RU2531705C2 - Fabric armour vest with antishock device - Google Patents

Abstract

FIELD: weapons and ammunition.

SUBSTANCE: invention proposes a fabric armour vest containing chest and back sections, in the covers of which there located are protective screens (fabric packs) from high-strength aramid fabric (TSVM or equivalent), and on their inner surfaces there located is an antishock device including a shock absorber and a base material. The shock absorber provides for removal of a fabric pack of the armour vest from the base material to implement deflection of a fabric pack during incorporation of a damage agent into it. The base material is made in the form of shock compensators of sections representing chambers from air-tight rubber-coated aramid fabric with elastic filler inside it, which are lined on both sides with packs of plates; besides, the back pack of plates is bonded to shock compensators so that centres of masses of its square elements can be located opposite angular points of connected shock compensators. Packs of plates represent assemblies of fabric layers of the same base as the primary protection of the armour vest (TSVM or equivalent), which are bonded to each other to ensure stiffness, except for a bending zone. Sizes of plates of the pack in the form of squares are chosen based on equality to maximum specific size of the base of cavern of a temporary cavity formed in soft tissues of a biological object at non-penetration of the fabric armour vest. In each shock compensator there is one or more tightly closed holes with a total surface area referring to front area of the shock compensator of not more than 1:8, which provide for air efflux from the shock compensator at constant pressure, at which holes are opened due to action of the pack plates involved in movement through the primary protection of the armour vest.

EFFECT: reduction of degree of a damaging action of damage agent on a biological object at non-penetration of an armour vest without any increase of its weight.

5 dwg, 4 tbl

Description

The invention relates to personal protective equipment of personnel, in particular to armored or bulletproof clothing, and can be used in military affairs and in special units of independent power structures and departments.

Known fabric bulletproof vests (BZ), the basis of which are protective elements made in the form of a chest and back, which are attached to the body using shoulder and waist belts or using a special cover with front (on the chest) and back (on the back) pockets, where protective elements (armor panels) are inserted [1]. Some BZ models are supplied with additional elements designed to protect the inguinal region and upper shoulder girdle, which form the so-called peripheral protection.

All fabric BZ are made exclusively from a protective structure on a fabric basis. The design of the tissue BZ consists of several layers of aramid fabric, structurally assembled into a single protective screen (armored panel). The number of layers in the armored panel can range from 20 to 30 or more, which is determined by the creation of the required level of protection. Certain problems with the use of tissue BZ are associated with a decrease in the armor effect during non-penetration. For this purpose, additional damping materials are used in the form of packages or plates placed on the inside of the BZ adjacent directly to the body of the military man.

As of today, the Russian Armed Forces are on the supply of fabric BZ of two generations: the 90s. (BZ 6B11 series) and modern - BZ 6B23 series.

Of the current full-time BZ, it is possible to distinguish 6B23 anti-fragmentation, the full name of which is: general-purpose II level bulletproof vest 6B23 anti-fragmentation.

The material of the armor panels of the chest and dorsal sections of the bulletproof vest 6B23 are fabric packages [2].

The specified body armor is the prototype of the proposed one and has the following main drawback, which consists in the occurrence of residual changes in the body of a serviceman in case of non-penetration of the BZ that can lead to further death. The traumatic effect for rigid BZ was eliminated by installing shock absorbers made of foamed polymeric material behind the metal armor, comparable in thickness to the height of the rear bulge of the protective plate from the bullet. In developed in the early 80's. Army BZ series 6B4 based on ceramic armored materials were used semi-flexible shields of glued fabric layers and polyurethane foam. This achieved not only the suppression of the impact, but also its distribution over a large area. Subsequently, a device of a similar purpose abroad was called anti-shock panels.

However, the subsequent emergence of individual means of armor protection from fabrics based on high-strength synthetic fibers of the so-called “soft armor” to the maximum exacerbated the seemingly completely resolved problem of armored contusion injury in case of non-penetration of the BZ. "Soft armor" in some cases, allowing to significantly reduce the mass of the BZ, was unacceptable due to unacceptably high traumatic effects on the soft tissues of the biological object (BO) in case of non-penetration of the BZ. Unlike hard armored elements, “soft armor” has practically no resistance to energy impact in the direction of the bullet’s impact and, therefore, does not distribute the impact energy of the striking element (PE) communicated to it over a large area. The main part of the impact energy is concentrated within the boundaries of the contact of PE with the BZ and is transmitted to the body. Experience has shown that for "soft armor" the methods of extinguishing the dynamic effects described above are unacceptable, and increasing its stiffness, for example, through stitching, gluing, etc., as a rule, reduces its bulletproof resistance.

Closest to the claimed body armor is a fabric body armor with an anti-shock device according to the application of 11/27/2007 (Pat. RF No. 2395055) [3].

The technical result is expressed in a significant reduction in the degree of damaging effect of PE on a biological object through a BZ tissue package in case of non-penetration.

The specified technical result is achieved due to the fact that on the inner side of the fabric package BZ 1 is placed an anti-shock device (figure 1), consisting of a shock absorber 2 made of foam rubber, and a substrate 3 (figure 2). The substrate 3 is made in the form of shock-compensating sections 4, which are chambers made of rubberized TSBM fabric with foam rubber 5 inside and lined with packs of plates 6. The back pack of plates 6 is glued to shock compensators 4 so that the centers of mass of its square elements are located opposite the corner points of articulated shock compensators 4.

Figure 1 shows a structural diagram of a fabric body armor with anti-shock device; figure 2 is a section along aa in figure 1; figure 3, 4 is a design diagram of the process of interaction of the striking element with a fabric package of body armor; figure 5 - diagram of the process of interaction of elements of the system "Damaging element - tissue package body armor - a biological object."

, где $$z_{{к}_{л}}$$

- конечное перемещение лицевой поверхности тканевого пакета БЖ в точке попадания в него ПЭ за время проникания ПЭ в тканевый пакет БЖ в направлении, нормальном к БО. По данным расчета (см. табл.3) толщина амортизатора 2 для существующих БЖ должна быть больше $$z_{{к}_{л}}$$

на величину его предельного сжатия (20% от толщины поролона) и должна составлять не менее 1,1 толщины тканевого пакета БЖ 1, т.е. в_ам=1,1 в_ТП.The shock absorber 2 (figure 2) does not play any protective role, but ensures the removal of the BZ 1 tissue bag from the substrate 3 in order to realize the deflection of the BZ 1 tissue bag during the introduction of PE into it, thereby contributing to the absorption of its kinetic energy. Its thickness is chosen from the condition $${\mathrm{at}}_{\mathrm{but}m}>z_{{\mathrm{to}}_l}$$

where $$z_{{\mathrm{to}}_l}$$

- the final movement of the front surface of the BZ tissue package at the point where PE enters into it during the penetration of PE into the BZ tissue package in the direction normal to BO. According to the calculation (see table 3), the thickness of the shock absorber 2 for existing BZ should be greater $$z_{{\mathrm{to}}_l}$$

by the value of its maximum compression (20% of the thickness of the foam rubber) and should be at least 1.1 the thickness of the fabric package BZ 1, i.e. in _am = 1.1 in _TP .

Package 6 (figure 2) is an assembly of several layers of fabric of the same base as the main protection of the BZ (aramid fabric TSVM) glued together to provide stiffness, with the exception of the fold zone of the same fabric, which provides flexibility of the package of layers with the gap l (see figure 1) between them in half of the arc when bending by 90 °, which is l = 1.88 mm The dimensions of the package 6 (b) in the form of squares (see Fig. 1) are selected from the condition - not less than the maximum characteristic size of the base of the cavity of the temporary cavity (L or d _in ) formed in the soft tissues of the BO during non-penetration of the tissue BZ, which according to experimental and theoretical studies with the non-penetration of modern tissue BZ is = 100 mm (see tables 1, 2). The increase in the size of the square cell of the package 6 (Fig.1, 2) and the size of the shock absorber 4 leads to a decrease in the flexibility of the BZ.

Each shock absorber 4 has one or more hermetically sealed openings that allow air to flow out of shock absorber 4 (throttling) while maintaining a constant air pressure inside it, i.e. P ₂ = const, in which holes are opened or opened from the action of the striking element on the BZ tissue package.

Since the temperature regime of operation of the BZ provides for the interval -50 ... + 50 ° C, the air pressure in the shock absorber 4 (figure 2) at a temperature of -50 ° C should correspond to normal (P ₀ = 1 · 10 ⁵ Pa). Since the shock absorber 4 is closed hermetically, the air pressure in it will depend on the ambient temperature and will be no less than atmospheric, i.e. P ₁ ≥P ₀ . When immersed in water in the BZ, ceteris paribus, the additional buoyancy force (Archimedean force) will be F _nd = (2 in _PP + in _ku ) S _З ρ _in g, where in _PP , in _ku are the thickness of the plate pack and shock absorber, respectively; S _s - the area of protection of the BZ (surface area of the substrate); ρ _in is the density of water; g is the acceleration of gravity.

The principle of operation of the BZ with an anti-shock device while providing protective properties is as follows.

When PE enters the BZ fabric package 1 (Figs. 1, 2), the latter is involved in movement and, as the cavity develops, together with the damaging element, acts on at least one packet 6 (see Fig. 2), which is located in front of shock compensators 4.

Involved in the movement of the package 6 acts on the shock absorber 4, adiabatically compressing the air in it up to a certain pressure Р ₂ , at which one or more throttling openings or openings that ensure the outflow of air from the shock absorber 4 while keeping the air pressure inside the shock compensator constant and equal to P ₂ up to its maximum flow rate with complete braking of the acting elements (PE, fabric bag BZ 1 and package 6 of the substrate). The air pressure in the shock absorber P ₂ and the diameter or area of the throttling one or more holes are determined by the appropriate thermodynamic calculation.

To assess the technical result, we first determine the parameters of the interaction of PE with BO in a standard tissue BZ, provided it is not broken.

The process of interaction of the elements of the system “PE - tissue BZ - BO” is conditionally divided into two stages: - the first is the stage of involving the tissue bag in the movement in the zone of PE exposure to it. This interaction stage ends with a point in time when the velocities of PE and BZ tissue packet in the impact zone become equal, i.e. the penetration rate of PE into the fabric bag will be zero. At this stage, the strength of resistance of soft tissues of BO can not be taken into account due to its smallness compared with the strength of the resistance of the tissue package BZ to the introduction of PE; - the second is the stage of inhibition by the soft tissues of the BO tissue package of the BZ and PE, which move together.

This problem relates to the theory of the impact of PE on a moving barrier acting on an elastic incompressible medium, and was solved under the following assumptions:

- PE 7 (Figs. 3, 4) interacts normally with the BZ 1 tissue bag and is not deformed during implementation (where in Figs. 3, 4 0 ₁ x ₁ y ₁ z ₁ and 0xyz are the inertial and non-inertial reference systems, respectively);

- all the energy of the PE is spent on overcoming the resistance force of the BZ tissue package and on drawing it into motion;

- precession and nutation of PE are absent;

- the rate of introduction of PE into the BZ tissue package (V _in ) is small (V _in = V _e -V _TP , where V _e is the speed of movement of PE, V _TP is the speed of movement of the BZ tissue package in the area of PE contact with it), therefore, we can assume that only the strength component of the resistance force of the tissue bag acts on PE, the value of which is assumed constant;

- during the penetration of PE into the BZ tissue package, soft BO tissues practically do not resist the formation of bulged BZ tissue packet in the direction of PE movement;

- the development of deformation of the BZ tissue package occurs in the form of a spherical surface from the center of impact of PE into it;

- the thickness of the tissue bag BZ does not change during its indentation into the soft tissues of BO, because tensile elongation of tissue fibers of domestic and foreign production does not exceed 5%;

- pressure in the soft tissues of BO is determined only by the dynamic effect on them.

Using the equation of motion of PE when introduced into the BZ tissue bag, we determine the resistance strength of the BZ tissue bag to PE penetration provided that it is located on a rigid base

$$F=m_{\mathrm{uh}}\frac{V_{P\mathrm{FROM}{N}_{\mathrm{well}}}^2}{2{\mathrm{at}}_{TP}},(\mathrm{one})$$

where m _e is the mass of PE;

V _PSNzh - the ultimate rate of non-penetration of the BZ tissue package provided that it is located on a rigid base;

in _TP - the thickness of the fabric bag BZ.

The limiting rate of non-penetration of the BZ tissue package provided that it is located on a rigid base (V _PSNzh ) is determined experimentally or calculated through a specific unit impulse [4].

We define the interaction parameters of the elements of the system “PE - BZ tissue package” for the conditions of the free position of the fabric package (the first stage of solving the problem).

To do this, we use the system of equations:

- the equation of motion of PE in a non-inertial reference frame along the OZ axis (see figure 3):

$$m_{\mathrm{uh}}=\frac{d{V}_{\mathrm{at}}}{dt}=-F-m_{\mathrm{uh}}\frac{d{V}_{TP}}{dt},(2)$$

where V _TP is the speed of movement of the BZ tissue package at the point of impact of PE on it in the direction of its action;

- the equation of motion of the BZ tissue package at the point where PE hits it in the direction of the OZ axis:

$$m_{TP}\frac{d{V}_{TP}}{dt}=F,(3)$$

where m _TP is the mass of the BZ tissue package involved in the movement.

The mass of the BZ tissue package involved in the PE movement varies with time and provided that the speeds of its deformed part in the radial directions from the point of impact are equal, it can be determined as for a spherical surface formed from the volume of the BZ tissue package covered by a deformation of mass equal to

$$m_{TP}=\pi {\mathrm{<figure-callout\; id="2"\; label="z\; l"\; filenames="00000122.png"\; state="\{\{state\}\}">z\; </figure-callout>}}_l^{}{\mathrm{at}}_{TP}{\rho }_{TP}(\mathrm{four})$$

where z_l - coordinate of movement of the front surface of the BZ fabric package along the OZ axis at the point of impact of PE or the radius of the deformed surface BZ;

ρ _TP is the density of the material of the BZ tissue package.

Solving equations (2), (3) together, it is possible to determine the limiting rate of non-penetration of the BZ tissue package with its free position in space

$$V_{P\mathrm{FROM}{N}_{\mathrm{from}\mathrm{at}}}=V_{P\mathrm{FROM}{N}_{\mathrm{well}}}\sqrt{\mathrm{one}+\frac{m_{\mathrm{uh}}}{m_{T{P}_{\mathrm{to}}}}},(5)$$

;Where $$m_{T{P}_{\mathrm{to}}}=\pi z_{{\mathrm{to}}_{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="00000122.png"\; state="\{\{state\}\}">l</figure-callout>}}}^2{\mathrm{at}}_{TP}{\rho }_{TP}$$

;

- конечное перемещение лицевой поверхности тканевого пакета БЖ в точке попадания в него ПЭ за время проникания ПЭ в тканевый пакет БЖ в направлении оси OZ. $$z_{{\mathrm{to}}_l}$$

- the final movement of the front surface of the BZ tissue package at the point where PE enters it during the penetration of PE into the BZ tissue package in the direction of the OZ axis.

An analysis of expression (5) shows that the limiting rate of non-penetration of the BZ packet in the free state is greater than when placed on a rigid base and the greater, the lighter the material of the BZ tissue package and the less its mass involved in the movement.

Let us evaluate the motion parameters of the BZ tissue package provided that it does not penetrate PE.

First, we determine the time corresponding to the moment of termination of the introduction of PE in the BZ tissue package (t _to ) (V _in = 0, V _e = V _TP ).

Substituting equation (3) into (2), separating the variables and integrating the expression, we obtain

$$t_{\mathrm{to}}=\frac{2{\mathrm{at}}_{TP}{V}_{\mathrm{from}}}{V_{P\mathrm{FROM}{N}_{\mathrm{from}\mathrm{at}}}^2}.(6)$$

where V _with - the speed of meeting PE with a tissue bag BZ.

The motion parameters of the BZ tissue package for time t (the time of introduction of PE into the BZ tissue package) can be determined using equations (1), (3), (6). The speed of the tissue bag in the impact zone of PE will be equal to

$$V_{T{P}_{\mathrm{to}}}=\frac{m_{\mathrm{uh}}{V}_{\mathrm{from}}}{m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}}}.(7)$$

. Для этого воспользуемся уравнением (3)Find the displacement (deflection) of the front surface of the BZ tissue package at the point of impact of PE on it over time $$t_{\mathrm{to}}{\text{(Z}}_{{\text{to}}_{\text{l}}}\text{)}$$

. To do this, we use equation (3)

$$m_{TP}\frac{d{V}_{TP}}{dz}\cdot \frac{dz}{dt}=F,$$

Where $$\frac{dz}{dt}=V_{TP}.$$

Separating the variables and integrating this equation, we obtain

$$z_{{\mathrm{to}}_l}=\frac{m_{T{P}_{\mathrm{to}}}{V}_{T{P}_{\mathrm{to}}}^2}{2F}.(8)$$

Substituting expressions (1), (7) into equation (8), we obtain

$$z_{{\mathrm{to}}_l}=\frac{m_{\mathrm{uh}}{V}_{\mathrm{from}}^2{\mathrm{at}}_{TP}}{(m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}})V_{P\mathrm{FROM}{N}_{\mathrm{from}\mathrm{at}}}^2},(9)$$

.Where $$m_{T{P}_{\mathrm{to}}}=\pi z_{{\mathrm{to}}_{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="00000122.png"\; state="\{\{state\}\}">l</figure-callout>}}}^2{\mathrm{at}}_{TP}{\rho }_{TP}$$

.

.The maximum movement of the front surface of the BZ tissue package during the introduction of PE into it will correspond to the speed $$V_{\mathrm{from}}=V_{P\mathrm{FROM}{N}_{\mathrm{from}\mathrm{at}}}$$

.

Equation (9) can be converted to the form:

$$z_{{\mathrm{to}}_{\mathrm{<figure-callout\; id="3"\; label="l"\; filenames="00000122.png"\; state="\{\{state\}\}">l</figure-callout>}}}^3+p{z}_{{\mathrm{to}}_l}+q=0(10)$$

;Where $$p=\frac{m_{\mathrm{uh}}}{\pi {\mathrm{at}}_{TP}{\rho }_{TP}};$$

;

$$q=-\frac{m{V}_{\mathrm{from}}^2}{\pi {\rho }_{TP}{V}_{P\mathrm{FROM}{N}_{\mathrm{from}\mathrm{at}}}^2}$$

Equation (10) is cubic. The solution of this equation is carried out using the Cardano formula.

Then the coordinate when moving the back surface of the BZ tissue package at the point of impact of PE, subject to assumption seven, will be equal to

$$z_{{\mathrm{to}}_T}\approx z_{{\mathrm{to}}_l}+{\mathrm{at}}_{TP}.(\mathrm{eleven})$$

To assess the degree of damage to a biological object in tissue BZ, we consider the second stage of interaction of the elements of the “PE - BZ-BO tissue package” system — this is the stage of inhibition of PE and the BZ soft tissues involved in the movement of the BZ tissue package.

The solution to the problem was carried out under the following assumptions:

- of the components of the resistance force of soft tissues of BO, only inertia is taken into account;

- energy losses during the interaction of the elements of the system “PE - fabric package BZH-BO” on friction and heating are neglected.

A diagram of the process of interaction of the elements of the system "PE - fabric package BZH-BO" is presented in figure 5.

The equation of motion of the fabric pack BZ 1 with PE 7 when braking with soft tissues BO 8 has the form:

$$(m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}})\frac{d{V}_{TP}}{dt}=-P(z)S_{TP}^{te\mathrm{to}},(12)$$

- давление в мягких тканях БО при воздействии на него ПЭ и тканевого пакета БЖ (см. фиг.5);Where $$R(z)=\frac{{\rho }_{MT}{\mathrm{<figure-callout\; id="2"\; label="V\; T\; P"\; filenames="00000122.png"\; state="\{\{state\}\}">V\; </figure-callout>}}_{TP}^{}}{2}$$

- pressure in the soft tissues of BO when exposed to PE and a tissue bag of BZ (see figure 5);

ρ _MT is the density of soft tissues of BO;

- текущая площадь контакта тканевого пакета БЖ с мягкими тканями БО в проекции на плоскость, нормальную к оси OZ; $$S_{TP}^{te\mathrm{to}}=\pi {\mathrm{but}}^2$$

- the current contact area of the BZ tissue package with the soft tissues of the BO in projection onto a plane normal to the OZ axis;

and - the current value of the magnitude of the chord bulging tissue package BZ in the form of a spherical segment (see figure 5).

We find the maximum cavity depth in soft tissues when braking the mobile system "PE - BZ tissue package". To do this, we use equation (12), which can be converted to the form

$$(m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}})V_{TP}\frac{d{V}_{TP}}{dz}=-\frac{{\rho }_{MT}{\mathrm{<figure-callout\; id="2"\; label="V\; T\; P"\; filenames="00000122.png"\; state="\{\{state\}\}">V\; </figure-callout>}}_{TP}^{}}{2}\cdot \pi (z^2-{\mathrm{at}}_{TP}^2).(13)$$

Separating the variables and integrating expression (13), we obtain

$$2(m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}})\ln V_{T{P}_{\mathrm{TO}}}\cong \pi {\rho }_{MT}(\frac{z_{\mathrm{ABOUT}{\mathrm{TO}}_{\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="00000122.png"\; state="\{\{state\}\}">T</figure-callout>}}}^3}{3}-{\mathrm{at}}_{TP}^2{z}_{\mathrm{ABOUT}{\mathrm{TO}}_T}),(\mathrm{fourteen})$$

- окончательное перемещение (прогиб) тыльной поверхности тканевого пакета БЖ в точке удара по нему ПЭ.Where $$z_{\mathrm{ABOUT}{\mathrm{TO}}_T}$$

- the final movement (deflection) of the back surface of the BZ tissue package at the point of impact of PE on it.

Equation (14) can be converted to the form:

$$z_{\mathrm{ABOUT}{\mathrm{TO}}_{\mathrm{<figure-callout\; id="3"\; label="T"\; filenames="00000122.png"\; state="\{\{state\}\}">T</figure-callout>}}}^3+p{z}_{\mathrm{ABOUT}{\mathrm{TO}}_T}+q=0(\mathrm{fifteen})$$

;Where $$p=-3{\mathrm{at}}_{\mathrm{<figure-callout\; id="2"\; label="T\; P"\; filenames="00000122.png"\; state="\{\{state\}\}">T\; </figure-callout>}P}^2$$

;

$$q=-\frac{6(m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}})\ln V_{T{P}_{\mathrm{TO}}}}{\pi {\rho }_{MT}}$$

The solution of this cubic equation (15) is also carried out using the Cardano formula.

The diameter of the bulged BZ tissue package on its back surface at the moment of stopping it with soft tissues of the BO or the entrance diameter of the cavity in them will be equal to

$$d_{\mathrm{at}x}=2\mathrm{but}=2\sqrt{z_{\mathrm{ABOUT}{\mathrm{TO}}_T}^2-{\mathrm{at}}_{\mathrm{<figure-callout\; id="2"\; label="T\; P"\; filenames="00000122.png"\; state="\{\{state\}\}">T\; </figure-callout>}P}^2}.(16)$$

According to assumption seven, the height of the bulged back surface of the BZ tissue package or the depth of the cavity in the soft tissues of the BO (see figure 5) will be equal to

$$h=z_{\mathrm{ABOUT}{\mathrm{TO}}_T}-{\mathrm{at}}_{TP}.(17)$$

Finally, the volume of the cavity in the soft tissues of BO, formed when they are inhibited by PE and BZ tissue package, will be equal to

$$W=\frac{\mathrm{one}}{6}\pi h(3a^2+h^2)=\frac{\mathrm{one}}{3}\pi (z_{\mathrm{ABOUT}{\mathrm{TO}}_T}-{\mathrm{at}}_{TP})(2z_{\mathrm{ABOUT}{\mathrm{TO}}_T}^2-z_{\mathrm{ABOUT}{\mathrm{TO}}_T}{\mathrm{at}}_{TP}-{\mathrm{at}}_{TP}^2).(\mathrm{eighteen})$$

Through the parameters of the cavity in the soft tissues of BO, the degree of concussion (SC) of BO can be determined.

The dimensions of the temporary cavity are determined by the following characteristics: depth (H or h), base (L or d _in ), area (S) and volume (W). In the experimental-theoretical method of determination, the first three parameters are easily set directly from the X-ray diffraction pattern, and the last - the volume is the calculated value, defined as the volume of the ellipsoid of revolution according to the following formula [1].

$$W=\frac{S^2}{H}.(19)$$

The significance of all the listed parameters of the temporary cavity from the magnitude of the bullet energy for tissue BZ is presented in Tables 1, 2.

Table 1 Characterization of the parameters of the temporary cavity (VP) depending on the magnitude of the energy properties of the striking element (BZ 6B5.001) [1] The speed of the meeting of the bullet with the BZ, V _s , m / s Striking element Bullet weight, g Kinetic energy of a bullet, J VP Settings Degree of damage (concussion), SC H cm L cm S cm ² W cm ³ 300 268.8 4.6 10.0 37.7 309.0 2.87 Bullet PM 9 mm 5.95 280 230,0 4.4 10.0 34.0 262.7 2.71 266 210.9 4.0 9.7 31.9 254.4 2.43 Bullet M1911A1 11.43 mm 15,20 240 436.5 4.9 9.5 37.5 287 3.07

The results of the analysis of experimental and calculated data indicate that the parameters of the temporary cavity are largely determined by the kinetic energy of the bullet. As it turned out, the dimensions of its base fluctuate slightly with a change in the energy of the bullet [1]. Subsequently, an empirical relationship was obtained that relates the severity of contusion damage (SC) to the depth (H) and area (S) of the temporary cavity (VP) [1].

$$\mathrm{FROM}\mathrm{TO}=-0.409+0.709H+0002S.(\mathrm{twenty})$$

table 2 The calculated values of the parameters of the temporary cavity and the degree of damage (contusion) depending on the energy of PE (BZ 6B5.001) The speed of the meeting of the bullet with the BZ, V _c , m / s VP Settings Relative error in determining SC, δ _SC ,% Striking element Bullet weight, g SC _exp / 1 / SC _theory The probability of contusion lesion, R _KP h cm d _inx W cm ³ 300 3,59 8.25 120.3 2.85 2.68 5.96 0.61 Bullet PM 9 mm 5.95 280 3,55 8.17 116.6 2.71 2.66 1.85 0.60 266 3.52 8.12 114.1 2.43 2.65 9.05 0.59 Bullet M1911A1 11.43 mm 15,20 240 4.91 10.90 290.9 3.07 3.09 0.65 0.82

Using the experimental data of [1], the authors of the invention obtained another empirical relationship for determining the concussion lesion of BO in the form

$$\mathrm{FROM}\mathrm{TO}=\mathrm{1,212}{W}^{0.165}.(21)$$

The conditions of applicability of the dependence (21) - 110≤W≤300 cm ³ .

Based on the analysis of the experimental data of [1, 5] and the calculation results, it was found that when the volume of the temporarily pulsating cavity is W <110 cm ³ SC <2.0, and when W> 300 cm ³ SC> 3.1.

The dependence of the size of the temporary cavity on the kinetic energy of PE sufficiently convincingly indicates that the parameters of the temporary cavity directly characterize the intensity of the shock when the BZ is not broken, and, to be more precise, they are indicators of exactly that part of the kinetic energy that is transmitted over the barrier to the underlying soft tissues BO.

Currently, most of both domestic and foreign researchers unambiguously associate the severity of pre-bronchial contusion injury in case of non-penetration of the BZ precisely with the phenomenon of the formation of a temporary cavity, and the above empirical dependencies can be taken as the basis for assessing the safety in the BZ during shelling.

The considered mathematical model for calculating the interaction parameters of the elements of the system "PE - tissue BZ - BO" allows you to quite satisfactorily predict them by calculation. So, the relative error in calculating the depth of the temporary cavity in the soft tissues of the BO (h) and its diameter at the base (d _in ) does not exceed 20%. The calculation results of the interaction parameters of the elements of the system “PE - tissue BZ-BO” are given in table 3.

Table 3 The values of the interaction parameters of the elements of the system “PE - fabric BZ-BO” for the conditions of non-penetration of BZ 6B5-11 and 6B11 BZH 6B11 (in _TP = 8 mm) BZH 6B23 (in _TP = 12 mm) Defined Parameters Striking element Striking element 9 mm PM bullet (V _c = 283 m / s) Steel ball weighing 1 g (V _s = 560 m / s) Bullet PM 9 mm 7N16 (V _c = 300 m / s) Steel ball weighing 1 g (V _s = 550 m / s) The final movement of the front surface of the BZ tissue package during the penetration of PE, Z _C , mm 6.41 4,57 7.76 4.65 The mass of the tissue package involved in the movement during the penetration of PE, m _TPK , g 1,476 0.751 3,248 1,167 The maximum speed of non-penetration of the BZ on a rigid base, V _PSNzh , m / s 126 343 178 440 Deflection of the back surface of the tissue bag Z _OKt , mm 44 29th 48 33

Continuation of Table 3 BZH 6B11 (in _TP = 8 mm) BZH 6B23 (in _TP = 12 mm) Defined Parameters Striking element Striking element 9 mm PM bullet (V _c = 283 m / s) Steel ball weighing 1 g (V _c = 560 m / s) Bullet PM 9 mm 7N16 (V _c = 300 m / s) Steel ball weighing 1 g (V _s = 550 m / s) The height of the bulge of the back surface of the BZ tissue package (depths of the cavity in the soft tissues of the BO), h, mm 36 21 36 21 Cavern inlet diameter, d _in , mm 86 55 93 62 The volume of the cavity in the soft tissues of BO, W, cm ³ 125.4 30,0 145.1 36.6 The degree of contusion lesion BO, SC 2.69 2.00 2.76 2.00

). Масса БЖ 6Б11 составляет 3,7 кг, а общая площадь защиты - 50 дм². Для изготовления компенсатора удара можно использовать арамидную ткань ТСВМ или аналог с плотностью $${\rho }_m=1430\frac{кг}{{м}^3}$$

и толщиной в_m=0,27 мм.Next, we evaluate the technical result of the proposed anti-shock device BZ. First, we evaluate the protective properties of the proposed BZ in comparison with the standard bulletproof. We will evaluate the protective properties for BZ 6B11, in which the fabric bag is made of 30 layers of TSVM-DZ fabric (in _TP = 12 mm, $${\rho }_{TP}=1430\frac{\mathrm{to}g}{m^3}$$

) The mass of the BZ 6B11 is 3.7 kg, and the total area of protection is 50 dm ² . For the manufacture of a shock absorber, you can use aramid fabric TSVM or an analog with a density $${\rho }_m=1430\frac{\mathrm{to}\mathrm{<figure-callout\; id="3"\; label="g\; m"\; filenames="00000122.png"\; state="\{\{state\}\}">g\; </figure-callout>}}{m^{}}$$

and a thickness of _m = 0.27 mm.

Find the mass of the proposed anti-shock device without taking into account the mass of the shock absorber 2 and the elastic filler 5 shock absorbers (figure 1, 2).

$$\begin{array}{l}{m}_{\mathrm{but}n\mathrm{at}}=m_{PP}+m_{\mathrm{to}\mathrm{at}}=S_{sP}(2{\mathrm{at}}_{PP}{\rho }_{PP}+{\mathrm{at}}_{T_{\mathrm{to}\mathrm{at}}}{\rho }_{T_{\mathrm{to}\mathrm{at}}})=\\ =0.15(2\cdot \mathrm{1,2}\cdot {10}^{-3}\cdot 1430+0.54\cdot {10}^{-3}\cdot 1430)=0.63\text{kg}\end{array}$$

where m _PP - the mass of the package of plates;

m _ku is the mass of shock compensators;

- толщина пакета пластин и тканевой основы компенсаторов удара соответственно;in _PP , $${\mathrm{at}}_{T_{\mathrm{to}\mathrm{at}}}$$

- the thickness of the package of plates and fabric base shock absorbers, respectively;

- плотность материала пакета пластин и тканевой основы компенсаторов удара соответственно.ρ _PP $${\rho }_{T_{\mathrm{to}\mathrm{at}}}$$

- the density of the material of the package of plates and fabric base shock absorbers, respectively.

Then the total mass of the proposed BZ with anti-shock device will be 4.33 kg, which does not exceed the mass of the regular BZ 6B23, accepted for supply in recent years (the mass of the BZ 6B23 is 4.5 kg).

If the proposed design of the BZ is defeated by small arms bullets and ammunition fragments, its protection must be considered as multilayer, consisting of a fabric package 1, two packages 6 (see figure 2) and shock absorber 4.

In this case, the limiting speed of the through non-penetration of the protection, provided that the mass and shape of the striker is preserved, can be determined by

$$V_{P\mathrm{FROM}{N}_{P\mathrm{TO}}}=\sqrt{V_{P\mathrm{FROM}{N}_{\mathrm{from}{\mathrm{at}}_{\mathrm{<figure-callout\; id="2"\; label="w\; t"\; filenames="00000122.png"\; state="\{\{state\}\}">w\; </figure-callout>}t}}}^2+2V_{P\mathrm{FROM}{\mathrm{<figure-callout\; id="2"\; label="N\; P\; P"\; filenames="00000122.png"\; state="\{\{state\}\}">N\; </figure-callout>}}_{PP}}^2},(22)$$

- предельная скорость непробития защитной композиции БЖ 6Б 11;Where $$V_{P\mathrm{FROM}{N}_{\mathrm{from}{\mathrm{at}}_{wt}}}$$

- the maximum speed of non-penetration of the protective composition BZ 6B 11;

- предельная скорость непробития пакета 6 и одной стенки компенсатора удара 4. $$V_{P\mathrm{FROM}{N}_{PP}}$$

- the maximum speed of non-penetration of the packet 6 and one wall of the shock absorber 4.

The maximum speed of non-penetration of the package and one wall of the shock absorber by Makarov pistol bullets can be determined by the dependence [6]

$$V_{P\mathrm{FROM}{N}_{PP}}=V_{P\mathrm{FROM}{N}_{P\mathrm{well}}}\sqrt{\mathrm{one}+\frac{m_{\mathrm{uh}}}{m_n^{\text{'}\text{'}}}},(23)$$

предельная скорость непробития жестко закрепленного пакета и стенки компенсатора удара;Where $$V_{P\mathrm{FROM}{N}_{P\mathrm{well}}}$$

ultimate speed of non-penetration of a rigidly fixed package and the wall of the shock absorber;

- масса пластины пакета и стенки компенсатора удара $$m_n^{\text{'}\text{'}}$$

- the mass of the plate plate and the wall of the shock absorber

. $$(m_n^{\text{'}\text{'}}={\mathrm{at}}_{P\mathrm{TO}\mathrm{At}}{\rho }_{PP}{S}_{PP}=1.47\cdot {10}^{-3}\cdot 1430\cdot {0.10}^2=21.02\cdot {10}^{-3}\text{kg)}$$

.

(подсчитан через $$V_{ПС{Н}_{ж}}$$

по данным табл.3)The maximum rate of non-penetration of a rigidly fixed package and the wall of the shock absorber can be determined through the specific unit impulse (i _in ), which for the TSVM-D tissue is on average $$i_{\mathrm{at}}=0.21\frac{N\cdot \mathrm{from}}{\mathrm{from}{\mathrm{<figure-callout\; id="2"\; label="m"\; filenames="00000122.png"\; state="\{\{state\}\}">m</figure-callout>}}^2\cdot mm}$$

(calculated through $$V_{P\mathrm{FROM}{N}_{\mathrm{well}}}$$

according to table 3)

$$V_{P\mathrm{FROM}{N}_{P_{\mathrm{well}}}}=i_{\mathrm{at}}{\mathrm{at}}_{P\mathrm{TO}\mathrm{At}}\frac{S_m}{m_{\mathrm{uh}}}(24)$$

,or $$V_{P\mathrm{FROM}{N}_{P_{\mathrm{well}}}}=i_{\mathrm{at}}{\mathrm{at}}_{P\mathrm{TO}\mathrm{At}}\frac{\pi \cdot d_{T\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="00000122.png"\; state="\{\{state\}\}">P</figure-callout>}}^2}{\mathrm{four}{m}_{\mathrm{uh}}}=0.21\cdot 1.47\frac{3.14\cdot {1.92}^2}{\mathrm{four}\cdot 5.95\cdot {10}^{-3}}=150\frac{\text{m}}{\text{from}}$$

,

where S _m - the area of the Midsection of the bullet in conjunction with a tissue bag,

$$S_m=\frac{\pi \cdot d_{T\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="00000122.png"\; state="\{\{state\}\}">P</figure-callout>}}^2}{\mathrm{four}}$$

d _TP - diameter bulging on the back surface of the tissue bag.

. $$d_{TP}=2\sqrt{z_{{\mathrm{to}}_{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="00000122.png"\; state="\{\{state\}\}">l</figure-callout>}}}^2+{\mathrm{at}}_{TP}{z}_{{\mathrm{to}}_l}}=2\sqrt{{(6.41\cdot {10}^{-3})}^2+8\cdot {10}^{-3}\cdot 6.41\cdot {10}^{-3}}=\mathrm{19,2}\cdot {10}^{-3}\text{m}$$

.

.Then $$V_{P\mathrm{FROM}{N}_{PP}}=V_{P\mathrm{FROM}{N}_{P\mathrm{well}}}\sqrt{\mathrm{one}+\frac{m_{\mathrm{uh}}}{m_n^{\text{'}\text{'}}}=}150\sqrt{\mathrm{one}+\frac{5.95}{21.02}}=170\frac{\text{m}}{\text{from}}$$

.

, что выше начальной скорости 9-мм пистолетной пули ПМ, составляющей 315 м/с.Finally, the ultimate speed of non-penetration of the protection of the proposed design of the BZ by the PM bullets will be $$V_{P\mathrm{FROM}{N}_{P\mathrm{TO}}}=\sqrt{V_{P\mathrm{FROM}{N}_{\mathrm{FROM}\mathrm{<figure-callout\; id="2"\; label="AT\; w\; t"\; filenames="00000122.png"\; state="\{\{state\}\}">AT\; </figure-callout>}wt}}^2+V_{P\mathrm{FROM}{\mathrm{<figure-callout\; id="2"\; label="N\; P\; P"\; filenames="00000122.png"\; state="\{\{state\}\}">N\; </figure-callout>}}_{PP}}^2}=\sqrt{{283}^2+{170}^2}=330\frac{\text{m}}{\text{from}}$$

that is higher than the initial speed of the 9-mm pistol bullet PM, component 315 m / s.

Next, we find a decrease in the degree of contusion of the personnel of the security forces in tissue BZ when using substrates in the form of shock compensators (KU) with and without air throttling in the anti-shock device. Assume that the temperature range for the use of the proposed BZ is from -50 to + 50 ° C.

If the proposed design of the BZ is damaged by small arms bullets and ammunition splinters, the maximum stresses on the surface of the soft tissues of the BO will be reduced to four times compared with the excess air pressure in the shock absorbers.

Assume that PE acts through the BZ fabric bag to the geometric center of bag 6 (see figure 2), which is located in front of the control unit.

, состоящей из ПЭ, тканевого пакета БЖ, пакета и лицевой тканевой поверхности КУ, воспользовавшись законом сохранения количества движения при взаимодействии.First, find the initial velocity of the moving system $$(V_{P{\mathrm{FROM}}_0})$$

, consisting of PE, a BZ tissue bag, a bag, and the front tissue surface of KU, using the law of conservation of momentum during interaction.

$$V_{P{\mathrm{FROM}}_0}=\frac{(m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}})V_{T{P}_{\mathrm{to}}}}{m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}}+m_n+m_{L_{\mathrm{to}\mathrm{at}}}},(25)$$

- масса лицевой тканевой поверхности КУWhere $$m_{L_{\mathrm{to}\mathrm{at}}}$$

- mass of the front tissue surface KU

; $$(m_{L_{\mathrm{to}\mathrm{at}}}\approx b^2{b}_m{\rho }_m\approx {0.10}^2\cdot 0.27\cdot {10}^{-3}\cdot 1430=3.86\cdot {10}^{-3}\mathrm{to}g\text{)}$$

;

m _n is the mass of the plate package;

(m _n ≈b ² b _n ρ _m ≈0.10 ² · 1.2 · 10 ^-3 · 1430 = 17.16 · 10 ^-3 kg).

The process of braking PE and movable BZ elements is divided into two stages. Stage I - braking of PE and moving BZ elements is carried out with closed openings of the control unit (the adiabatic process of air compression in the control unit is considered).

The equation of motion of the BZ mobile system in this case has the form:

$$m_{P\mathrm{FROM}}\frac{d{V}_{P\mathrm{FROM}}}{dt}=-\Delta P(x)S_{\mathrm{TO}\mathrm{At}},(26)$$

;Where $$m_{P\mathrm{FROM}}=m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}}+m_n+m_{L_{\mathrm{to}\mathrm{at}}}$$

;

V _PS - the speed of movement of PE and the mobile system of the BZ;

ΔР (x) - excess air pressure in the KU, depending on the degree of compression;

S _KU - _KU area, numerically equal to the area of its frontal projection.

$$\Delta P(x)=P_2(x)-P_0,(27)$$

where R ₂ (x) is the air pressure in the KU, depending on the degree of compression;

P ₀ - air pressure in the environment (can be taken equal to normal).

The air pressure in the KU with a change in air volume during adiabatic compression is determined by the expression [7]

или $$\frac{P_1}{P_2}={\left(\frac{W_2}{W_1}\right)}^{к},(28)$$

$$\frac{W_2}{W_{\mathrm{one}}}={\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}$$

or $$\frac{P_{\mathrm{one}}}{{\mathrm{<figure-callout\; id="2"\; label="P"\; filenames="00000122.png"\; state="\{\{state\}\}">P</figure-callout>}}_2}={\left(\frac{W_2}{W_{\mathrm{one}}}\right)}^{\mathrm{to}},(28)$$

- первоначальное давление воздуха в КУ в зависимости от температуры окружающей среды;Where $$P_{\mathrm{one}}\ge P_0^{*}$$

- the initial air pressure in the KU depending on the ambient temperature;

- давление воздуха в закрытом КУ при температуре T₀=-50°С, которое равно нормальному P₀=1·10⁵ Па, $$P_0^{*}$$

- air pressure in a closed boiler at a temperature T ₀ = -50 ° C, which is equal to normal P ₀ = 1 · 10 ⁵ Pa,

W ₂ - the current volume of air in the KU when it brakes PE and moving elements of the BZ;

W ₁ - the initial volume of air in KU at a pressure of P ₁ ;

k is the adiabatic index (for air, k = 1.4).

The air pressure in the KU at ambient temperature T ₁ (ρ ₁ = ρ ₀ , W ₁ = const, the process isochoric) is

$$P_{\mathrm{one}}=P_0^{*}\frac{T_{\mathrm{one}}}{{\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="00000122.png"\; state="\{\{state\}\}">T</figure-callout>}}_2}.(\mathrm{29th})$$

The current volume of air in KU will be equal

$${\mathrm{<figure-callout\; id="2"\; label="W"\; filenames="00000122.png"\; state="\{\{state\}\}">W</figure-callout>}}_2=W_{\mathrm{one}}-S_{\mathrm{TO}\mathrm{At}}x,(\mathrm{thirty})$$

where x is the deformation of KU.

From equations (27), (28) and (30) we obtain

$$\Delta P(x)=P_{\mathrm{one}}{\left(\frac{\psi S_{\mathrm{TO}\mathrm{At}}{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}}{\psi S_{\mathrm{TO}\mathrm{At}}{\mathrm{at}}_{\mathrm{to}\mathrm{at}}-S_{\mathrm{TO}\mathrm{At}}x}\right)}^{\mathrm{TO}}-P_0=P_{\mathrm{one}}{\left(\frac{\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}}{\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}-x}\right)}^{\mathrm{TO}}-P_0,(31)$$

where ψ is the coefficient of accounting for the volume of the elastic filler in KU (ψ≤1).

For foam rubber ψ = 0.8, and in its absence ψ = 1; in _KU - the thickness of KU.

, а через нее и степень сжатия воздуха в нем для момента достижения давления воздуха в КУ, равного P_2, при котором дросселирующие отверстия вскрываются или открываются.Find the magnitude of the deformation KU $$(x_{\mathrm{to}}^{\text{'}\text{'}})$$

, and through it the degree of compression of air in it for the moment when the air pressure in KU is equal to P _2, at which the throttling holes open or open.

For the case of adiabatic compression of air in the KU according to equation (28) we have

$$x_{\mathrm{to}}^{\text{'}\text{'}}=\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{TO}}}\right].(32)$$

Let us find the velocity of the PE and the BZ elements involved in the movement for the time moment when the air pressure in the KU reaches P ₂ under the assumption that the inertial mass of the KU involved in the movement of air and the elastic filler is small and can be neglected. To do this, we use equation (26) and, taking into account dependence (31), after integration we obtain

$$\begin{array}{l}{m}_{P{\mathrm{FROM}}_0}\frac{V_{P{\mathrm{FROM}}_0}^2}{2}-m_{P\mathrm{FROM}}^{*}\frac{V_{P\mathrm{FROM}}^{*2}}{2}=S_{\mathrm{TO}\mathrm{At}}\{\frac{P_{\mathrm{one}}}{\mathrm{one}-\mathrm{to}}[\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}-\\ -{\left(\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}\right)}^{\mathrm{to}}{\left(\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}-x_{\mathrm{to}}^{\text{'}\text{'}}\right)}^{\mathrm{one}-\mathrm{to}}]-P_0{x}_{\mathrm{to}}^{\text{'}\text{'}}\},(33)\end{array}$$

- скорость ПЭ и вовлеченных в движение элементов БЖ для момента времени, когда давление воздуха в КУ достигает Р₂, а $$x=x_{к}^{\text{'}}$$

;Where $$V_{P\mathrm{FROM}}^{*}$$

- the speed of PE and involved in the movement of the BZ elements for the point in time when the air pressure in KU reaches R ₂ , and $$x=x_{\mathrm{to}}^{\text{'}\text{'}}$$

;

; $$m_{P{\mathrm{FROM}}_0}=m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}}+m_n+m_{L_{\mathrm{to}\mathrm{at}}}$$

;

; $$m_{P\mathrm{FROM}}^{*}=m_{\mathrm{uh}}+m_{TP}^{*}+m_n+m_{L_{\mathrm{to}\mathrm{at}}}$$

;

. $$m_{TP}^{*}=\pi {(z_{\mathrm{to}l}+x_{\mathrm{to}}^{\text{'}\text{'}})}^2{\mathrm{at}}_{TP}{\rho }_{TP}$$

.

From here

$$\begin{array}{l}{V}_{P\mathrm{FROM}}^{*}=\sqrt{\frac{m_{P{\mathrm{FROM}}_0}}{m_{P\mathrm{FROM}}^{*}}{V}_{{}_{P{\mathrm{FROM}}_0}}^2-\frac{2S_{\mathrm{TO}\mathrm{At}}}{m_{P\mathrm{FROM}}^{*}}\{\frac{P_{\mathrm{one}}\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}}{\mathrm{one}-\mathrm{to}}[\mathrm{one}-{\left(\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}\right)}^{\mathrm{to}-\mathrm{one}}\times }\\ \overline{\times {\left(\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}-x_{\mathrm{to}}^{\text{'}\text{'}}\right)}^{\mathrm{one}-\mathrm{to}}]-P_0{x}_{\mathrm{to}}^{\text{'}\text{'}}\}}.(34)\end{array}$$

Substituting equation (32) into (34), we obtain

$$\begin{array}{l}{V}_{P\mathrm{FROM}}^{*}=\sqrt{\frac{m_{P{\mathrm{FROM}}_0}}{m_{P\mathrm{FROM}}^{*}}{V}_{P{\mathrm{FROM}}_0}^2-\frac{2S_{\mathrm{TO}\mathrm{At}}\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}}{m_{P\mathrm{FROM}}^{*}}\{\frac{P_{\mathrm{one}}}{\mathrm{one}-\mathrm{to}}\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}-\mathrm{to}}{\mathrm{to}}}\right]-}\\ \overline{-P_0\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}\right]\}}.(35)\end{array}$$

Stage II - braking of PE and BZ elements involved in the movement occurs during operation of the throttle device KU (P ₂ = const, ΔP ₂ = P ₂ -P ₀ ). The equation of motion of PE and the elements of the BZ involved in the movement when exposed to the KU has the form:

$$m_{P\mathrm{FROM}}\frac{V_{P\mathrm{FROM}}d{V}_{P\mathrm{FROM}}}{dx}=-\Delta P_2{S}_{\mathrm{to}\mathrm{at}}.(36)$$

Separating the variables and integrating expression (36), we obtain

$$\frac{m_{P\mathrm{FROM}}^{*}{V}_{P\mathrm{FROM}}^{*2}}{2}=S_{\mathrm{TO}\mathrm{At}}\Delta P_2(x_{\mathrm{to}}-x_{\mathrm{to}}^{\text{'}\text{'}}),(37)$$

where x _k is the final displacement of the BZ tissue package or the maximum degree of KU deformation during its inhibition.

From here

$$x_{\mathrm{to}}=x_{\mathrm{to}}^{\text{'}\text{'}}+\frac{m_{P\mathrm{FROM}}^{*}{V}_{P\mathrm{FROM}}^{*2}}{2S_{\mathrm{TO}\mathrm{<figure-callout\; id="2"\; label="At\; \Delta \; P"\; filenames="00000122.png"\; state="\{\{state\}\}">At\; </figure-callout>}}\Delta P_{}{}_2}.(38)$$

Substituting equations (32), (35) into expression (38), we obtain

$$\begin{array}{l}{x}_{\mathrm{to}}=\psi {\mathrm{at}}_{\mathrm{to}\mathrm{at}}\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}\right]+\frac{\mathrm{one}}{2S_{\mathrm{to}\mathrm{at}}\Delta P_2}\{\{m_{P{\mathrm{FROM}}_0}{V}_{P{\mathrm{FROM}}_0}^2-2S_{\mathrm{to}\mathrm{at}}\psi {\mathrm{at}}_{\mathrm{to}\mathrm{at}}\times \\ \times \{\frac{P_{\mathrm{one}}}{\mathrm{one}-\mathrm{to}}\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}-\mathrm{to}}{\mathrm{to}}}\right]-P_0\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}\right]\}\}\},(39)\end{array}$$

.where ΔP ₂ = P ₂ -P ₀ ; $$x_{\mathrm{to}}^{\text{'}\text{'}}<x_{\mathrm{to}}\le \psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}$$

.

The degree of impact of PE on BO in the proposed tissue BZ depends on the air pressure in KU P ₂ and the time of braking of PE and the BZ elements involved in the movement.

The lower the air pressure in KU R ₂ , the lower the degree of contusion of BO. Next, the task of optimizing the parameters of the anti-shock device with a special control unit is solved as follows:

1) knowing the parameters of the means of destruction (PE), the characteristics of tissue BZ and the conditions of impact, we determine the initial velocity of exposure to PE and involved in the movement of elements of the BZ on the CS according to

$$V_{P{\mathrm{FROM}}_0}=\frac{m_{\mathrm{uh}}{V}_{\mathrm{from}}}{m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}}+m_n+m_{L\mathrm{TO}\mathrm{At}}}.(40)$$

по зависимости (35) и $$x_{к}^{\text{'}}$$

по зависимости (32).2) asking step in excess air pressure in the KU (ΔР), determine P ₂ according to dependence (39), provided that x _to ≤ψ in _KU . Then determined $$V_{P\mathrm{FROM}}^{*}$$

according to (35) and $$x_{\mathrm{to}}^{\text{'}\text{'}}$$

according to (32).

Let us find the diameter of the throttling hole through which air flows out of the KU when braking the BZ tissue package, which provides constant air pressure in it (P ₂ = const).

First, we find the braking time of the BZ tissue package at stage II (at P ₂ = const), which is equal to the air throttling time from the KU.

To do this, we use equation (36), integrating which, we obtain

$$t_{\mathrm{to}}=\frac{m_{P\mathrm{FROM}}^{*}{V}_{P\mathrm{FROM}}^{*}}{S_{\mathrm{TO}\mathrm{At}}\mathrm{<figure-callout\; id="2"\; label="\Delta \; P"\; filenames="00000122.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{P}_{}{}_2}.(41)$$

For the case of the maximum displacement of air from the KU (W ₁ = 0), the time of its consumption is

$$t_{\mathrm{to}}=\frac{\psi S_{\mathrm{TO}\mathrm{At}}{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}{\rho }_{\mathrm{one}}}{\dot{m}},(42)$$

where ρ ₁ is the density of air in the KU at a temperature of T ₁ ;

- массовый секундный расход воздуха из КУ. $$\dot{m}$$

- mass second air flow from KU.

Equating equations (41) and (42), we obtain

$$\frac{m_{P\mathrm{FROM}}^{*}{V}_{P\mathrm{FROM}}^{*}}{S_{\mathrm{TO}\mathrm{At}}\mathrm{<figure-callout\; id="2"\; label="\Delta \; P"\; filenames="00000122.png"\; state="\{\{state\}\}">\Delta \; </figure-callout>}{P}_{}{}_2}=\frac{\psi S_{\mathrm{TO}\mathrm{At}}{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}{\rho }_{\mathrm{one}}}{\dot{m}}.$$

From here

$$\dot{m}=\frac{\psi S_{\mathrm{TO}\mathrm{At}}^2{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}{\rho }_{\mathrm{one}}\Delta P_2}{m_{P\mathrm{FROM}}^{*}{V}_{P\mathrm{FROM}}^{*}}.(43)$$

For the case of the outflow of air through the hole from the vessel with a critical speed V _cr mass second consumption will be equal to [7]

$$\dot{m}=\alpha \frac{\pi d_0^2}{\mathrm{four}}\cdot \frac{P_2}{\sqrt{R{T}^{*}}}\sqrt{\frac{2\mathrm{to}}{\mathrm{to}+\mathrm{one}}}{\left(\frac{2}{\mathrm{to}+\mathrm{one}}\right)}^{\frac{\mathrm{one}}{\mathrm{to}-\mathrm{one}}},(44)$$

where α is the coefficient of air flow;

d ₀ is the diameter of the hole through which the air flows;

P ₂ - air pressure at the inlet to the hole (taken equal to the air pressure in KU);

- газовая постоянная; $$R=\frac{R\mu }{\mu }$$

- gas constant;

Rµ is the universal gas constant, $$R_{\mu }=8314\frac{D\mathrm{well}}{\mathrm{to}m\mathrm{about}lb\cdot \mathrm{TO}};$$

µ is the molecular mass of gas (air);

T ^* - gas braking temperature (can be taken equal to the air temperature at the inlet to the hole, i.e. T ^* = T ₂ ).

The critical velocity of gas flow through the hole is determined by the dependence [7]

$$V_{\mathrm{to}R}=\sqrt{\frac{2\mathrm{to}}{\mathrm{one}+\mathrm{to}}RT{.}^{*}}$$

We find the final air temperature in KU from the equation of state

$$T^{*}={\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="00000122.png"\; state="\{\{state\}\}">T</figure-callout>}}_2=\frac{P_2{W}_2}{mR}=\frac{P_2\left(W_{\mathrm{one}}-S_{\mathrm{TO}\mathrm{At}}{x}_{\mathrm{to}}^{\text{'}\text{'}}\right)}{W_{\mathrm{one}}{\rho }_{\mathrm{one}}R}=\frac{P_2\left(\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}-x_{\mathrm{to}}^{\text{'}\text{'}}\right)}{\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}{\rho }_{\mathrm{one}}R},(45)$$

where for air under normal conditions (P ₀ = 1 · 10 ⁵ Pa, T ₁ = 293 K)

$$R=286.6\frac{\text{J}}{\text{kg}\cdot \text{TO}},$$

$${\rho }_{\mathrm{one}}=\mathrm{1,293}\frac{\text{<figure-callout id="3" label="kg m" filenames="00000122.png" state="{{state}}">kg </figure-callout>}}{{\text{m}}^{}}.$$

Substituting dependence (32) into dependence (45), we obtain

$${\mathrm{<figure-callout\; id="2"\; label="T"\; filenames="00000122.png"\; state="\{\{state\}\}">T</figure-callout>}}_2=\frac{P_2{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}}{{\rho }_{\mathrm{one}}R}.(46)$$

The final density of air at its pressure P ₂ for the process under consideration is equal to

$${\mathrm{<figure-callout\; id="2"\; label="\rho "\; filenames="00000122.png"\; state="\{\{state\}\}">\rho </figure-callout>}}_2={\rho }_{\mathrm{one}}{\left(\frac{P_2}{P_{\mathrm{one}}}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}.(47)$$

Equating expressions (43) and (44), we obtain

$$\frac{\psi S_{\mathrm{TO}\mathrm{At}}^2{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}{\rho }_{\mathrm{one}}\Delta P_2}{m_{P\mathrm{FROM}}^{*}{V}_{P\mathrm{FROM}}^{*}}=\alpha \frac{\pi d_0^2}{\mathrm{four}}\cdot \frac{P_2}{\sqrt{R{T}^{*}}}\sqrt{\frac{2\mathrm{to}}{\mathrm{to}+\mathrm{one}}}{\left(\frac{2}{\mathrm{to}+\mathrm{one}}\right)}^{\frac{\mathrm{one}}{\mathrm{to}-\mathrm{one}}}.$$

From here

$$d_0=2\sqrt{\frac{\psi S_{\mathrm{TO}\mathrm{At}}^2{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}{\rho }_{\mathrm{one}}(P_2-P_0)}{\pi \alpha P_2{m}_{P\mathrm{FROM}}^{*}{V}_{P\mathrm{FROM}}^{*}}}\sqrt{R{T}^{*}}\sqrt{\frac{\mathrm{to}+\mathrm{one}}{2\mathrm{to}}}{\left(\frac{2}{\mathrm{to}+\mathrm{one}}\right)}^{\frac{\mathrm{one}}{\mathrm{to}+\mathrm{one}}}.(48)$$

To assess the cushioning properties of KU without throttling holes, it is necessary to establish a relationship between the final movement of the BZ tissue package or the degree of KU deformation and the air pressure in it.

Using equation (26) and solving it in the same way as when deriving dependence (33), we obtain

$$\frac{m_{P{\mathrm{FROM}}_0}{V}_{P{\mathrm{FROM}}_0}^2}{2}=S_{\mathrm{TO}{\mathrm{At}}_0}\left\{\frac{P_{\mathrm{one}}}{\mathrm{one}-\mathrm{to}}\left[\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}-{\left(\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}\right)}^{\mathrm{to}}{\left(\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}-x_{\mathrm{to}}^{\text{'}\text{'}}\right)}^{\mathrm{one}-\mathrm{to}}\right]-P_0{x}_{\mathrm{to}}\right\}.(49)$$

In this case, ψ can be taken equal to unity, i.e. KU without elastic filler.

The final movement of the BZ tissue package (x _k ) will be found through the air pressure in the KU, equal to P ₂ and corresponding to the maximum KU deformation.

Using equation (28), we obtain

$${\mathrm{<figure-callout\; id="2"\; label="W"\; filenames="00000122.png"\; state="\{\{state\}\}">W</figure-callout>}}_2=W_{\mathrm{one}}{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}.(\mathrm{fifty})$$

Given that W ₁ = ψS _KU in _KU , and W ₂ = W ₁ -S _KU x _k , equation (50) takes the form:

$$x_{\mathrm{to}}=\psi {\mathrm{at}}_{\mathrm{TO}\mathrm{At}}\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}}{\mathrm{to}}}\right].(51)$$

Then equation (49) takes the form:

$$\frac{m_{P{\mathrm{FROM}}_0}{V}_{P{\mathrm{FROM}}_0}^2}{2}=\psi S_{\mathrm{TO}\mathrm{At}}{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}\left\{\frac{P_{\mathrm{one}}}{\mathrm{one}-\mathrm{to}}\left[\mathrm{one}-{\left(\frac{P_{\mathrm{one}}}{P_2}\right)}^{\frac{\mathrm{one}-\mathrm{to}}{\mathrm{to}}}\right]-P_0{\left[\mathrm{one}-\left(\frac{P_{\mathrm{one}}}{P_2}\right)\right]}^{\frac{\mathrm{one}}{\mathrm{to}}}\right\}.(52)$$

. При этих с условиях скорость движения тканевого пакета штатного БЖ 6Б11 в момент м прекращения внедрения в него ПЭ составит V=240 -. На этой дальности БО получает степень контузии чуть меньше III (CK=2,70). При этом начальное давление на границе раздела тканевый пакет БЖ - мягкие ткани БО составляетWe will evaluate the effectiveness of using an anti-shock device in comparison with a standard tissue BZ 6B11 in case of damage with 9 mm PM bullets at a distance of 5 m (range of 100% non-penetration of a regular BZ 6B11). The speed at which a bullet encounters a BZ fabric bag at this range $$V_{\mathrm{from}}=300\frac{\text{m}}{\text{from}}$$

. Under these conditions, the speed of movement of the fabric pack of regular BZ 6B11 at the time m of termination of the introduction of PE into it will be V = 240 -. At this range, the BO gets a degree of concussion slightly less than III (CK = 2.70). At the same time, the initial pressure at the interface of the BZ tissue package - soft tissue BO is

и равно Р_шт=30,0 МПа. $$P_{wt}=\frac{{\rho }_{MT}{V}_{T{P}_{\mathrm{to}}}^2}{2}$$

and equal to P _pc = 30.0 MPa.

The initial speed of the tissue package of the proposed BZ will be found by dependence (40).

$$V_{P{\mathrm{FROM}}_0}=\frac{m_{\mathrm{uh}}{V}_{\mathrm{from}}}{m_{\mathrm{uh}}+m_{T{P}_{\mathrm{to}}}+m_n+m_{L\mathrm{TO}\mathrm{At}}}=\frac{5.95\cdot {10}^{-3}\cdot 300}{(5.95+\mathrm{1,476}+17.16+3.86)\cdot {10}^{-3}}=62.8\frac{\text{m}}{\text{from}}$$

The calculation results for evaluating the optimal characteristics of the proposed design of the anti-shock device of the fabric BZ with shock compensators with throttling holes and without them and the parameters of the air condition in them, as well as the degree of damage to the personnel of the security forces in the fabric BZ of the proposed design at a shelling distance of 5 m from 9- mm PM are presented in table 4.

Table 4 in _KU , 10 ^-3 m

$$x_{\mathrm{to}}^{\text{'}\text{'}},{\text{10}}^{\text{-3}}$$

$$V_{P\mathrm{FROM}}^{*},\text{m / s}$$

T ₂ ° K P ₂ , 10 ⁵ Pa d ₀ , 10 ^-3 m $$\dot{m},\text{kg / s}$$

λ Note KU without throttling holes 10 9.55 - 1222 100.0 - - 12.1 $$x_{\mathrm{to}}=x_{\mathrm{to}}^{\text{'}\text{'}}$$

; ψ = 1 fifteen 13.77 - 963 43.5 - - 28,2 Also twenty 17.63 - 833 26.1 - - 47.8 - << - 25 21.19 - 752 18.3 - - 69,4 - << - Throttle control unit 10 7.48 27.66 1057 60,2 40.70 7.02 20.3 ψ = 0.8; α = 0.72 fifteen 10.34 33,99 782 21.0 39.76 2,56 60.0 Also twenty 12.92 33.85 685 13,2 42.45 1.80 98.4 - << - 25 14.55 37.58 596 8.1 41.45 1.12 169.0 - << -

where in table 4 $$\lambda =\frac{\mathrm{four}{P}_{w\mathrm{<figure-callout\; id="2"\; label="t\; \Delta \; P"\; filenames="00000122.png"\; state="\{\{state\}\}">t\; </figure-callout>}}}{\Delta P_{}}.$$

From the point of view of acceptable sizes, thickness should be considered as the most rational thickness of KU in the range of 15 ... 20 mm. The diameter of the throttle hole should be no more than 40 mm. Then the maximum value of the ratio of the area of the holes to the area KU will be

$$\frac{S_0}{S_{\mathrm{to}\mathrm{at}}}=\frac{\pi d_0^2}{\mathrm{four}{\mathrm{at}}^2}=\frac{\pi {\left(40\cdot {10}^{-3}\right)}^2}{\mathrm{four}{\left(0.1\right)}^2}=1.25\cdot {10}^{-\mathrm{one}}$$

or S ₀ : S _ku = 1: 8.

Thus, the ratio of the area of one or more initially hermetically sealed openings in the KU to its frontal area should not exceed 1: 8.

An analysis of the data in Table 4 shows that when using an anti-shock device with KU without throttling holes, the initial pressure at the BZ - soft tissue BO interface with a KU thickness of 10 ... 25 mm compared to the standard BZ 6B11 decreases by 12 ... 69 times, and when using KU with throttling holes for the same interval of thickness KU decreases by 20 ... 169 times.

, что соответствует весу тела массой 8,7…12,1 кг.The proposed design of the BZ with anti-shock device provides some buoyancy of the personnel of the security forces. So, when using KU with a thickness of 15 ... 20 mm with a total protection area S _s = 0.5 m ^{2, the} buoyancy force of water will be equal to $$F_{nd}=\left(2{\mathrm{at}}_{PP}+{\mathrm{at}}_{\mathrm{TO}\mathrm{At}}\right)S_s{\rho }_{\mathrm{at}}g=\left[2\cdot \mathrm{1,2}+(\mathrm{fifteen}...\mathrm{twenty})\right]\cdot {10}^{-3}\cdot 0.5\cdot 1000\cdot 9.81=85.35...109.87\text{H}$$

, which corresponds to a body weight of 8.7 ... 12.1 kg.

The proposed BZ with an anti-shock device is not inferior to the regular bulletproof one, significantly reduces the degree of damaging effect on the BO when the BZ is not penetrated by various PEs, and when immersed in water it provides buoyancy almost at the level of the double weight of the BZ, which gives a positive effect, which consists in increasing the survivability of the personal the composition of the units of power structures in tissue BZ.

Information sources

1. The conceptual framework for creating personal protective equipment. - Part I. Body armor / V.I. Baidak and others. Under the general. ed. V.G. Mikheeva. - M .: Arms. Policy. Conversion, 2003 .-- 338 p.

2. Znakhurko V.A. Outfit of a serviceman. / V.A. Znakhurko et al. - Penza: PAII, 2005 .-- 148 p.

3. Pat. RF №2395055, 11/27/2007, F41Н 1/02.

4. The design, theory and calculation of artillery shells and warheads. / B.C. Ablov et al. - Penza: PVAIU, 1979.- 504 p.

5. Ivliev Yu.G. Bronvic contusion injury (analysis of probable mechanisms of occurrence, assessment methods and prevention methods) / Yu.G. Ivliev, V.N. Grivkov, V.V. Chivilev // Actual problems of protection and safety: Tr. 4th All-Russian. conf. - St. Petersburg: NPO "Special Materials", 2001. - S.324-330.

6. Deryabin P.N. The physical basis of the defeat of manpower in body armor and ways to increase its survivability. / P.N. Deryabin // Monograph. - Penza: PAII, 2000 .-- 123 p.

7. The basics of heat engineering. / V.V. Burlov et al. - Penza: PAII, 2003 .-- 231 p.

Claims (1)

A fabric bulletproof vest containing chest and dorsal sections, equipped with TSBM packages of aramid fabric placed in covers, having an anti-shock device on its inner surface, consisting of a shock absorber and a substrate, which consists of a layer of square packets flexibly connected to each other around the perimeter in the form of glued together layers of aramid fabric TSVM and shock compensators with one or more throttling holes, characterized in that the substrate additionally includes a package of plates from a flexible layer about square packets interconnected around the perimeter in the form of layers of aramid fabric TSVM glued together, placed on the back of the substrate so that the centers of mass of its square elements are located opposite the corner points of the joint shock absorbers.

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