RESEARCH OF POSSIBILITY OF ARMOURING A CABIN OF TYPE Mi-8A HELICOPTER

Given an urgent need to protect a crew of the type Mi-8 helicopter from firearms in the course of combat missions and lack of transparent armor for this type of helicopter in the Armed Forces of Ukraine, it was decided to conduct a theoretical and experimental research with regard to armouring a cabin of type Mi-8 helicopter. The first stage of experimental research was laboratory (bench) research. Samples of bulletproof glass measuring 500x500 mm and 12 and 18 mm thick were provided for testing. The purpose of research bench tests was to determine the degree of protection of the armored glass unit. The samples were fired at with 9 mm pistol bullets, ind. 57-H-181c (Makarov pistol), bullets 7.62 mm pistol cartridge, ind. 57-H-134c (Tokarev pistol) and 5.45 mm bullets, ind. 7H6 (AK-74 assault rifle). The next stage of experimental research was to conduct research ground tests of armored glass of a Mi-8 helicopter crew cabin. The purpose of research ground tests was to evaluate the protective properties of armored glass samples, based on the results of their firing with a single 5.45 mm bullet shots, ind. 7H6 (AK-74 assault rifle) at the shooting range. Samples of armoured glass of the on-board technician and sight (right) glass intended for protection of the flight crew, systems and units of the cabin were presented for ground research tests. The final stage of experimental research was the stage of research flight tests of the Mi-8MSB-B helicopter with 18 mm thick armored glass. The purpose of research flight tests was as follows: to determine changes in the main technical and operational characteristics of Mi-8MSB-B helicopter after installation of 18 mm thick armored glass; to determine the possibility of using 18 mm thick armored glass on Mi-8 helicopters; to assess the effectiveness and safety of armored glass for armouring Mi-8 helicopters’ cabins; to determine peculiarities of using 18 mm thick armored glass on Mi-8 helicopters and peculiarities of Mi-8 helicopter operation with armored glass installed; to obtain initial data for elaboration of tactical and technical (general) requirements for helicopters Mi-8 (particularly concerning the installation of armored glass), approved by Testing Program and Procedure for research flight tests of Mi-8MSB-B helicopter.

STUDY OF THE TRANSPARENT ARMOR STRENGTH UNDER A HIGH-SPEED IMPACT OF A CYLINDRICAL IMPACTOR BY COMPUTER MODELING METHOD

When manufacturing transparent multilayer armor of high threat level, the reinforced silicate glass and transparent ceramics with protecting back films are usually used. The hardness of the front layer of the shield should be much higher than that of the impactor. A promising option isthe use of a single leucosapphire crystal. However, due to its high cost and the impossibility of providing large-sized samples, the transparent polycrystalline materials are developed. One of the most advanced materials is ALON, which is close to leucosapphire in strength characteristics. The aim of this work is to develop a mathematical model to calculate the impact interaction of fragmentation elements with transparent armor. The numerical study is carried out using proprietary software systems. Calculations of the high-speed impact of the steel cylindrical impactor are implemented for three types of shields made of transparent armor. The first two-layer target is made of 20 mm thick tempered glass and a 4 mm thick polycarbonate layer. The second and third targets are three-layered. The front layer of the second target is made of ALON, and the spinel is used for the third one. The second and third layers in these targets are made of tempered glass and polycarbonate, respectively. The calculated results show that ALON is the most impact-resistant material, while spinel is a little less resistant.

TECHNOLOGY OF CREATION OF RADIO TRANSPARENT ARMOR PROTECTION OF RADIO ENGINEERING EQUIPMENT OF VARIOUS PURPOSES FROM FIRE DESTROYING IMPACT

The paper considers the relevance of the work on the creation of radio‑transparent armor protection of radio engineering equipment. A typical design of multi‑layer ceramic armor is considered, the mechanism of interaction of external fire impact and armor protection is disclosed. The complexity of fulfilling the conflicting requirements for ensuring high resistance to fire impact, provided that the necessary radio characteristics are preserved and the mass and size parameters are minimized, is noted. Special engineering solutions have been proposed for meeting the indicated requirements, in particular, the use of compensatory grids in the structure of the material of radio‑transparent armor. A comparison of some ceramic materials and armor steel, using them as the basis of radio transparent armor, is given. The choice of a computing platform with a heterogeneous architecture, which allows the simultaneous use of modules with different architectures in different configurations, during the synthesis of radio‑ transparent armored materials, is substantiated.

Modeling of the interaction of the layered barrier with a high-speed fragment

For the manufacture of transparent armor of high class protection, as a rule, reinforced silicate glasses, as well as transparent ceramics, are used. Since these materials are resiliently brittle, they can be used only in transparent multilayered barriers with protective back films for protection against high-speed fragmentation elements and bullets. Plexiglass or polycarbonate is most often used as the back layer. The barrier’s face layer must have a hardness substantially higher than the hardness of the drummer’s material, and the Hugonievskii elasticity limit must exceed the shock-wave pressure arising at the initial stage in the barrier. The purpose of this paper is to develop a mathematical model that allows, within the framework of a porous elastic-plastic medium with regard to various fracture mechanisms, to calculate the impact interaction of fragmentation elements with transparent armor. Numerical research was conducted with the help of copyright software systems. Experimental studies of the collision of transparent armor with a splinter simulator in the speed range of 1500 ... 2500 m / s were carried out with the use of throwing installations of the NRI AMM TSU.