Tatget Analysis Flashcards
What is the definition of an explosion?
A nuclear, chemical or physical process leading to a sudden release of energy
High explosives are split into two groups, what are they and give an example for each group?
Primary explosives- lead azide
Secondary explosives- COMP B
What factors affect the V of D of explosives?
Strength of detonators
Density of the charge
Charge diameter
Degree of confinement
Explain how burning to detonation occurs?
Occurs when there is an abrupt acceleration of the flame front until it becomes a shock wave
When explosives are confined in a tube and ignited at one end. The gas generated cannot escape
Pressure builds up the burning rate increases and pulses can be generated which may accelerate the building rate to sonic velocity
In your own words, explain rarefraction?
The area of low pressure immediately following the positive phase.
In your own words explain reflection?
Reflection is when a blast wave hits an object and returns back in the opposite direction
What are the advantages to a fuel air explosion?
Larger overpressures at greater then HE would provide
Requires little or no oxygen in the molecular structure therefore making a FAE explosion 3 to 5 times hotter then HE
In your own words explain the definition of blast?
A blast comes from a explosion
From the explosion gas and heat is produced
A shock wave comes from the centre of the explosion
What is the formula used for the probability product rate?
PK =PH X PR X PL
List 3 levels of damage which an ammo designer may wish to achieve in regards to target analysis?
Destruction
Neutralisation
Disablement
On the battlefield, people appear as many different targets. What factors affect their vulnerability and explain each of them?
Body armour, helmet PPE- if the personnel have body armour on or the type and what parts it covers.
The available cover- is the cover in the area that can be used for protection
Attitude- their presented area
What are the two energy sources employed in ammunition design. Briefly describe each below?
Kinetic energy- uses a solid shot which dissipates energy on impact to create penetration
Chemical energy- uses a chemical substance with a high V of D to create a shock wave or over pressure
Over pressure from a chemical energy source (blast) is one of the four basic techniques used in the attack of aircraft in flight. What are the other 3?
Fragmentation
Blast and fragmentation
Special kinetic energy missiles
Standard criteria for aircraft damage?
Kk-kill target immediate destruction
K-kill target destroyed in 10 secs
A-kill target destroyed in 5 mins
B-kill target disabled with in 5 hours
C-kill target abandons mission (mission abort)
E-kill target completes mission however requires maintenance before next flight
Effect does altitude have on a blast warhead?
Density
Attenuation
Miss distance
Altitude increases/warhead increases
Cluster disc warheads are one type of attack available in the engagement of aircraft in flight, name 3 others?
Blast
Fragmentation
Blast and fragmentation
What % of fragmentation in an anti aircraft warhead is wasted?
80%
How can a fragmentation warhead be made more efficient?
They can 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 ( preferential fragmentation)
7 Types of armour?
Rolled homogeneous armour Spaced homogeneous armour Face hardened Explosive reactive armour Ply Bar Composite
3 shot failures?
Barrelling
Shattering
Lateral stresses
Explain shattering?
Hardness of a steel shot makes it brittle
On impact hoop stresses are set up in the nose of the shot
At high striking velocities the shot nose can fall under stresses and longitudinal cracks are formed
Explain barrelling?
Direct compression failure in the shot material. The shot bellies at about mid point
Increase in cross sectional area and the shot fails to push through
Improved strength by a hardness gradient along the shot
Shot hardest at its tip and is soft at base
Explain lateral bending?
At high angles of attack the shot is subjected to serve lateral stresses particularly its rear end
Reduced by increasing the toughness towards the rear end by fitting a toughened steel sheath over the rear end
What is F-kill?
Fire power kill is disablement of the ordnance, crew or explosive ordnance of the target
Types of behind armour effects?
Spalling Illumination Heat Over pressure Fire
In a combined kinetic/chemical energy attack, what problem arises in relation to the chemical energy portion of the round?
That the initiating device can with stand the initial forces of impact
Ways of increasing penetration?
Lengthening of barrel Rocket assistance Improve steadiness of shot Lengthen the projectile Use of segmented long rod penetrators
Severity of a casualty or wound type is dependent on what 3 factors WRT energy transfer?
Tumbling/yawning reduce energy transfer
Rate of transfer of energy from projectile to target
The actual amount of energy transferred
The actual amount of energy transferred
The ammunition designer can control the size of fragments obtained from a shell body by varying what design features?
The position of the fill in relation to the fragmentation
Wall thickness
The velocity of detonation of the main charge
The fragmentation material type
A designer can control fragment velocity by varying what?
Amount of explosive behind wall and its V of D
The charge density and V of D
The density of the wall material
Explain how HESH works?
The high explosive explosion on the armour plate creates a shock wave into the plate
The shock waves travel through the armour plate till it reaches the air pocket where the change in medium reflects the wave
The reflected shock waves tension stress over stresses the armour in the area of the rear face
What is the point of initiation of HESH?
Base detonation
What is reverse impact detonation?
Where the detonation occurs before the fuse has detonated the main fill. This will cause the blast to travel in the wrong direction
In regards to external ballistics, how is air resistance reduced when designing a kinetic energy round?
High mass
High velocity
Aerodynamic design
Snail cross sectional area
How to reduce spin on APFSDS?
Slipping band/ring to negate the effects of any rifling
What forces are utilised to assist with discarding the sabot?
Residual gas pressure from firing
The momentum through the air will use the air resistance to remove the sabot
Ratios applied to forms of fin stabilisation?
Spin- 7:1
Fin-15:1
Factors that affect performance of a shapes charge?
Cone diameter Shape of liner Liner material Stand off distance Rate of spin Uniformity of the fill
Peak performance stand off distance of shape charge?
5 cone diameters
Plate charge penetration of at least one cone diameters can be achieved at what distance?
1000 CD’s
