Blast Effects and Target Analysis Flashcards
What is the definition of an explosion?
The violent decomposition of energetic material releases heat and rapidly expanding gases, causing extreme pressure and structural rupture.
High explosives are split into two groups, what are they and give an example for each group?
Primary : Sensitive to heat shock or friction. Lead azide, Mercuary fulminate, lead styphlinate.
Secondary: Less sensitive to stimuli. RDX, TNT.
CDCS
What factors affect the Velocity of Dentonation (VoD) of explosives?
Charge density
Charge diameter
Degree of confinement
Strength of detonator
How does burning to detonation occurs?
Abrupt flame front acceleration creates a shock wave in confined explosives increasing pressure, burning rate, and potentially reaching sonic velocity.
FAE: Greater Range, Higher Heat
What are the advantages of Fuel Air Explosives?
Greater Range: FAE creates larger overpressures at greater distances than HE.
Higher Heat: FAE explosions are 3 to 5 times hotter than HE due to low oxygen in the structure.
In your own words, explain Rarefaction
Area of low pressure immediately following the shock wave
In your own words, explain Reflection
When the blast wave is thrown back at an angle to the original path.
In your own words, explain the definition of a blast?
An explosion causes a violent disruption, releasing heat, gases, and a shock wave from the center
What is the formular used for the probability product rule?
Pk = Ph x Pr x PL
DND
List three levels of damage which an ammunition designer may wish to achieve in reagrds to Target Analysis?
Disablement
Neutralized
Destroyed
AP
On the battlefield, people appear as many different targets. What factors affect their vunlerability and explain each of them?
Attitude (target area presented)
Protection ( buildings, PPE, equipment)
What are the two sources employed in ammunition design. Breifly describe each below:
Kinetic Energy: In the form of a solid missile, which dissipates its energy on impact & requires no triggering device to control the energy release.
Chemical Energy: A substance with high potential energy relative to its mass that can release energy when triggered, like HE, initiated by a fuze.
Overpressure from a chemical energy source (blast) is one of the four basic techniques used in the attack of an aircraft in flight. What are the other three?
Kinetic energy
Special kinetic energy
Shaped charges
List the standard criteria used in the Defence industy for aircraft damage?
KK-Kill - immediate disintegration.
K-Kill - destroyed in less than 10 secs.
A-Kill - destroyed in less than 5 mins.
B-Kill - defeated in less than 5 hours.
C-Kill - mission is not achieved
E-Kill - mission might be complete but repairs required before flight
What effect does altitude have on a blast warhead?
To be effective a blast wave requires a medium through which it can travel. As the medium becomes less dense, the effect of a blast warhead decreases.
BFFSSS
Cluster disc warheads are one type of attack available in the engagement of aircraft in flight, name three others?
Blast
Fragmentation
Fragmentation plus blast
Special kinetic energy
Shaped charges
Sub-projectiles
What percentage of fragmentation in an anti-aricraft warhead is wasted?
80%
Since a large amount of fragmentation in an aircraft warhead is wasted, how can a fragmenation warhead be made more efficient?
By arranging the fragments and HE so that the fragments are projected in a narrow beam or band in one chosen direction (prederential fragmentation).
RSPFCRS
What are the types of Armour used?
Rolled Homogeneous Armour (RHA)
Spaced Homogeneous
Ply
Face hardened
Composite (Chobham)
Reactive – Explosive Reactive Armour (ERA)
Slat (Bar)
Barrelling, shattering and lateral stresses are possible causes of shot faliure. Explain shattering?
Raising the hardness of a steel shot increases its compressive strength but makes it brittle.
At high velocities, tensile hoop stresses in the nose (small cross-sectional area) can cause failure.
The shot may form longitudinal cracks, and at extreme loading, it can “shatter,” disintegrating catastrophically.
Explain the damage assessment cirteira Firepower (F) Kill
When the main armament or associated equipmen ha been damaged and inoperable or ireparable on a battle field or the crew have been rendered incapable of operating it
LHSO
What are the four Behind Armour Effects (BAE)?
BAE Types
Luminosity
Heat and fire
Spalling
Overpressure
In combined kinetic/chemical energy attack, what problem arises in relation to the chemical energy portion of the round?
Kinetic energy penetrates armor without fuzing, but initiating the CE source behind armor is challenging due to intense shocks during impact and penetration.
Lengthening the barrel and rocket assist are two ways of increasing penetration of armour. Name the other three?
Use of segmented long rod penetrators
Lengthening the projectile
Improve steadiness of shot
ART
Severity of a casualty or wound type is dependent on what three factor WRT energy transfer?
Actual energy transfer
Rate of transfer from projectile
Tumbling and yawing
CTQV
The ammunition designer can control the size of fragments obtained from a shell body by varing what design features?
Case material and its mechanical properties
Thickness of the wall
Quantity of explosive and its position
Velocity of detonation
ACD
In some extent, a designer can control fragment velocity by varing what?
Amount of explosive behind the fragment wall
Charge density and velocity of detonation
Density of the wall material
How does orientation of projectile affect distribution of fragments?
The best distribution occurs when the projectile’s axis is vertical; moving away loses fragmentation.
Explain how a High Explosive Squash Head (HESH) attack defeat armour plate and the effect it causes?
Where is the point of initiation of a HESH round?
The base/rear of the projectile
What is reverse impact detonation (RID)?
If detonation occurs before the fuze activates, the shock wave travels in the wrong direction.
SHHA
With regards to external ballistics, how is air resistance reduced when designing a kintetic energy round?
Small cross-sectional area
High Mass
High Velocity
Aerodynamic design
SDB
When an Amour Piercing Fin Stabilised Discaring Sabot (APFSDS) Round is fires from a rifled barrel, how is the projectile rate of spin reduced?
Slipping
Driving
Band
ARG
The sabot of an APSDS projectile is difficult to discard since the low rate of spin provides insufficient centrifugal froce. What forces are utilised to assist with discarding the sabot?
Aerodynamic
Residual gas pressure
Gas pressures
Aero
What lengths to diameter ratios are applied to the following forms of stabilisation?
1. Spin
2. Fin
7:1 = Spin
15:1 = Fin
C-SLRS
What factors affect performance of a shaped charge?
Cone Diameter
Shape of Liner
Liner Material (Copper, Steel, Aluminium)
Rate of Spin
Stand-Off Distance
What stand off distance achieves peak performance of a shaped charge?
5 times cone diameter
What is the optimum stand off for the munroe effect? EFP penetraintng?
1 to 1000 times cone diameter
Select the correct words to complete the following statement
The _____ of the energy from a charge of high explosives is achived by hollowing out the front face of a slab of high explosives to give a ____ shape..
Keeps on going - find powerpoint.
