Polymer nanocomposites for light armour applications

Lead Research Organisation: Loughborough University
Department Name: Sch of Mechanical and Manufacturing Eng

Abstract

Increasing terrorist activities and the involvement of UK troops in hostile overseas missions has greatly increased the exposure of our soldiers and police force to life threatening situations. A similar danger is also faced by aid workers and other civilian personnel working in hostile areas. The issue of combat survivability is of primary concern in such situations, with a need for high performance, lightweight and cost effective protection for personnel and vehicles. Performance requirements in these applications are highly demanding and protective materials must withstand many different threats, whilst maintaining performance integrity under harsh conditions. To address the challenge of these demanding requirements, new materials, construction methods and designs must be considered. Nanostructured polymeric materials, such as polyurethane nanocomposites for linings for vehicle armour, and ultra-high molecular weight polyethylene and its nanocomposites for light weight body armour, have great potential to improve the combat survivability of both vehicle and body armours, whilst reducing cost and weight. Recent research on polymer nanocomposites has indicated that a nanostructured material architecture can enhance a wide range of physical and engineering properties. Armour with polyurethane (PU) based linings is currently being considered for armed vehicles. Initial research has indicated that a polymer lining can significantly improve the damage resistance of steel armour. For personnel protection, a balance must be made between the needs of high protection and light weight. Ultra-high molecular weight polyethylene (UHMWPE) and its nanocomposites have the potential to raise the effectiveness of protection for troops with the minimal possible weight. The success of using PU nanocomposites for the interior of armed vehicles and UHMWPE and its nanocomposites for body armour will depend on their performance at high strain rates. To date, the only reports in this field for polycarbonate nanocomposites have been on the limited work conducted by the US army. In order to design, predict and optimise the performance of armour under ballistic impact, a detailed knowledge of material behaviour, a material constitutive model that is accurate under the applied time dependent stress fields and an understanding of high rate dynamic modelling, shock wave behaviour, fracture and energy dissipation is needed. Experimental characterisation and modelling of such behaviour is highly challenging, however, recent advances in high rate test equipment, dynamic modelling and the ability to incorporate complex material behaviour into multi-physics finite element models has greatly increased the accuracy and reliability with which this can be done. This project proposes to explore the potential of polymer nanocomposites for light armour applications. Specifically, UHWPE nanocomposites will be investigated for improved lightweight body armour and PU nanocomposites will be investigated for armour linings for armed vehicles. PU based materials are currently of great interest for the interior lining of armed vehicles, to increase the rupture resistance of steel hulls and prevent metal fragments from wounding or killing vehicle occupants. Improved UHMWPE based materials are also urgently required, to provide high damage resistance allied with the lightweight and flexibility that enable the wearer to operate at optimum efficiency. The proposal is aligned with the MoD Defence Technology Strategy. The novelty in this proposal arises from the materials to be developed, the unique high rate characterisation methods and the novel computational methods to be developed. It is also novel in that the proposal aims to combine the expertise of a multidisciplinary team to produce a complete and holistic solution.

Publications

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Alghamdi A (2017) Nanoparticle type effects on the scratch resistance of polyethylene-based nanocomposites in International Journal of ADVANCED AND APPLIED SCIENCES

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Alghamdi A (2014) Creep Resistance of Novel Polyethylene/Carbon Black Nanocomposites in International Journal of Materials Science and Engineering

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Alghamdi A (2015) High temperature effects on the nanoindentation behaviour of polyethylene-based nanocomposites in International Journal of Computational Methods and Experimental Measurements

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Cai D (2014) High mechanical performance polyurea/organoclay nanocomposites in Composites Science and Technology

Related Projects

Project Reference Relationship Related To Start End Award Value
EP/G042756/1 01/11/2009 30/06/2012 £657,839
EP/G042756/2 Transfer EP/G042756/1 01/07/2012 31/10/2013 £197,563
 
Description Methods for the dispersion of carbon nanotubes, carbon black and clay in polyethylene, polyurethane and polyurea have been developed.

A series of modified polymers have been developed, where control of polymer, blend, processing conditions and nanofiller can be used to tailor specific properties.

The performance of the materials under various conditions, including high strain rates, wear and impact, have been characterised and this has been related to microstructure.

Key material characteristics for enhancing the impact perforation resistance of ductile polymer plates have been identified.

Methods of modelling the performance of multi-layer armour systems including polymer layers have been demonstrated.

Mechanisms have been identified for enhancing the ballistic limit of metallic targets using a polymer layer.
Exploitation Route Materials and processing industries, as well as end-users, will be interested in the materials and processing methods developed in the project.

The methods developed will be used in our future research and to produce high performance polymer based nanocomposites with improved electrical, mechanical and barrier properties.

The analysis and modelling methods developed in the project, as well as the understanding of impact performance of multi-layer armour systems, are also being taken forward into future research.
Sectors Aerospace, Defence and Marine,Agriculture, Food and Drink,Manufacturing, including Industrial Biotechology,Transport

 
Description The dispersion of nanofillers in polymer matrices without the use of solvents is still a challenge in the processing of polymer nanocomposites. The method developed in this project for the dispersion of nanofillers such as carbon nanotubes, exfoliated clay and carbon black, without the use of any solvent will provide a new route for the materials and processing industry. For example, polyolefins are widely used for packaging and the incorporation of clay into a polyolefin can improve the barrier properties (gas and water permeation). The barrier properties depend on the dispersion and exfoliation of the clay. In order to achieve good dispersion and exfoliation of the clay, solvents or chemical additives have been used in the past, however, it is clear that this technology cannot be accepted in the packaging industry. Our method overcomes this problem. Nanocomposite from the project are also awaiting testing by DSTL at Porton Down as a continuation of their initial application aim in lightweight armour. Here it is hoped that the good impact performance with tailored properties, such as increased creep and wear resistance may be beneficial to certain applications requiring both impact absorption and structural integrity. The method can also be used in the preparation of graphene based nanocomposites, with a wide potential range of applications.
First Year Of Impact 2014
Sector Aerospace, Defence and Marine,Agriculture, Food and Drink
Impact Types Economic

 
Description Collaboration with DSTL 
Organisation Defence Science & Technology Laboratory (DSTL)
Country United Kingdom 
Sector Public 
PI Contribution The results of research carried out in the project have been presented at a number of DSTL events and materials have been supplied for testing.
Collaborator Contribution The project was half funded by the MOD under the JARPD scheme. DSTL also provided technical input to the project and has planned to test materials developed within project
Impact A joint journal paper has been published.
Start Year 2009
 
Description Collaboration with Line-X 
Organisation Line-X
Country United Kingdom 
Sector Private 
PI Contribution Nanofillers were incorporated into materials supplied by Line-x in an attempt to improve their protective properties
Collaborator Contribution Line-X supplied polyurethane and polyurea materials and manufactured both unmodified and nano-modified samples for testing.
Impact Materials supplied by Line-x were characterised at high strain rates. The nano-modification resulted in significant property improvement under static loading conditions but not under impact conditions.
Start Year 2010
 
Description Collaboration with Universidad de los Andes 
Organisation University of the Andes, Chile
Country Chile 
Sector Academic/University 
PI Contribution The Univesrity of Nottingham hosted a visit by a PhD student from the Universidad de los Andes and provided data from high strain rate tests for the simulation work.
Collaborator Contribution The visiting student developed an inverse FEA method of generating high strain rate material properties from a single Split Hopkinson Pressure Bar test. These properties are useful for characterising the dynamic properties of a material and as input data for impact simulations.
Impact The work was presented at the Fracture and Damage Mechanics conference in 2013 and a journal paper is being written.
Start Year 2011
 
Description Dr Manmohan Singh Scholarship Fund (PhD student Kedar Pandya) 
Organisation University of Cambridge
Department Dr Manmohan Singh Scholarship
Country United Kingdom 
Sector Academic/University 
PI Contribution Supervision to PhD research by Graham McShane and Bill Stronge
Collaborator Contribution Continuation of the research of Iman Mohagheghian, carrying out further research on the numerical modelling of the impact perforation of multilayer targets, and extend the range of materials investigated to include epoxy nanocomposites for impact resistant fibre reinforced composites.
Impact None to date
Start Year 2013
 
Description 2nd International Conference of Nano and Materials Engineering 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact Share information and stimulate discussion
Year(s) Of Engagement Activity 2014
URL http://www.ijmse.net
 
Description 6th Int Conf Comp Methods and Experiments in Materials Characterization 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact A paper was presented at the conference title: 'Mechanical characterisation of novel polyethylene nanocomposites by nanoindentation'.

The conference confirmed the applicability of characterization methods used in the project and the interpretation of results
Year(s) Of Engagement Activity 2013
URL http://www.witpress.com/books/978-1-84564-720-9
 
Description Centre for Defence Enterprise (CDE) Showcase Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The project presented a stand at the Centre for Defence Enterprise Showcase event in London on the 27th March 2012. A flyer, poster, rolling video presentation and samples were produced for the event. This stand was visited by industrialists, academics and government workers, including the Minister for Defence Equipment, Support and Technology, Peter Luff.

The event enabled researchers to interact with a wide range of industrialists and government workers who they would not usually meet and enabled them to describe their work to a government minister.
Year(s) Of Engagement Activity 2012
URL http://www.youtube.com/watch?v=7JZudblFIAc
 
Description DSTL Presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact The project results were presented to scientists and project leaders at DSTL Porton Down with an interest in the use of polymers in armour systems

Further talks on the application of the materials developed and testing of materials at DSTL have been arranged
Year(s) Of Engagement Activity 2012
 
Description DSTL Research Showcase Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A poster was presented as part of an event at DSTL Porton Down showcasing their externally funded research. This provided an opportunity for discussions with DSTL staff and other external research contractors.

Members of the projects were invited to participate in an international high strain rate test programme.
Year(s) Of Engagement Activity 2011
 
Description FDM X 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact A paper was presented at the conference titled 'Polymer nanocomposites (NCs) for armour applications'

Discussions at the conference impacted consideration of the role of particle agglomerates in nanocomposites and how this may be modelled.
Year(s) Of Engagement Activity 2011
 
Description FDMXII 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact A paper was presented at the conference 'Thermo-mechanical investigation of polyethylene blends and nanocomposites for high strain rate applications'.

Discussions at the conference impacted consideration of the modelling of failure in nanocomposites
Year(s) Of Engagement Activity 2013
 
Description ICM 2011 Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact A paper was presented at the conference titled: 'Penetration and perforation of nano-filled polymer plates.'

Discussions at the conference supported the interpretation of the experimental results.
Year(s) Of Engagement Activity 2011
 
Description ISIE 2013 Conference 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Two papers were presented at the conference titled; 'The effect of indenter nose-shape on the perforation of polymer-metal bi-layer plates' and 'Quasi-static and impact perforation of polymer-metal bi-layers with a blunt projectile'

Discussions at conference impacted strategies for modelling the perforation of laminated targets.
Year(s) Of Engagement Activity 2013
 
Description Line-X presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A presentation on the project was delivered followed by discussion of Line-X materials and processes.

Line-x agreed to supply materials for modification
Year(s) Of Engagement Activity 2011
 
Description MPSVA 2012 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Other academic audiences (collaborators, peers etc.)
Results and Impact Two papers were presented at the conference titled; 'Finite element analysis of the high strain rate testing of polymer nanocomposites' and 'Impact response of polymer-metal laminates'.

Discussions at the conference impacted consideration of the modelling of the effect of nanofillers and friction on heat generation at high strain rates, and the interpretation of experimental measurements of the impact response of layered targets.
Year(s) Of Engagement Activity 2012
 
Description Permali Presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Professional Practitioners
Results and Impact A presentation was delivered, followed by discussion with scientists and project leaders at Permali interested in the application of advanced polymers in armour systems

Discussion of testing of materials developed in the project by Permali are ongoing
Year(s) Of Engagement Activity 2012