properties has been carried out. The approach has been validated by conducting dynamic evaluation trials. Static trials for comparing the fragmentation effect of existing and high strength ERFB projectiles have been carried out and the latter have been found to exhibit better performance.

This paper presents theoretical assessment of controlled fragmentation (CF) warhead and its application for (Unmanned Aerial Vehicle) UAV. It is a great challenge to the designer to make small warheads with precision for defeat ofground targets. Attempts have been made to optimize the performance parameters of small warheads to be used in UAVs for defeat of specified ground targets. Warhead performance parameters are characterized by mass distribution and special distribution, velocity of fragments and penetration performance of fragmets against ground targets. Lethality of warhead depends on explosive filling, case materials and controlled fragmentation techniques. Parametric studies are carried out to improve the performance parameters in the best possible manner. The theoretical model shows that the warheads in the weight class of 1kg can defeat simulated targets of 5-mm thick mild steel at a lethal radius of 10m, generating more than 250 numbers of 1 to 2-g compact fragments in beam angles of the range of 100-120.To check out the efficacy and effectiveness, two cylindrical warhead prototypes using controlled fragmentation were fabricated and tested in similar conditions.

The artillery rocket system is the sophisticated type of defence system. One of it is Preformed fragment type warhead. The tungsten fragments-ball, needles, cubes etc. are arranged around the charge mass in such a way that on initiation the fragments are propelled with very high velocity by rupturing the ballistic casing. These ballistic casing can be made of different materials according to the aerodynamic loading, structural loads etc. Generally used casing materials are FRP, steel, aluminium. Due to difference in the material properties the fragment velocity, energies and the pressure generated are affected. To study these effect static and dynamic trails prove costly and time consuming. So an alternative method of simulation of warhead with different ballistic casing is presented. During simulation the multilayer fragments are replaced by single layer having equivalent mass as it is difficult to model 20000 no of fragments. Hence the results obtained are in good agreement with the available data.

Simulation of Military ground vehicles subjected to buried landmines, and Improvised Explosive Devices (IED) has been carried out by many researchers, and military establishments to understand the effects in detail. But the ability to predict the effects of fragmenting IED’s on military ground vehicles is little known in simulation community. Hydrocode simulation such as Eulerian simulation and Arbitrary Lagrange in Eulerian (ALE) simulation coupled to vehicle structure is widely used methodology to characterize buried detonating IED. But for fragmenting IED’s capturing the fragmentation and fragmenting elements are necessary and ALE may not be able to capture it. There are several statistical and empirical formulations that are available to approximately estimate the number of fragments, but does not provide sufficient information about the velocities of the fragments. In this proposed study, a 152mm High Explosive (HE) OF-540 fragmenting projectile was modelled in detail per geometry and buried 100 mm deep inside the soil. This fragmenting projectile was coupled to U.S. Army’s Ground Vehicle System Center (GVSC) developed generic hull (GH) structure to understand the impact effects of fragmenting fragments. Three different analysis were carried out Projectile buried in soil with adaptive SPH projectile casing, Projectile buried in soil coupled to GH structure with projectile casing as ALE and projectile casing as adaptive SPH methods. Results from all the three analysis were thoroughly analyzed and findings from these analysis is presented in this paper. Solid element formulation is well suited for shock waves, crack propagation and fragmentation problems was used in modeling all the structural and projectile components using commercially available structural code LS-DYNA-3D.

Passive armours are the conventional methods used for protection of AFV against high velocity or high energy projectile threats. But due to improvised penetration capabilities of modern projectiles, these passive armours do not meet the expected safety standards. Hence, alternate counter measure mechanisms need to be developed to enhance the protection level. One of the kill mechanism is deflecting the incoming projectile using blast wave. Directed or controlled blast wave is generated, which creates blast wave in close ranges of the projectile. This blast wave intercepts/deflects the path of the projectile. In this paper, finite element based explicit dynamic analysis is done to analyze the effect of two different kill mechanisms of countermeasure against two different projectile threats. Blast wave effect against long rod penetrator and fragmentation effect against high energy (HE) projectiles are considered in the present paper.

Determination of Surface Danger Zones (SDZs) is a safety related issue of paramount importance which must be addressed. Several technical factors are involved in SDZs determination for a specific weapon and ammunition system: range of fire, dispersion, ricochet and fragmentation. This work is focused on the ricochet and fragmentation of 120 mm typical training round tank ammunition during high velocity impact. The modeling is based on numerical simulation for analyzing the large deformation dynamic response of the round structure during impact. The main aim of the numerical analysis was to examine the various impact parameters of the ricochet i.e. the critical angle for penetration or fragmentation and to understand the effect of the impacted surface properties on the ricochet behavior. The numerical model presented was calibrated and compered to ricochet firing test that included 120 mm tank training round fired against hard armored steel, and soft soil targets.

The fragmentation of rings and shells is a topic of enduring interest both because of the interesting dynamic conditions under which it takes places and the practical importance of fragmentation to various military and industrial applications. Fragmentation is a complex process in which potential fracture sites interact with one another in a deforming body to form a population of fragments. The details of this process are important, and realistic models need to capture the essential features of this process in order to make accurate predictions.

Designers who design structures to mitigate against blast loadings (Remennikov 2007) have another duty and that is to design for the effects of fragmentation not only caused from bulk explosives, but also impact from projectiles. Impact causes damage to a structure and inevitably results in debris from penetration and perforation (breach) of the structural elements. This debris is in fact the result of the damage outcome to a structure either from the blast loading or projectile impact. Fragmentation (Bangash 2006) is the end result of the blast waves impacting the structural elements resulting in scabbing and spall both of which manifest themselves in the production of fragmentation. This fragmentation is propelled outwards at velocity causing supplementary damage to the structure, adjoining structures and individuals caught near the fragmentation. Those designing for fragmentation must consider many parameters from the geometry of the impacted structural element, to the velocity of the fragments, the weight of the fragments and the range of the fragments. As has been said the fragments cause damage and the designers overall duty is to design to mitigate against damage and death or injury to individuals. The pool of worldwide knowledge on this topic is growing exponentially particularly as the need arises with weapons of high velocity and sophisticated projectiles of extreme lethality and range.

The purpose of this article is to develop a mathematical model describing the process of forming the initial kinematic parameters of the fragmentation field. Efforts to increase the effectiveness of ammunitions have been explored, namely increasing the area of damage, by using system for continuous initiation of the explosive substance. The results obtained can be used in the development of ammunitions designed for countering terrorist and other threats as components of critical infrastructure protection systems.

The mid-1960s saw the beginnings of the construction of a Palestinian political field after it collapsed in 1948, when, with the British government’s support of the Zionist movement, which succeeded in establishing the state of Israel, the Palestinian national movement was crushed. This article focuses mainly on the Palestinian political field as it developed in the 1960s and 1970s, the beginnings of its fragmentation in the 1990s, and its almost complete collapse in the first decade of this century. It was developed on a structure characterized by the dominance of a center where the political leadership functioned. The center, however, was established outside historic Palestine. This paper examines the components and dynamics of the relationship between the center and the peripheries, and the causes of the decline of this center and its eventual disappearance, leaving the constituents of the Palestinian people under local political leadership following the collapse of the national representation institutions, that is, the political, organizational, military, cultural institutions and sectorial organizations (women, workers, students, etc.) that made up the PLO and its frameworks. The paper suggests that the decline of the political field as a national field does not mean the disintegration of the cultural field. There are, in fact, indications that the cultural field has a new vitality that deserves much more attention than it is currently assigned.

While over the past century fairly extensive work has been carried out on explosively-driven metallic envelope fragmentation, as the development of explosive materials and warhead configurations continued, the issue under consideration is still topical. The current paper aims to investigate the fragmentation characteristics of explosively-driven steel cylinders when double layer envelopes are used. Mott�s approach was modified in order to account for such particular configuration (layered envelope). Several tests in a simplified type procedure were performed aiming to confirm the theoretical approach.

This paper presents an innovative explosive welding technology, namely Universal Substitutive Explosive Welding technique, which was recently developed by Australian Defence Science and Technology Group to improve the survivability and mobility of military vehicles. The new technique is superior to the existing industrial explosive welding ones in terms of integrity, quality and stability. It is able to significantly upgrade the hardness upper limit of target material and ensure the perfect welding bond between the flyer (soft) and target (hard) panels without size limitation of target panel. Experimental results show that using the new technique raised the ballistic velocity limit (V50) of the explosively welded panel by up to 20% and reduced the bulge depth (related to dynamic plasticity) significantly without any rupture or fragmentation issues. Charpy impact test on the sample fabricated by the new technique showed strong recovery effects with time with no transition temperature. Keywords: Explosive welding, Armour materials, Ballistic velocity limit, Bulge depth, Charpy impact test

Blast-induced fragmentation has a significant influence on the operational efficiency of open pit mines, especially on loading and crushing, the two immediate tasks after blasting. This study presents an empirical method to determine the target fragmentation for efficient loading and crushing at the Aitik mine in Sweden. In the study, the loading efficiency of rope shovels was correlated to the energy consumption and throughput of a gyratory crusher. Two photographic techniques were utilized to assess the feed fragmentation, considering the lithological origin of the ore as an indicator of hardness. The results indicate ore hardness is most influential in mid-range fragmentation, with a marginal effect in coarser fragmentations. The influence of fragmentation is more pronounced in the coarse region, with a sudden reduction in efficiency for P80values coarser than 800 mm. The results suggest tailoring the fragmentation to a P80 of 600-800 mm could lead to higher operational efficiency at Aitik.

Engineering blasting is considered the most economical means of rock fragmentation. The explosive energy utilization is limited to 7% to 22% for fracturing and fragmentation though. The rest of energy components manifests itself into deleterious effects of engineering blasting, namely – noise, air overpressure, ground vibrations, etc. It has been established that proper application of air-decking and stemming plugs may enhance explosive energy utilization to a good extent. This paper substantiates this fact wherein distinct explosive energy utilization enhancement has been achieved with the combination of air-decking and stemming plug. The stemming plug used has acronym as, SPARSH (Stemming Plug Augmenting Resistance to Stemming in Holes) and it is perhaps the only available device which can effectively be used with air-decking. Further, SPARSH doesn’t restrict the type of stemming material and stemming length. This is a significant advancement in the engineering blasting.

The destruction of thick-walled cylindrical shells under explosive loading is a typical example of a problem that cannot be solved without taking into account the heterogeneity of the material’s internal structure. A probabilistic approach to numerical simulation of dynamic fracture is described. Fragmentation spectrum of shells fracture under explosive loading (flat 2D modeling) is compared for different distributions of the strength properties. Using numerical simulation results, it is shown that increasing of strength properties dispersion leads to an increase in the spectrum part of medium and large fragments. It is shown that the fragmentation spectrum is determined mainly by dispersion of the distribution law, but not its shape.

The damage pattern of rear wall/witness plate could express the fragmentation features of projectile relatively, in the ground-based tests of Whipple shield and its improved structure. In this paper, the damages of rear wall for 20 Whipple shield tests are statistically analyzed, and the linkage between the damages with impact conditions (impact velocity and plate-thickness-to-sphere-diameter ratio) are obtained. The damage pattern of rear wall, or the fragmentation pattern of sphere is defined as Intact, Ruptured and Smashed. The perforation hole on rear wall is described quantitatively. The fragmentation patterns under different impact conditions are analyzed based on the propagation and evolution of shock waves. A series of SPH simulations prove and extend the analytical and experimental works, and clearly reveal the normalized relationship between fragmentation pattern and impact condition.

The aim of this work is to simulate the fragmentation of bullets impacted through granular media, in this case, sand. In order to validate the simulation, a group of experiments were conducted with the sand contained in two different box prototypes. The walls of the first box were constructed with fiberglass and the second with plywood. The prototypes were subjected to the impact force of bullets fired 15 m away from the box. After the shots, X-ray photographs were taken to observe the penetration depth. Transient numerical analyses were conducted to simulate these physical phenomena by using the smooth particle hydrodynamics (SPH) module of ANSYS&reg, 2019 AUTODYN software. Advantageously, this module considers the granular media as a group of uniform particles capable of transferring kinetic energy during the elastic collision component of an impact. The experimental results demonstrated a reduction in the maximum bullet kinetic energy of 2750 J to 100 J in 0.8 ms. The numerical results compared with the X-ray photographs showed similar results demonstrating the capability of sand to dissipate kinetic energy and the fragmentation of the bullet caused at the moment of impact.

In medico-legal literature, only a small number of publications deal with lethal injuries caused by shots with modified guns. This might lead to the conclusion that such cases are extremely rare. However, there are cases again and yet again. During the investigation process, the modified gun is of particular importance since it can show an unusual ballistic behaviour. The present paper reports on a suicide of a 60-year-old man, committed with a modified revolver and a lead bullet. The man had a single gunshot wound with entrance at the right temporal bone. Autopsy revealed that the bullet had fragmented into two major parts. The smaller one stood outside the cranial cavity and pushed its way alongside between the cranial bone and scalp to its end position in the left temporal area. The bigger part entered the cranial cavity and ended in the left parietal lobe. In shots on ballistic soap and on a head-model, the ballistics of the weapon and lead bullet were characterized. The angle necessary for bullet fragmentation was determined by shots on ballistic soap and turned out to be 55°-60° at a velocity of around 200 m/s. This knowledge was transferred to contact shots on a head-model consisting of a layered polyurethane sphere filled with 10 % ballistic gelatine and covered with a skin-like cap almost all around. The resulting injury pattern corresponded to the one of the suicide person. The bigger bullet part entered the skull while the smaller part pushed its way alongside between skin and skull causing an outer contour shot. Furthermore, the revolver was documented firing off two bullets by one trigger pull-a phenomenon of importance for forensic casework the authors have not found reported in forensic literature.

The tuneable effects concept is aimed at achieving selectable blast and fragmentation output, to enable one charge to be used in different scenarios requiring different levels of blast and fragmentation lethality. It is a concept QinetiQ has been developing for an energetic fill consisting of three principal components arranged in co-axial layers, two explosive layers separated by a mitigating but reactive layer. The concept was originally designed to operate in two modes, a low output mode which only detonates the central core of high explosive and a high output mode which detonated both the central core and outer layer of the explosive. Two charge case designs where manufactured and tested; one of these designs showed a reduction in blast and fragment velocities of ~33% and ~20%, respectively, in the low output mode.