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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.