Mitigation of Fragment Spall Induced by Explosive Loading in High Performance Fragment Generators
Mitigation of Fragment Spall Induced by Explosive Loading in High Performance Fragment Generators
Author(s): Kusumkant D. Dhote; Krothapalli P.S. Murthy; Paras N. Verma
No pages: 3
Year: 2014
Article ID: 17-1-2
Keywords: firepower and protection, fragment generator warheads, fragment spall, spall
Format: Electronic (PDF)
Abstract: A typical pre-fragmented warhead uses explosive energy to launch fragments. On initiation of the explosive, detonation waves impinge on the fragments and thereby generate shock waves in the fragment material. As the shock wave reaches the fragment exposed surface, the compressive stress wave is reflected back as a rarefaction wave. At the same time, the rarefaction wave generated from detonation side enters in the fragment. The interaction of these rarefaction waves induces intense tensile stresses resulting in fragment spall. Several researchers have attempted to reduce fragment spall by reducing explosive charge to fragment metal mass ratio (C/M ≤ 0.5) or by altering the explosive initiation location or by provision of shock attenuation material between explosive and fragments or by capping individual fragments. The authors have evolved an innovative solution to mitigate spall by the provision of a composite layer on the fragment exposed surface in the design of high-performance fragment generator (FG) warheads. Its performance is demonstrated experimentally in FG warhead designs having C/M ratios of 1 and 2. The soft recovered fragments in the cone angle of 300 did not show any spall in the case of fragments covered with the composite layer, whereas, the conventional design of (uncovered) fragment did spall.