Influence of Geometric Features of the Peripheral Part of the Thin-Walled Spherical Segment on the Explosive Throwing Process

Abstract

The main factors controlling the formation of the stern of explosively formed projectiles are investigated using numerical calculations in a three-dimensional formulation of a problem. To form folds in the stern, it is proposed to use thin-walled spherical segments with a peripheral thickness deviation in terms of decreasing or increasing with respect to the thickness in the central part. The configurations of explosively formed projectiles with inclined folds in the stern are shown, and it is proposed to describe the fold inclination by two angles of its position. The effect of folds in the stern on the change in aerodynamic coefficients for a wide range of angle of attack is numerically studied. The angular velocity of the axial rotation of explosively formed projectiles with inclined folds in the stern is estimated based on the Newton method and considering the angles of its position. The results obtained are of interest to specialists working in the field of physics of explosion and high-speed impact, as well as those dealing with aerodynamics of aircrafts, mainly of axisymmetric shape

Formation of an Explosively Formed Penetrator Warhead Using a Step-Shaped Charge

“…Li et al [12] investigated the feasibility of polygonal charge shell layers to form EFP with large aspect ratio and found that hexagonal polygonal charges can form EFP structures with better aerodynamic performance. Baburin et al [13] developed a model for forming a tilted-fold tail EFP, studied the influence of the tail on the change in the aerodynamic coefficients for a wide range of head-on angles, and calculated the angular velocity of the axial rotation of the tilted-fold tail EFP based on Newton's method. Ding et al [14] used stress-wave theory to analyze the long-rod fracture mechanism of explosively formed projectiles in the forming stage and experimentally verified the critical velocities of copper and tantalum foil forming.…”