Parallel Control to Fragments of a Cylindrical Structure Driven by Explosive inside

Abstract

By analyzing the fragmentation distributions of a cylindrical structure and a specific structure, the necessity of parallel control to the fragments is presented. The shell shape of structures has an influence on the fragment spatial distribution. A new design method for the shell shape is proposed. To facilitate the establishment of the numerical model and the machining for relative experiments, the mathematical description of the theoretical calculated generatrix of the shell is simplified. The fragment spraying processes of the designed structures are simulated, and end effects are analyzed. Based on the theoretical design and plentiful simulation data, the relationships between the size of the parallel fragmentation structure and the optimized curvature radius of the shell are expressed by an equation. The equation is validated by numerical means and can be a reliable reference to the design of the parallel fragmentation structure.

Real-time simulation of a fragmenting explosion for cylindrical warheads

“…Chen et al 19 carried out experiments and simulations using the FEA program LS-Dyna, for cylindrical warhead explosions. An example of one of their simulated witness plates is shown in Figure 13.…”

“…The witness plates of the initial impact of fragments on the vehicle are compared with available witness plates from two simulated explosions by Chen et al 19 and Ding et al 20 The witness plates are similar, but the comparison shows the simulation has fewer fragment hits. It is suspected this is because small fragments are not included in the simulation.…”

“…In addition to the above omission, Figure 12 does not include small fragments that are created as the casing expands and the long strings of circumferential fragments are ripped apart from one another. Again, it is unknown if Chen et al 19 and Ding et al 20 include small fragments, but their witness plates suggest they do.…”

Real-time calculation of the initial angle of projection for fragments in cylindrical warheads

“…He assumes the value of the Taylor equation should include the angle the tangent of the casing makes with the horizontal axis. Although Carlucci's approach to calculating an adjustment to the Taylor angle of projection is investigated in this paper, other researchers such as Szmelter and Lee, 38 Tanapornraweek and Kulsirikasem, 17 and Chen et al 39 directly or indirectly, in their equations to calculate fragment angle of projection, also include the tangent the casing makes with the horizontal axis. Figure 7 indicates the shape of an expanding warhead casing for an end-detonated weapon as the casing starts to…”

New Formula for Fragment Velocity in the Aiming Direction of an Asymmetrically Initiated Warhead

“…Given the cost of experiments, correction of the velocity formulas is performed by experimentally verified numerical simulations [14][15][16]. Without loss of generality, three different warheads (different explosive types and casing materials) are modelled and used to calibrate our model.…”