Анотація В роботі представлені результати досліджень зі встановлення параметрів просторово-масового розподілу металевих дисків природного подрібнення, що входять до складу осколково-пучкового снаряда. Дослідження проводились із застосуванням чисельного методу комп'ютерного моделювання динамічних нестаціонарних процесів в континуальній постановці за допомогою програми LS-DYNA.

This paper describes the process of shooting a mobile armored combat vehicle with directed fragmentation-beam shells as a discrete-continuous random process. Based on this approach, a stochastic model has been proposed in the form of a system of Kolmogorov-Chapman differential equations. A universal model of the process of defeating a moving armored target with directed fragmentation-beam shells has been built, which would provide preconditions for experimental studies into the effectiveness of various variants of the components of the artillery system for three-shot firing. The execution of an artillery task is considered as a set of certain procedures characterized by the average value of its duration. They are dependent on the firing phases involving a prospective automatic gun and the explosive destruction of fragmentation-beam shells while the explosive destruction of each shell case is characterized by the self-propagation of the reaction of explosive transformations based on tabular data on the target. An indicator of the functionality of various design options for fragmentation-beam shells is the probability of causing damage by «useful fragments» in the vulnerable compartments of a combat armored vehicle. Devising universal models for the process of shooting a moving armored vehicle forms preconditions for further full-time experiments in accordance with the design solutions defined as a result of modeling. It is possible to use the developed discrete-continuous stochastic model in other modeling tasks to determine the optimal value of defeat. As regards the practical application of discrete-continuous stochastic models, one can argue about the possibility of reducing the cost of performing design tasks related to weapons by 25 % and decreasing the likelihood of making mistakes at the stage of system engineering design

Results of studies of the explosive expansion of a set of shrapnel discs of natural crushing are described in the article. Set consisted of two disks of different thickness, but of a fixed total mass. The studies were carried out by computer simulation of shock-wave processes in a continuous formulation using the ANSYS/LS-DYNA program. The program of computer design foresees development of three-dimensional certainly-element model including, in accordance with symmetry of the examined system fourth part of the examined explosive system of casting block, with imposed on its knots of the proper scopes terms concerted with taken mixed Lagrangian-Eulerian approach within the framework of the continuum model. The effect of the order of installing disks of different thickness on the distribution of their mass and its velocity in the middle of the meridional angle of expansion is established. The analysis of the computer simulation presented on the basis of numerical studies on the distribution of the mass of the disks and its velocity of motion suggests that to create a narrow high-speed uniformly filled fragmentary mass of the axial flow, it is necessary to change the geometric shape of the disc so that in the central angular zones of the disks. This allows the velocity of the fragment mass to be aligned along the radius of the discs and to fill the first angular zones with the required mass of fragments.

The development of industry stimulates the development of modern approaches to the optimization of welded structures. The use of pulsed electromagnetic fields, plasma currents, electrodynamic forces and their combined effects is a new trend in engineering practice to improve the mechanical characteristics of metal materials and welded joints (WJ). Treatment with a pulsed electromagnetic field (TwPEMF) is a promising direction for optimizing the stress-strain states (SSS) of welded structures made of non-ferromagnetic metal materials. Using the method of electronic speckle interferometry, the effect of TwPEMF on the SSS of specimens of circumferential WJ with a thickness of δ = 1.0 mm from aluminium AMg6 alloy was investigated. Based on the original procedure using an accelerometer, the kinetics of the action of the force P of the magnetic field pressure on the residual displacements f and SSS of the specimens during their TwPEMF were investigated. TwPEMF of WJ specimens was performed without and with the use of an additional shield made of AMg6 alloy δ = 5.0 mm. It was found that the use of a shield increases the amplitude values of force P by up to two times, which is caused by an increase in the active volume of the conductive medium. At the same time, TwPEMF without and with the use of a shield contributes to the reduction of f values by 2 and 4 times, respectively, and residual SSS by 50 and 80%. On the basis of mathematical modelling, the advantages of using electrodynamic treatment (EDT) of butt WJ δ = 3.0 mm of АMg61 (1561) alloy in the TIG welding process compared to EDT at room temperature (Tk) are substantiated. According to the results of the model verification, it was proved that EDT during TIG contributes to the formation of peak values of residual compressive stresses in the weld zone by 60% more than EDT during Tk. The use of a pulsed barrier discharge (PBD), which generates a low-temperature plasma on the surface of the metal being treated, contributes to the optimization of its structure. An increase in the hardness HV of structural 25KhGNMT steel as a result of its PBD treatment from 420 to 510 units was established, which is accompanied by the dispersion of the metal microstructure.