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Rapid assessment of the spatial distribution of fragments about the D-shaped structure

The deformable warhead is a common type of anti-missile warheads, and the geometric configuration of deformable warhead is close to D shape under the lateral blast loading of auxiliary charge. In this article, the spatial distribution of fragments is taken as the research object, and an empirical model for evaluating the spatial distribution of fragments is expected to be established. First, the empirical model was designed based on dimensional analysis and quadratic interpolation. Then, three different D-shaped structures (D-90°, D-120°, D-150°) were studied by the numerical simulations and experiments. In order to minimize the influence of the axial sparse waves at both ends, only the middlemost layer of fragments was researched. The relationships among d/r, sin α, and sin β were obtained (where d represents the initiation distance, α represents the initial position angle, and β represents the scattering angle). With the scattering angle β and target distance l, the spatial distribution of fragments can be deduced. Based on the fitting formula and the parameters of D-shaped structures, the relationships between d/r, sin α, and sin β of arbitrary D-shaped casing (D-θ) were obtained using quadratic interpolation. Finally, D-105° structure was verified by numerical simulation and empirical formula, both of which coincided well with each other. Therefore, the empirical model can be used to rapidly evaluate the spatial distribution of fragments, especially suitable for the D-shaped structure with a large length–diameter ratio.