Potential Parametric Analysis and Multi-disciplines implementation of Self-forging Devices (Explosively Formed Projectiles & Shaped Charges)

Abstract

The self-forging devices (Shaped Charges and Explosively Formed Projectiles: EFPs) have significant effects on the modern battlefield. In the present sceanerio, these warheads have the key role in fighting against the insurgent forces. The misalignment problems exist in concurrence with the shaped charge jet breaks up and its spewing particles, thus restricts its standoff distance. This makes an EFP to be attractive for large standoff because of its compactness and invariant velocity along the projectile. Even though many researchers have explored different aspects of the self-forging devices but still there remain many issues to be addressed. In this study, we have endeavored to address not only the parametric analysis of the EFPs but also resolved shortcomings of Johnson Cook model, to produce an unrealistically elongated projectile for copper, aluminum and mild steel, by increasing the hardening constant by 10%. The results of the modified Johnson Cook are compared with the semi empirical equations and experimentation which are in fair agreement. The clearance of underwater ammunition (e.g. sea-mines) is a great challenge in the modern era. Underwater simulations and experiments are conducted to highlight the use of the EFPs for safe destruction of sea-mines using Cu liner configuration. Flash x-ray has also been used to record the flight and penetration of the EFP through the target plate. It is difficult to generate a solid, stable and elongated projectile using Tantalum (Ta) as a liner material due to its high ductility and high dynamic property. The multiliner technique has also been developed IV replacing Fe by MS as a stabilization base to the Ta penetrator to improve its performance. The effects of detonation method, confinement and wave-shaper on the multi-liner have also been determined by simulation. The protection techniques (e.g. spaced armour and whipple shields armour) for the main battle tanks (MBTs) have also been developed against self forging devices. The spaced armour being low areal density is used against the shaped charge to analyze the penetration and behind armour effect (BAE). The technique with sub optimum standoff results in slight increase in penetration but reduces the behind armour fragmentation cone angle favouring the safety of the crew in the MBTs. The burster plate thickness is also optimized to ensure less penetration at 2CD standoff and 2CD spacing which is around 2/3 CD. The whipple shields are in use for the protection of a space station and a satellite against the meteoroids and orbital debris. In that configuration, each layer of the shield dissipates part of high speed projectile energy either by breaking the projectile or absorbing its energy. With a modification in the design, this technique is employed against the self-forging devices to protect the light armour such as Infantry Fighting Vehicles. Simulations indicate that the shield thickness of 0.75 mm offers an optimum configuration against the shaped charge as well as the EFP. Experiments also support this evidence. The investigation has demonstrated that weight saving can be achieved by selecting an appropriate combination of whipple shields. The upshot of this research work is the modification and verification of Johnson Cook Model and applications of shaped charges and EFPs in a variety of modes to achieve ibid results.