Advanced Composite Materials & Technologies for Defence

1. ADVANCED COMPOSITE MATERIALS &
TECHNOLOGIES FOR DEFENCE
By 1)SUNIL RATHOD MM15M12
2)MANGESH SHINDE MM15MO8
3)MAYUR CHAVAN MM15M11

2. COMPOSITES FOR ARMOUR
o Noval ceramic materials, composite materials and
steels- highlighted in the recent Defence Technology
Strategy - that address these issues.
o Novel materials approaches to improve the resistance of
materials to high rate mechanical loading, wear and
impact.
o Modelling of the response of materials to high rate
loading, including high rate materials property
development for the input to such models.
o Predicting and improving the high rate deformation
performance of polymer composite materials and
structures.

3. oSince energy absorption in composite primarily occurs due to elongation
and failure of fiber, fiber with high tensile strength and high strain to failue
are best candidates.
oIn addition high sonic velocity in the fibre (depends upon Elastic Modulus
&Density) can lead to enhanced ballistic performance due to its ability to
spread out energy to larger areas.
o A Ballistic figure of merit U for ballistic applications has been proposed where
COMPOSITES‐ FIBERS FOR BALLISTIC
ARMOUR
Future armour
Presently in Use
o Kevlar (Aramid fiber), S 2
Glass & Dyneema
(UHMPE) are already in
use for ballistic
applications
o Future armour may use
M5 fiber (PIPD) & SWCNT
(single wall carbon nano
tube) fibers 10

4. COMPOSITES‐RESINS FOR BALLISTIC ARMOUR
oCompatible with fibers‐ Good Wetability
oModerate interface strength‐should allow de‐lamination and fiber
deformation
oHigh elongation to allow fibers to stretch to their limits
oFire and Water Resistance
oBoth thermo set and thermoplastic resins are being used
Thermosets
Phenolics,Epoxies
Thermoplastics
o‐Polypropylene(PP), Styrene‐isoprene‐styrene(SIS), Polyethylene (PE)
oHowever, as compared to fiber, effect of resin matrix is only marginal
11

5. DESIGN OF COMPOSITE ARMOUR FOR SOFT
PROJECTILES
(SMC, AK‐47 & SLR)
Core material in soft projectile: Lead antimony or mild steel
• Striking velocity: 390 – 830 m/s at 10 m distance
• Impact energy: 1000 J ‐ 3500 J
• Typical applications: BPJ, Helmet and VIP Vehicles
Material choice:
• Glass composites
• Aramid composites
• UHMWPE
composites
Decrease in
weight
Increase
in Cost
7.62 Lead & MS,
9mm Lead
Projectiles
13

6. ARMOUR
 Role of armour is protect a person , device or structure.
 Achieved by absorbing kinetic energy of projectile.
 Energy may dominantly be absorbed by plastic deformation and/or
fracture processes.
 Fragments as a result of fracture process should not cause
damage to what is being protected and should be arrested by
another layer at the back.
 Armour plate may have to fulfill two roles: a protective role and
structural role
 Both roles can be fulfilled by having sufficient strength at high
strain rate and appropriate thickness to provide both protection
and structural requirements of the Platform.

7. oProtection requirements are threat driven
oVery significant analysis is done to identify threat
probability and threat development under different
scenario.
oHowever, threats may be considered to be of some basic
fundamental types
oImpact:
Kinetic Energy, Chemical Energy (“Shaped Charge”)
oBlast:
o Mines (AP, AT, Influence), HESH
oCombined blast and impact
oSpecific weapons, entrained debris (Claymore
mines)
TECHNICAL REQUIREMENTS
4

8. Anti Tank Guided Munitions
Smart
Artillery
Unguided
Artillery
Bomblet
s
Unguided /
Guided
Mortars Terminally Guided
Sub Munition
Platform Threats
Mines
Rocket Propelled
Grenades
Tank kinetic energy
Guns
Tank chemical energy
Directed
Energy
Weapons
Chemica
l hazard
Radiologica
l and
nuclear
hazard
Improvised
Biohazard
Explosive
Devices
SOME THREATS
5

9. oDesirability of composite solutions for armour‐ better mobility
and transportability
oAbility of material to provide resistance to impact depends
upon
‐Hardness to blunt projectile
‐High strain to failure to absorb energy via a global
deformation process involving brittle fracture in ceramics
and composites or plastic deformation in metals.
oComposites rely primarily on brittle micro fracture
events to absorb energy. Ultimate energy absorption
is largely controlled by strain to failure of fibers.
oComposites are soft and are not effective against hard
projectiles However, when coupled with ceramics as
laminates, they provide effective solution
WHY COMPOSITES
6

10. BODY ARMOUR: PROBLEMS AND REQUIREMENTS
• Lightweight (now the body armour is 13 kg)
• Flexible wear and allowing mobility
• Low cost
• Stop projectile penetration
• Diffuse the impact energy to reduce behind armour blunt
trauma (BABT)

11. How it works
Hybrid
Sandwich
Structure

12. Outer layer: a laminate composite
structure to diffuse the energy of the
impact and to resist to deeper
penetrations
Armour substrate
Inner layer: auxetic foam
structure acting as small airbags
to protect the body from BABT
SCHEMATIC STRUCTURE
1mm
5 mm
10 mm

13. THE OUTER HIERARCHICAL COATING
• It is well-known that biological materials present optimized structure and
excellent mechanical properties.
• The challenge is to deposit a hierarchical hard and tough ceramic-metal
multilayered coating that mimics nature (e.g. nacre (mother of pearl),
mollusc shell and ancient fish armour).
• The initial coatings have been deposited by CVD (W3C and B13C2) and
PVD (Ti-V-Zr and Ti-V-Zr nitride):
• CVD is a high temperature process (1000ºC for B13C2) and therefore
just few substrate are compatible.
• PVD coatings can be deposited on CVD films but the opposite is not
always true – e.g. we experienced decomposition of the PVD films
in the atmosphere needed for CVD deposition.

14. NACRE (MOTHER OF PEARL)
• Nacre is a ceramic laminate composite made of aragonite tablet layers
separated by thin layers of an organic material (polymer).
• Nacre resists impact by dissipating the impact energy through nano and
micron cracks, plastic deformation and elastic responses.
Barthelat, et al. Experimental Mechanics 2007
Materials Research to Meet 21st Century
Defence Needs, 2003.

15. ANCIENT FISH ARMOUR
Each layer had a specific deformation and energy dissipation mechanism:
•The stiff outer layer transferred the energy of an applied load to the layers
below
•The stratified isopedine layer hinders deeper penetrations and prevents
catastrophic cracking through micro-cracking in the sub-layers.
Bruet et al.
Nature
Materials,
2008.
Young modulus and
hardness increase
(inside to outside of
the armour)

16. IMPROVED BALLISTIC PERFORMANCE OF
COATED PLATES
•The ballistic performance against a high velocity (> 350 m/s) impact 9 mm
bullet of aluminium alloy plates with and without 0.762 mm thick cobalt-
molybdenum-chromium or Zirconia plasma spray coatings.
• Penetration depth on the front face of the plate and the bulging on the
rear face of the plate were compared for plates with and without coatings.
• The coatings improved the
ballistic resistance of the plates
with an increase in non-
perforating projectile velocity
and a decrease in penetration
depth and bulging.

17. AUXETIC MATERIALS – WHAT ARE THEY ?
 Conventional materials have a positive Poisson’s ratio
 Auxetic materials have a negative Poisson’s ratio - grow fatter
when stretched
Poisson’s Ratio = _ Change in X
Change in Y

18. AUXETIC MATERIALS - BACKGROUND
 Auxetic materials have been known for approximately 100
years
 Field only started to be studied in 1987 by Rod Lakes
 The term auxetic was coined by Ken Evans - derived from
the Greek word auxetikos which means ‘that tends to
increase’
 Surge in interest since the late
1980’s

19. Conventional Foam Auxetic Foam
x5 x5
Alicona InfiniteFocus
optical 3D measurement device

20. Scanning Electron Microscopy (SEM)

21. AUXETIC MATERIALS – IMPORTANCE TO THE HIGH STRAIN
PROJECT
 Auxetic foam to act as ‘smart airbags’
 Act behind sandwich structure
 Auxetic materials are popular for their increase
in impact resistance and energy absorption:
- Reduce BABT
- Reduce / prevent backface signature
injury
Non-auxetic
Auxetic

22. FUTURISTIC MATERIALS‐ LET US AIM BIG
This tiny block of
transparent Aerogel
is supporting a brick
density
2.5 kg. The
is 0.1
weighing
aerogel's
g/cm3.
Carbon nanotubes
have numerous remarkable
physical properties including the
strongest sp2 bond, even
stronger than the sp3 bonds
that hold togetherdiamond
Fullerenes
can be
substantially
than diamond,
greater energy
made
stronger
but for
cost

23. 23/11
Advanced Technology
Development
Behind Armor Effects
Methodology
Casualty Reduction
Analysis Model
• New high performance polymers/
fibers/composites
• Nanotechnology
• Advanced ceramics & metals
• Enhanced predictive modeling
• Material systems integration
0.0
0.2
0.4
0.6
0.8
1.0
50 150 250 350 450 550 650 750
Acceleration (g's)
ProbabilityofInjury
Example Risk
Function
50% Injury
Risk at 270
g
(p = 0.05)
Conduct experimental (tissue
& test fixture), analytical and
numerical assessments of
non-penetrating impact on
body armor/body
Develop/update models
for armor system
performance from threat
definition to
incapacitation effect
Key Focus Areas
for Research and Development

24. THANK YOU
31

25. REFERENCES
 Army focused research team on functionally gradedarmor composites Ernest
S.C. Chin
 Defence Innovation in India The Fault Lines, Laxman Kumar Behera,Institute
for Defence Studies and Analyses, New Delhi.
o J P Agrawal Scientist Explosives Research & Development Laboratory Pune
Scientific Information 8r Documentation Centre (DESIDOC) Defence
Research & Development Organisation Ministry of Defence, Delhi-110 OM
o “Advances in healing on demands polymer and polymer composites”,Pengfei
Zhang,Guoqiang Li
Composites used in aero defence.