High Performance Ductile Composite Technology (HiPerDuCT)

Lead Research Organisation: University of Bristol
Department Name: Aerospace Engineering

Abstract

Conventional composites such as carbon fibre reinforced plastics have outstanding mechanical properties: high strength and stiffness, low weight, and low susceptibility to fatigue and corrosion. Composites are truly the materials of the future, their properties can be tailored to particular applications and capabilities for sensing, changing shape or self healing can also be included. Their use is rising exponentially, continuing to replace or augment traditional materials. A key example is the construction of new large aircraft, such as the Boeing 787 and Airbus A350, mainly from carbon fibre composites. At the same time, there is rapid expansion of composite use in applications such as wind turbine blades, sporting goods and civil engineering infrastructure.Despite this progress, a fundamental and as yet unresolved limitation of current composites is their inherent brittleness. Failure is usually sudden and catastrophic, with little or no warning or capacity to carry load afterwards. A related problem is their susceptibility to impact damage, which can drastically reduce the strength, without any visible warning. Structures that look fine can fail suddenly at loads much lower than expected. As a result complex maintenance procedures are required and a significantly greater safety margin than for other materials. Our vision is to create a paradigm shift by realising a new generation of high performance composites that overcome the key limitation of conventional composites: their inherent lack of ductility. We will design, manufacture and evaluate a range of composite systems with the ability to fail gradually, undergoing large deformations whilst still carrying load. Energy will be absorbed by ductile or pseudo-ductile response, analogous to yielding in metals, with strength and stiffness maintained, and clear evidence of damage. This will eliminate the need for very low design strains to cater for barely visible impact damage, providing a step change in composite performance, as well as overcoming the intrinsic brittleness that is a major barrier to their wider adoption. These materials will provide greater reliability and safety, together with reduced design and maintenance requirements, and longer service life. True ductility will allow new manufacturing methods, such as press forming, that offer high volumes and greater flexibility.To achieve such an ambitious outcome will require a concerted effort to develop new composite constituents and exploit novel architectures. The programme will scope, prioritise, develop, and combine these approaches, to achieve High Performance Ductile Composite Technology (HiPerDuCT).

Planned Impact

This highly ambitious, multi-disciplinary, and innovative programme is designed to move polymer composite structures in a fundamentally new direction. The goal is not only to improve performance and reduce cost, but crucially to introduce composites to a wide range of new applications, where use is currently limited by design complexity, processing challenges, ultimate failure mechanism, or maintenance demands. Relevant sectors include, aerospace, offshore, renewables, and high performance sports, but will extend to consumer goods, conventional automotive and other ground transport, civil engineering and the chemical industry. A range of stakeholders will benefit: Companies working in the composites field, either supplying materials or using them to manufacture structures, will gain access to new technology, either through directly licensing intellectual property developed during the programme, or through subsequent co-development projects. Technology transfer will be facilitated by specialist teams at Imperial (Innovations Ltd) and Bristol (Research & Enterprise Development), who have extensive experience in balancing the need to protect inventions while encouraging commercial exploitation. Industrial partners will thus gain new capabilities allowing them to develop new products, leading to a competitive advantage, and ultimately, UK wealth creation. The UK is home to a number of major composites companies, who maintain their world-leading position, by embracing opportunities for innovation. Several such companies will play an active role in the programme grant, helping to build a UK research network in the emerging field of ductile composites. This grouping will foster future collaborations, encouraging UK R&D efforts, as well as attracting inward international investment. In addition, there are a variety of manufacturing companies, for example, in civil engineering, the automotive and consumer goods sectors, who do not routinely use composites. The simpler processing and service requirements of HiPerDuCT, will provide a fundamentally new materials opportunity; the UK's internationally-recognised industrial design community will thus acquire a new capability to create further innovative products. At the same time, the extended use of composite materials will engage fresh academic interest, in fields ranging from chemistry to mechanical engineering, that will support the uptake and development of new designs and applications. More generally, society will benefit from the emergence of HiPerDuCT that provide improved performance, safety, & environmental sustainability in a variety of contexts. Ductile composites intrinsically improve safety by avoiding catastrophic failure, and minimising inspection requirements. The associated weight reduction will offer improved fuel efficiency or range in transport applications, while wind turbines will be more structurally efficient and benefit from reduced maintenance requirements, particularly offshore. By simplifying processing and improving lifetime, HiPerDuCT will offer reduced waste; some embodiments may enable direct recycling or reuse, a long-term composite goal. Through commercialisation activities, the academic institutions will benefit from additional revenue that they invest to bring forward other new technologies, through Imperial Innovations and Bristol RED. Composite materials are a high profile and widely monitored technology. With the success of the project, the UK will be making a clear and valuable contribution to their global implementation, which will enhance our reputation in the area, and help to attract both further investment and interactions with world-leading organisations and individuals. The program is aligned with stated UK objectives to realign the economy towards advanced manufacturing. It provides an opportunity to highlight the contribution of Science and Engineering towards these goals, both with the public and within government.
 
Description Composites have become established as very high performance materials and continue to expand rapidly into new markets and applications. However a fundamental limitation of current composites is their inherent brittleness. Failure is usually sudden and catastrophic, with little warning or residual load carrying capacity. Therefore the aims of HiPerDuCT are to design, manufacture and evaluate a range of composite systems with a ductile or pseudo-ductile response, while maintaining the strength and stiffness for which composites are so highly prized.

The programme has investigated the different potential mechanisms identified for creating more gradual failure and successfully demonstrated pseudo-ductility in all of them. A key measure used to assess progress is pseudo-ductile strain, defined as the difference between the final failure strain, and the elastic strain at the same stress. Research has focussed on tensile loading, primarily of unidirectional materials. Key results so far include:

- Thin carbon angle plies have been shown to rotate under load producing 1.5% pseudo-ductile strain without delaminating and a maximum stress of 936 MPa.

- Wavy ply sandwich composites have been created with up to 9% strain at the structural level and high energy absorption (patent submitted).

- Co-mingling of different fibre types has been achieved, giving a more gradual failure with 14% increase in maximum strain.

- A new mechanism of ply fragmentation has been demonstrated in thin ply hybrids, producing a non-linear stress-strain response with a plateau and pseudo-ductile strains of up to 2.7%.

- Model systems of discontinuous prepreg have shown the potential for additional strain via slip at the interfaces.

- A novel manufacturing process has been developed allowing high volume fraction highly aligned discontinuous fibre composites to be produced (patent submitted). These have shown record modulus and strength for single materials, approaching those of continuous fibre composites. Excellent potential for pseudo-ductility has been demonstrated based on the ability to achieve novel architectures with different fibre types, lengths and distributions. This technology is currently being investigated with a large carbon fibre recycling company.

- Good progress has been made towards creating ductile nanotube fibres that show high initial modulus and strains to failure of several hundred %.

- Considerable modelling of the mechanisms has been undertaken, giving a good understanding of the further developments necessary to achieve high performance ductile composites. In particular, strain hardening has been identified as a characteristic feature of the matrix required to ensure a stable ductile response and successful coupling between length scales.

- Two new mechanisms (both under consideration for patenting), and associated process technologies have been developed to introduce strain hardening behaviour during pull-out of fibre fragments.

- A patent has been submitted for a novel composite strain sensor which exploits material properties of a carbon/glass sandwich to give a visual indication of overload.

- A patent has been submitted for a new sizing concept that modifies the failure mode of carbon fibre composites, and increases their absolute tensile strength.
Exploitation Route Composites are increasingly being used in aerospace and other applications, such as automotive components, wind turbine blades, sporting goods and civil engineering.

Despite this progress, a fundamental limitation of current composites is their inherent brittleness. Failure is usually sudden and catastrophic, with little warning or residual load carrying capacity.

Whilst we are only half way through this programme, interesting results across the themes have been encouraging and suggest that highly performing ductile or pseudo-ductile composites can indeed be achieved. These could have applications in all the domains currently using high performing composites. Shorter term routes to exploiting specific aspects of the technology developed in HiPerDuCT include i) in the recycling of carbon fibre into higher added-value products, ii) in any application requiring a low-cost method of visually demonstrating that a component has been subject to an overload condition and iii) in safety critical applications of composites where more gradual failure may be beneficial, including aerospace, automotive and sporting goods.
Sectors Aerospace, Defence and Marine,Chemicals,Construction,Environment,Leisure Activities, including Sports, Recreation and Tourism,Manufacturing, including Industrial Biotechology,Transport
URL http://www.hiperduct.ac.uk/
 
Description As the project enters its final year, we have begun to focus our attention on those aspects of the research which have clear routes to exploitation. One example is a patent pending composite strain sensor that arose directly from HiPerDuCT. Although at early stages, we are actively engaged with five companies who are interested in exploiting this technology and hope to be able to licence the technology to a start-up company and others. We are also actively developing demonstrators of novel thin ply angle ply structures which we also expect to lead to interest from manufacturers A new sizing concept has also been developed that modifies the failure mode of carbon fibre composites, and increases their absolute tensile strength. The technology has been patented and will be promoted with relevant companies over the coming year Another technology that arose from HiPerDuCT that allows the alignment of short fibres is currently the subject of both an Impact Acceleration Account activity, further contract research with a large carbon fibre recycling company, as well as a further EPSRC grant.
First Year Of Impact 2011
Sector Environment,Manufacturing, including Industrial Biotechology,Other
Impact Types Economic
 
Description Building Global Engagements in Research
Amount £2,800 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 03/2013 
End 03/2013
 
Description EPSRC - High Performance Discontinuous Fibre Composites - a sustainable route to the next generation of composites
Amount £1,400,000 (GBP)
Funding ID EP/P027393/1 
Organisation University of Cambridge 
Department Engineering and Physical Sciences Research Council EPSRC
Sector Public
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 06/2017 
End 06/2020
 
Description EPSRC IAA Award - Composite Strain Sensor Market Search
Amount £15,000 (GBP)
Organisation University of Bristol 
Sector Academic/University
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 03/2016 
End 03/2017
 
Description EPSRC Impact Acceleration Account - ELG
Amount £15,000 (GBP)
Organisation Engineering and Physical Sciences Research Council (EPSRC) 
Sector Academic/University
Country United Kingdom of Great Britain & Northern Ireland (UK)
Start 01/2015 
End 07/2016
 
Title DIC Data - Meisam 
Description The underlying data presented in the paper "Energy dissipation during delamination in composite materials-An experimental assessment of the cohesive law and the stress-strain field ahead of a crack tip", by Meisam Jalalvand, Gergely Czél, Jonathan D Fuller, Michael R Wisnom, Luis P Canal, Carlos D González, Javier LLorca, Composites Science and Technology, includes: 1. X and Y Coordinates of the Digital Image Correlation facets. - Displacement of facets centre from Digital Image Correlation. - Shear strain distribution over the glass/epoxy and carbon/epoxy layers. - Shear stress distribution at the interface. - Separation at the interface. 
Type Of Material Database/Collection of data 
Provided To Others? No  
Impact N/A - only recently published 
URL https://data.bris.ac.uk/data/dataset/91unnvqibajq1kf7fhsat28yv
 
Description ELG collaboration 
Organisation ELG Carbon Fibre Ltd
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Private 
PI Contribution Using HiPerDIF machine to manufacture and test samples from recycled fibre to determine viability of the machine as a quality control device
Collaborator Contribution - Materials - Expertise/Knowledge
Impact - Increased knowledge of quality control process for recycled carbon fibre - Further development of our knowledge of machine characteristics - Further collaboration leading to potential industrial exploitation of the technology
Start Year 2015
 
Description HiPerDuCT Industrial Partners 
Organisation BAE Systems
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Private 
PI Contribution Presentations of latest results.
Collaborator Contribution Industrial partners attend Industry update meetings and contribute to the Advisory board which helps set future research direction.
Impact - Shaped direction of research - Supplied material - Contributed to workshops, meetings etc.
Start Year 2011
 
Description HiPerDuCT Industrial Partners 
Organisation Hexcel Composites Ltd
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Private 
PI Contribution Presentations of latest results.
Collaborator Contribution Industrial partners attend Industry update meetings and contribute to the Advisory board which helps set future research direction.
Impact - Shaped direction of research - Supplied material - Contributed to workshops, meetings etc.
Start Year 2011
 
Description HiPerDuCT Industrial Partners 
Organisation Rolls Royce Group Plc
Country United Kingdom of Great Britain & Northern Ireland (UK) 
Sector Private 
PI Contribution Presentations of latest results.
Collaborator Contribution Industrial partners attend Industry update meetings and contribute to the Advisory board which helps set future research direction.
Impact - Shaped direction of research - Supplied material - Contributed to workshops, meetings etc.
Start Year 2011
 
Title Composite Material Suitable for a Morphing Skin 
Description A morphing skin for an air vehicle structure, the skin being formed by a composite material comprising: a multiplicity of fibres, a matrix incorporating the fibres, and a thermo-sensitive material such as a thermo-plastic. The thermo-sensitive material is reversibly transitionable in response to a change in temperature, between (i) an ambient temperature mode in which the thermo-sensitive material is capable of transferring loads in the composite material, and (ii) a heated mode in which the ability of the thermo-sensitive material to transfer the loads is reduced. This allows the stiffness of the skin to be temporarily reduced to enable the skin to be morphed into a different shape. 
IP Reference PCT/GB2013/050826 
Protection Patent application published
Year Protection Granted 2013
Licensed No
Impact -
 
Title Method and apparatus for aligning discontinuous fibres 
Description A new method has been developed to enable highly aligned discontinuous fibre composites to be manufactured. 
IP Reference GB1306762.4 
Protection Patent application published
Year Protection Granted 2013
Licensed No
Impact We are currently working with a large Carbon Fibre Recycling company to explore applications and scale-up of this technology. We have also successfully applied for further EPSRC funding, which we expect will help to generate further commercial opportunities for the technology.
 
Title Strain Overload Indication Device and Method for Manufacturing Thereof 
Description A Strain Overload Indication Device and Method for Manufacturing Thereof, consisting of a carbon/glass sandwich that can be applied onto (or incorporated into) any product (composite or otherwise) that would benefit from a low-cost lightweight method of visually indicating whether a pre-determined strain has been exceeded. 
IP Reference 1520988.5 
Protection Patent application published
Year Protection Granted 2015
Licensed Commercial In Confidence
Impact We are actively pursuing several routes that could produce significant impacts.
 
Title Visual Strain Overload Sensor 
Description Fragmenting hybrid laminates create a pseudo-ductile response and a striped pattern of fractures and delaminations which can be used as a simple visual strain overload sensor. This novel hybrid composite sensor may be used as an indicator patch co- cured with composite components or retrofitted/bonded onto the surface of composite or metal components, or be incorporated as an integral load-carrying surface layer with sensing functionality. Its advantages over conventional strain gauges include: - Very robust - Wireless and offline - Low cost - Lightweight - Requires no special training to read - Can be a whole surface layer, or applied as a patch 
Type Of Technology New/Improved Technique/Technology 
Year Produced 2015 
Impact We are currently actively exploring commercialisation options with a range of organisations in a number of different domains for this patent-pending technology. 
 
Description Advanced Engineering Show 2016 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Attendance at the Advanced Engineering Show, Birmingham, November 2016.

We used the opportunity to showcase a HiPerDuCT output, in the form of the novel strain overload sensor, which we demonstrated on a bicycle handlebar.
Year(s) Of Engagement Activity 2016
URL http://www.easyfairs.com/events_216/advanced-engineering-2016_83352/advanced-engineering-2016_84103/
 
Description Advisory Board meetings 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Annual meeting of HiPerDuCT Advisory board including Industrial and academic members. Purpose is to discuss findings and future research direction and allow participants to shape future direction.
Year(s) Of Engagement Activity 2012,2013,2014,2015
 
Description Composites in Sport conference 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Professional Practitioners
Results and Impact We presented the project and selected outcomes and their application in sporting goods.
Year(s) Of Engagement Activity 2016
URL http://compositesinsport.com
 
Description Cyclitech Conference presentation 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact Cyclitech was the first international conference on bicycle technology and attacted a large number of participants from the bicycle industry including manufacturers and resellers. We presented several aspects of HiPerDuCT technology to this new audience.
Year(s) Of Engagement Activity 2015
URL https://www.eiseverywhere.com/ehome/137476
 
Description HiPerDuCT Industrial Engagement Day 2015 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact An industrial engagement day saw c. 50 participants from a range of sectors come together at the National Composites Centre to learn about the HiPerDuCT Programme's latest results and participate in a workshop session to help shape future research directions

Presentations covering selected aspects of the programme:
- Pseudo-ductility of thin ply angle-ply laminates - Dr Jonathan Fuller
- Pseudo-ductile hybrid composites - Dr Gergely Czel
- HiPerDiF manufacturing method: from ductile hybrids to recycled short fibre composites - Dr HaNa Yu
- Wavy-ply sandwich structure for large deformations and energy absorption - Prof. Paul Robinson

Workshop session covering the following questions:
- What current composite designs or features would benefit from ductility?
- Which aspects of the HiPerDuCT programme would be of most interest?
- What applications look promising?
- What needs to be done to make this work for you?
Year(s) Of Engagement Activity 2015
 
Description Industry update meetings 
Form Of Engagement Activity A formal working group, expert panel or dialogue
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Meeting of HiPerDuCT Industrial partners. Purpose is to discuss findings and future research direction and allow participants to shape future direction.
Year(s) Of Engagement Activity 2012,2013,2014,2015,2016
 
Description Participation in JEC Composites Trade Show 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Industry/Business
Results and Impact The University of Bristol have a presence at JEC, the world's largest composite materials trade show, held in Paris, France 14-16th March 2017. On our stand on the Department for International Trade UK Pavilion, we are showcasing two of the project outputs - the novel composite strain overload sensor, and the HiPerDiF short-fibre alignment technology (both patent-pending).
Year(s) Of Engagement Activity 2017
URL http://www.jeccomposites.com/events/jec-world-2017
 
Description Visit to Airbus, Bristol, UK 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Industry/Business
Results and Impact Visit to Airbus with fellow PhD students to showcase PhD work to senior employees and Aerospace Engineering experts. The event was one of a series of industrial visits co-ordinated by the ACCIS CDT as part of the EPSRC's Impact Acceleration Account Scheme, which aims to widen participation in business engagement and knowledge exchange.

Ian Lane, Senior Airbus Expert and Visiting Industrial Professor in the Faculty of Engineering, reported that bringing Airbus experts and the University of Bristol team together for an open interactive discussion was a great way to meet the real people behind the research work and the facilitated an atmosphere of creative exchange.
Year(s) Of Engagement Activity 2015
URL https://www.youtube.com/watch?v=M-uLoUh8nk8&list=PLhlRlu-kcTox-ylt0QsNB0nCcOtPIHN6z&index=7
 
Description Website 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach International
Primary Audience Public/other audiences
Results and Impact We have redesigned the project website, and created specific resources for both general public and specialist audiences.

The general section of the website includes videos giving an introduction to composite materials. The specialist area of the website details key findings, publications and applications, as well as an interactive material parameters graph, showcasing how HiPerDuCT-developed materials compare to existing composite and metallic materials.
Year(s) Of Engagement Activity 2015,2016,2017
URL http://hiperduct.ac.uk