Advanced Composite Materials & Technologies for Defence
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This document discusses advanced composite materials and technologies for defense applications. It covers composites for armor applications, including novel ceramic materials and modeling of material response to high-rate loading. It discusses fibers and resins used in ballistic armor composites. Different threats are outlined and the technical requirements for armor are discussed. Body armor design considerations around weight, flexibility and cost are presented.
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)
- 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.