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Development of armor protection for combat equipment
is based on an integrated study of the mechanisms of interaction
of the threat and the armor material or pattern. The interaction
mechanisms are studied both by actual experiments and by computer
simulation.
We have the whole range of facilities required
for such experiments, including our own proving grounds, test
laboratories equipped with all kinds of small arms and artillery
guns (e.g. 100mm artillery gun); powerful up-to-date computing
systems and a number of 2D and 3D computer programs for computation
of complex armor arrangements.
Below you can find a number of armor arrangements
and their interaction mechanisms with the appropriate threat
studied by our experts:
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Spaced armor (dual-plate armor)
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Fig.1 Diagram of shaped
charge jet penetration
into the spaced armor
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Spaced armor is the simplest protective arrangement
after the homogeneous armor. The effect of spacing in defeating
the shaped charge jet is based on the relationship between
the penetration depth and the charge/main plate distance.
The screen (the front plate) changes the optimum distance
of the charge initiation from the main armor.
The investigators found out that the spaced
armor efficiency depends on the shaped charge quality, the
distance between the front and the pack plates, the front
plate thickness, the impact obliquity and a number of other
minor factors.
The total increase of the counter-HEAT effect
resistance due to spacing the armor plates is from 9 to 18
per cent.
The spaced armor efficiency against the KE ammunition
is determined by a destabilizing and destructive effect of
the screen on the penetrator.
The investigations show that the actual increase
of protection level due to spacing the armor can amount to
6-8%, and in some cases when the distance between the plates
can be made as much as 2-2.5m, this increase can amount to
25-30%.
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| Fig.2 X-ray of interaction of the long
penetrator and spaced armor against the result of 2D computer
simulation |
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Grill screens (principle of operation)
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Behind-the-armor anti-fragmentation screen
Ensures: 80% reduction of the scatter angle of secondary
fragments;
4.5-5.0 times reduction of the shock wave amplitude.
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Grill screen
Ensures 0.5-0.65 probability of destruction of HEAT warheads
of AT grenades (PG-7, PG-9) without shaped charge jet formation.
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Damping armor screen
Reduces impact and crater effects on the main armor; ensures
protection level increase against 12.7mm AP bullets.
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Combined laminated armor
 Laminated
armor with low-density filler follows the spaced armor in complexity.
This armor was developed against HEAT-warhead threats and is efficient
mainly against HEAT ammunition.
A wide range of materials can be used as fillers in
such type of armor: high-strength steels, titanium, aluminum, ceramics,
glass fiber laminates etc.
The investigations show that this armor can ensure
15-30% weight reduction as compared to homogeneous steel armor;
and the largest gain is provided by the armor filled with the glass
fiber laminates.
As for the protection of this armor against KE projectiles,
there are no salient preferences. For example, for obliquities of
40 and less the maximum effect is gained by targets with a stronger
filler, and for obliquities of more that 60 the protection increases
with reduction of the filler density. But complete absence of the
filler (air spacing) results in detrimental effect.
Armor with cellular filler
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This type of armor belongs to so called "semi-active"
protection systems in which protection is based on the using
the energy of the attacking weapon.
The method was suggested by the hydrodynamics
institute of the Siberian division of the Russian Academy
of Sciences and implies the following:
When the shaped charge jet gets into a metal-wall
closed space filled with a liquid or quasi-liquid material,
a shock wave is generated in the liquid with its start from
the jet tip. The shock wave reflected from the walls comes
back to the jet axis which makes the liquid move in the same
direction. The liquid moves at high velocity and closes the
crater, which results in deceleration and disruption of the
jet.
Such armor type can provide 30-40% gain in counter-HEAT
effect protection.
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Spall-type armor
Fig.1 Principle of operation of spall-type armor |
Protection principle is actually the same as
that of the armor with cellular filler and is based on using
the energy of the shaped charge jet. When the jet reaches
the free back surface of the target, the target portions at
the free back surface effected by the shock wave start moving
in the same direction as the jet.
If we arrange a set-up which will make the target
material move against the jet, the energy of the target portions
flying from the free surface will be used to disrupt the jet.
Such set-up can be arranged by making hemispherical or parabolic
cavities at the target back.
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Bulging armor
This armor also belongs to semi-active armor type.
The armor consists of three layers: a plate, a spacer
and a thin sheet. The principle of operation of the armor is shown
in Fig.1.
When the jet penetrates the plate, internal stresses
are induced which result first in bulging of the plate back (a)
and then in destruction of the back surface (b). At the same time
both the spacer and the thin sheet also undergo significant bulging.
By the time the jet perforates the spacer and the sheet, the sheet
has already started moving off the back surface of the plate (c).
As there is some obliquity between the movement directions of the
jet and the sheet, at a certain instant the sheet starts to run
upon the jet and disrupts it.
Increase of the protection level of the bulging armor
can amount to 40% as compared to homogeneous armor of the same weight.
Such armor was used on some Russian MBTs.
Fig.1 Shaped charge jet penetration
into the bulging armor (a, b, c)
1-st Generation add-on ERA ("Contact")
Principle of operation:
When the ERA tile is perforated by a shaped charge
jet, the explosive inside the tile detonates and the metals plates
of the tile casing start flying apart. During their flight they
cross the jet trajectory. Therefore a part of the jet is used for
penetration of the flying plates, and a side pulse from the collision
destabilizes the jet.
Due to ERA the efficiency of HEAT warheads is reduced
by 50-80%.
As for KE ammunition, this type of ERA does not affect
its efficiency.
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- weight saving: 10-20 times (as compared to RHA)
- Low price
- Manufacturability
- Easy mounting and maintenance (by the crew members)
- Immunity to small arms fire and incendiary mixtures
(napalm)
- Repairability using electric and gas welding
- Guaranteed service life: 10 years
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Protected area, % |
Weight, kg |
| Turret |
Hull front |
Hull side |
Turret |
Hull front |
Hull side |
| ERA kit for T-72S |
62 |
82 |
32 |
422 |
288 |
300 |
| Blazer ERA kit |
70...75 |
80 |
0 |
876 |
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ERA box and 4S20 ERA tiles for Contact
ERA kit |
X-ray of interaction of the shaped charge
jet and an ERA tile |
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2-nd Generation ERA (integrated variant)
This ERA type is effective both against HEAT-warhead
and KE ammunition.
Main challenges in developing the integrated ERA:
- how to ensure effective
detonation of the ERA tiles from KE munition the velocity of which
is not high enough;
- how to provide a strong
enough side pulse to destabilize and destruct the KE penetrator.
These problems have been solved by using special design
of ERA boxes (Fig.1).
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The cover of the ERA box is made of a thick
high-strength steel plate; when it is hit by a KE penetrator,
a flow of high-velocity fragments is generated, which causes
detonation of the ERA tiles. The counteraction of the flying
thick cover is enough to drastically reduce the armor penetration
of both HEAT warheads and KE penetrators.
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Fig.1 Integrated ERA box |
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Integrated ERA can increase protection of the tank
against HEAT warheads by factors of 1.5-1.8 and against
KE penetrators by factors of 1.2-1.5.
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Integrated ERA module on the hull side |
Integrated ERA module on the hull front |
Integrated ERA module on the turret side |
Some projects of ERA upgrading
...Under construction...
...Under construction...
...Under construction...
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