Assessment of Fragmentation Performance of Blast-enhanced Explosive Fragmentation Munitions.

摘要

A new modeling and experimentation methodology for assessing fragmentation characteristics of blast-enhanced explosive fragmentation munitions had been developed. Fragmentation performance of two high explosive compositions had been examined in this work: a baseline, PBXN-9 (92% HMX, 6% Dioctyl adipate, 2% Hycar 4454) explosive, and an aluminized blast-enhanced PAX- Al composition. The experimental assessment of the fragmentation performance of tested charges was accomplished using the fragmentation arena tests, the sawdust fragment recovery experimentation, and the flash-screen fragment velocity tests. The analytical assessment of the thermodynamic parameters of the PBXN-9 and the PAX-Al compositions was performed employing the JAGUAR code. The analytical assessment of the fragmentation parameters of the explosive fragmentation charges was performed employing the PAFRAG (Picatinny Arsenal Fragmentation) modeling methodology linking the three-dimensional axial symmetric high-strain high-strain-rate hydrocode analyses with a phenomenological fragmentation model based on the Mott's theory of break-up of ideal cylindrical 'ringbombs'. For the PBXN-9 explosive, the PAFRAG modeling has been shown to accurately reproduce the available experimental data, both the fragmentation and the fragment velocity measurements. However, for the PAX- Al explosive, a significant discrepancy between the fragment recovery data and the flash-screen velocity data had been noted and examined. In particular, based on the fragment recovery data, the coupled PAFRAG/thermodynamic analyses indicated that the amount of the aluminum contributing to the momentum of the fragments had to be in the order of approximately 20% of the total available, 80% of the aluminum remaining unreacted. Conversely, from the flash-panel velocity data, the entire 100% aluminum available had to react to agree with the relatively fast fragment time of arrivals measured. The data confidence level of the flash-panel velocity.