Maximum fragment velocity of hollow charges with different aspect ratios

Fragment velocity is an important indicator of warhead damage power. The maximum fragment velocity varies with the charge aspect ratios. Existing formulae for the maximum velocity have limits and do not apply to hollow charges. In this work, numerical models based on experimental results were conducted on hollow charges with various aspect ratios. Under the different hollow diameters, the changing rules of the maximum fragment velocity along with the aspect ratios are consistent with each other. The differences between the driving behaviors under different detonations were also discovered. A new formula applicable to hollow charges for the maximum fragment velocity under end detonations was established. Furthermore, a formula for the maximum fragment velocity under the central line or hollow surface detonations was obtained for the first time. The accuracies of the established formulae were verified against the experiments. This study can provide valuable references for the optimal design and damage assessment of ammunition, and also for the design of protection structures.