PENETRATION OF A CUMULATIVE JET OF A PYROTECHNIC DEVICE INTO AN OBSTACLE OF VARIABLE THICKNESS

Pyrotechnic devices based on linear-shaped charges are widely used in rocket and space technology for stage separation and detachment of structural elements. The design of these systems involves a number of complex engineering tasks, one of which is determining the penetration depth of the cumulative jet into an obstacle of variable thickness. This complexity is due to local structural reinforcements in the form of ribs, fittings for operational elements, or deviations resulting from various technological factors. Among these factors are thermal stresses and deformations caused by the welding processes of body sections; deforma- tions due to plastic deformation during the rolling of sheet materials; the cumulative effect of tolerances on the sizes of parts and assembly units; geometric discrepancies in linear shaped charges, such as non-linearity and deviations of the cumulative part from the nominal position. The presence of such inhomogeneities in the rocket separation section complicates the design pro- cess significantlyand requires a detailed analysis of cumulative jet behavior. Existing studies generally provide recommendations for a specific range of distances between the linear-shaped charge and the obstacle, but do not allow for determining the pene- tration depth for a specific cross-section of the structure. Meanwhile, accurate prediction of the penetration depth is critical for ensuring the reliability and safety of rocket and space systems. Thus, the goal is to determine the penetration depth of the cumu- lative jet of a pyrotechnic device into an obstacle of variable thickness in the separation systems of rocket and space technology. Changes in obstacle thickness affect the focal distance and the dependentpenetration depth of the cumulative jet. Research on these parameters was conducted on an obstacle made of aluminum alloy 2219, which is used in the body section of a new design. Existing literature lacks specific data on this obstacle and the type of linear-shaped charges used in Ukraine. To tackle this issue, the primary focus was placed on establishing a functional relationship between the penetration depth of the cumulative jet and the focal distance of the linear-shaped charges’ installation. A calculation for determining the penetration depth of the cumulative jet for any cross-section of a structure with a variable-thickness obstacle is presented. The calculation based on the established relationship allows for predicting the penetration depth of the cumulative jet into an obstacle made of alloy 2219 for an LSC with a diameter of 5 mm, with an error not exceeding 3.96 % (in the range F = 4.1…6.9 mm). These materials may be useful for engineering and technical personnel in the development and optimization of pyrotechnic systems in rocket and space technology.