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The paper introduces the results of numerical simulation of the functioning of shaped charges, whose liners are made of different materials. As a result of their functioning, these charges form high-speed elements. Typically, liners for such charges are produced by the cold stamping technology. An alternative method for producing the liners is metal spinning. Moreover, a spin formed liner is expected to have higher physical and mechanical properties compared to a stamped liner made of the same material and having the same geometrical parameters. To reveal the patterns of molding high-speed elements from stamped and spin formed liners, the action of shaped charges comprised of steel or copper segmental liners of small bending, was simulated numerically using the apparatus of continuum mechanics. The influence of the liner manufacture method was taken into account by varying the values of the physical and mechanical characteristics of the liner material. The design parameters of the simulated charge, with the exception of the liner bending, during the calculation study remained unchanged and corresponded to the parameters of the currently used samples. Following the numerical experiments results, the study shows that the elements molded from spin formed liners are less likely to become fractured while being formed and are also more integral (continuous) in comparison to the elements molded from stamped shaped charge liners.

The paper considers the possibility of using compact projectiles formed by an explosion to break through strong steel barriers of finite thickness protected by a layer of water. There is no problem in penetrating such barriers by high-gradient and high-speed shaped-charge jet of a small diameter formed by shaped charges with ‘high’ conical liners, however, the diameter of the through hole formed in the steel barrier is fairly small and does not meet the defeat criteria for corresponding barriers. To increase the diameter of a through hole in a steel barrier, shaped charges with ‘low’ conical or flat hemispherical liners (in the form of a meniscus) forming compact projectiles can be used, but the movement of such ‘shock cores’ in the water layer is sharply slowed down, up to a complete stop even before interacting with the main steel barrier. The purpose of the paper is to substantiate the possibilities of eliminating this disadvantage when using compact projectiles. Based on theoretical and experimental studies, the paper offers a technical solution related to the known fact of the formation of a cavern (gas cavity) during the movement of a shaped-charge jet in water, expanding as the jet penetrates in the radial direction. In this case, if a known tandem scheme of shaped charges placed one after the other along the axis of the explosive device is used, the first shaped charge, often called pre-charge, will penetrate the body in the head part of the explosive device to the water layer, then form in the latter a cavern up to the main penetrable barrier and the second shaped charge, often referred to as the primary, will form a compact projectile moving to penetrable barrier in the cavity formed by the penetration of shaped-precharge jet in the water. At the same time, due to selecting the necessary delay time between the pre-charge and main charge explosions as well as the design parameters of the pre-charge, the size of the expanding cavity must exceed the size of the compact projectile, excluding its interaction with water up to the approach to the penetrable steel barrier.

We substantiate the recommendations for improving the efficiency of hydro- and hydroabrasive cutting of the honeycomb structures that are widely used in aircraft and rockets, obtained by numerical solving of the spatial dynamic problem with allowance for the physico-mechanical and kinematic parameters of a high-speed jet, the physico-mechanical and structural parameters of the treated honeycomb structure, and the parameters of the technological treatment (feeding and the impact angle of the jet with the face surface of the blanks). A physico-mathematical model and a method of numerical analysis of the process have been developed. The influence of the above parameters on the quality of the surfaces of the treated blanks is illustrated. The results of the calculations are compared with the experimental data.

The study proposes to use charges forming high-speed elongated elements (HSEE) with a variable shape for ground-based simulation of the penetration of particles and elements into the spacecraft's hull. During the operation of such a charge, an explosive throws a metal lining over a distance of several hundred charge diameters. The metal segment lining is deformed during the throwing process and takes the form of an elongated element. In calculations we used steel linings with a degressive and progressive profile whose outer and inner surfaces are formed by spherical surfaces, as well as by a combination of spherical and conical surfaces. The paper shows the results of a numerical analysis which determines the effect of the geometric and physico-mechanical parameters of segmented cumulative linings on the efficiency of the charges forming high-speed elongated elements. The efficiency of the charges was determined by the characteristics of the formed element, i.e. elongation, degree of fullness and the diameter of the horizontal stabilizer. Furthermore, we established the dependences which describe the effect of the lining material dynamic yield point and the radius of transition of the spherical surface to the conical surface on the elongation of the element and the diameter of the horizontal stabilizer. We also showed the possible contradictory effect of changing the radius of transition of the spherical surface of the lining into the conical surface on the aerodynamic stability parameters of the high-speed elongated element.

The article discusses the features of mathematical modeling of technologies using high-speed water jet (for cutting, piercing, cleaning, including their use in the underwater conditions), as well as features of material destruction under water jet treatment. The physical-mathematical model of the process based on the use of the proposed equations of hydroabrasive suspension state and criteria-based dependencies describing the regularities of the processed material destruction was developed on the example of numerical solving two-dimensional axisymmetric problem of piercing holes in the structures of various materials by hydroabrasive waterjet. The features of the solid material destruction during the formation of a through hole in it under the action of a high-speed water jet are shown. Recommendations on choosing kinematic parameters of the cutting jet for different types of waterjet/hydrodynamic machining are given.

We consider the physicomathematical formulation of the problem of explosive formation of a penetrator from a low-sphericity copper lining. Calculations are made for the formation of a penetrator for a phlegmatized hexogen charge for two models of the behavior of the lining material (copper), and the results are compared with the experimental data.