Experimental and numerical studies of fragmentation shells filled with advanced HMX-plastic explosive compared to various explosive charges

Abstract

The wide usage of TNT as a main charge for fragmentation shells has been eliminated due to its lower performance and exudation on the fuze thread and relevant safety measures inconvenience. These disadvantages have not become accepted anymore due to the desired safety requirements and the limited efficiency of the TNT, especially when different new explosives are introduced into researches. This research studies the fragmentation calculations of the 120 mm high explosive shell when its is loaded with different explosives rather than TNT. Different explosives have been used in the current research include the melt cast compositions such as Octol and composition B, a cast cured composition based on RDX with HTPB polymer matrix and the plastic explosive composition HMX-silicone. The fingerprint of the fragmentation pattern of each shell loaded with different explosive has been obtained using Autodyn smooth particle hydrodynamic (SPH) algorithm, whose numerical model has been validated with previous measurements using TNT explosive. Based on obtained numerical estimates, the HMX-silicone explosive has been proposed to replace the traditional TNT explosive material. This explosive has been then manufactured and casted into the studied 120 mm shell, where the experimental field pit test was established to collect, separate and analyse the resultant fragments. Current calculations and experimental results showed that the shell loaded by composition HMX-silicone produced the highest fragmentation velocities (i.e. 1.5 times that of TNT) and the largest number of fragments (i.e. 2.7 times that of TNT) with lower masses, which will be recommended for our next production stages instead of the traditional TNT.

Radar Method of Measuring the Velocity of the Fragments

“…The SPH method was used by the researchers [4] to investigate numerically the fragmentation process of a cylindrical metal casing. Another research [5] studied the fragmentation calculations of a 120 mm high explosive shell when it was loaded with an advanced HMX-plastic explosive.…”

The Application of Mott’s Distribution in the Fragmentation of Steel Coaxial Cylinders

“…In the last decades, with the increase in computing power, numerical calculation methods have been imposed as an alternative to the traditional means of study. These methods can produce results that are faithful to reality if the material models are correctly chosen and the discretization of the bodies is appropriate [12][13][14]. However, the predetermined expeditious formulas like Mott's formula do not require a consistent calculation effort nor do they require special computer programming skills by the user, which is why they remain a tool that is still used as a benchmark in design calculations.…”

Research on explosive damage effects of tungsten fiber-reinforced Zr-based bulk metallic glass matrix composite shell

“…Therefore, the quantity, mass, and velocity of the fragments are important indicators that affect the destructive power of the projectile (Zhao et al, 2020). The shell is the source of fragment production, making it the most important component that affects the damage caused by explosive projectiles (Goto et al, 2008). Currently, the most commonly used material for shell is steel (Zhu et al, 2017;Wang et al, 2018;Li et al, 2021;Du et al, 2022a;Elshenawy et al, 2022), but due to different requirements for explosive fragmentation projectiles in different situations, more research is needed to develop shell materials to expand their application range.…”