Self-Tuning Fibre-Reinforced Polymer Adaptive Nanocomposite (STRAINcomp)

The UK ENGINEERING AND PHYSICAL SCIENCES RESEARCH COUNCIL funded project

Smart self-sensing adhesive for hybrid joining applications

Use of carbon nanotubes (CNTs) in polymeric matrices has had increasing interesets among scientific and industrial communities for multi-functional applications. The CNTs can enable various characteristics of everyday materials, e.g. via enabling piezo-resistivity in structural applications. In the present research, CNTs are introduced to fastenerless adhesively bonded joints for enabling in-situ sensing of deformation in order to accurately interpret the onset and propagation stages of damage in the adhesive (cohesion and adhesion damage). Multi-walled CNTs (MWCNTs) has been utilised for mechanical strain and damage sensing of epoxy adhesives in adhesively bonded single-lap aluminium-to-aluminium joints, resulting from the MWCNT’s piezo-resistivity. The CNT modified bonded joints and the CNT modified epoxy adhesive have both been individually tested under monothonic static and cyclic tensile loads until the ultimate failure of the epoxy adhesive bond, and the changes in electrical resistance of the MWCNT modified adhesive have been monitored in situ. A novel interpretation method has been developed for estimation of microstructural adhesion damage in bonded joints from the electrical resistivity.The results indicate that the in-situ electrical resistance change as result of deformation and damage (bulk and interface) correlates with the applied mechanical load throughout the loading range from elasticity regime up to the bond’s ultimate failure point at both monothonic and cyclic loads. Correlation of the changes with the analytically calculated joint’s stiffness also suggests the adhesive’s ability in detection of initiation and propagation of damage in MWCNT modified bonded joints.Such repeatable indication suggests a process-enabling real-time strain measurement system in which a joint structure would not need additional sensors (e.g. piezo-sensors) for structural health monitoring.

Impact
  • STRAINcomp Academic & Industrial Impact

    The technology proposed by STRAINcomp will be applicable to a variety of research communities, scientists, educators, students and composite industries from the highly conservative aviation to automotive and renewable energy sectors as well as biomedical sector. STRAINcomp will also have indirect impacts on reductions in energy consumption and greenhouse gas emissions during the manufacturing process through the use of less carbon fibres, or microwave and radiofrequency rapid heating technologies. Developed in-situ measurement and strain sensor technologies via dielectric constant measurements can also be influenced post-project. That can open up opportunities for non-destructive dielectric measurement of defects in structure.
    The major impact of this project will be to inform development practice by improving the scientific understanding of microtoughening mechanism in the presence of nanomaterials so as to provide researchers, designers and manufacturers with the confidence to invest in this multi-disciplinary efficient technology and thereby improve materials and structures sustainability.
    By providing the evidence base for cost-effective lightweight technologies, STRAINcomp can stretch further towards low income companies as well as critical highly certification driven sectors such as aerospace and defence, and towards other multifunctional sectors such as biomedical devices, and/or communities will be able to afford to invest in improving their own multifunctional products, and realise the benefits.
    It is estimated that due to the multi-disciplinary nature of STRAINcomp the ultimate result is that almost all composite sectors will be benefited. This will make highly competitive composite market and will lead to cheap products so public will directly be benefited, but the impact on the environment and energy consumption will be minimal.

About STRAINcomp

What is STRAINcomp

In situ 3D X-ray CT nano-indentation of nanocomposites
In situ 3D X-ray CT nano-indentation of nanocomposites
In situ 3D X-ray CT nano-indentation of nanocomposites

Self-Tuning Fibre-Reinforced Polymer Adaptive Nanocomposite (STRAINcomp) is a UK EPSRC funded research (principal investigator: Dr. Hamed Yazdani Nezhad, Cranfield University,UK) will provide a state-of-the-art, swift, reversible and process-efficient material and technology in response to varying operating loads, an innovative scientific answer to the rate dependence challenge with a novel integrated material development. It proposes ‘one small step towards a giant leap’ for development of smart critical structures equipped with self-regulate micro-mechanisms. STRAINcomp is inherently multidisciplinary, and directly targets novel, innovative and disruptive technology of self-tuning high performance composite material for UK and global composites sectors.

The team
Internal (Cranfield)
Dr. Hamed Yazdani Nezhad
Principal Investigator, Associate Professor in Aerospace Structures, City University of London, UK
External (Collaborators)
Dr. Vijay Kumar
Professor in New Products from Biomass, Scotland's Rural College, UK
External (Collaborators)
Dr. Saurav Goel
Associate Professor, London South Bank University, UK
External (Collaborators)
Dr. Andrei shishkin
Collaborator, Institute of General Chemical Engineering, Faculty of Materials Science and Applied Chemistry, Latvia
External (Collaborators)
Dr. Hamed Attariani
Associate Professor, Wright State University, USA
Internal (Cranfield)
Dr. Meng-Fang Lin
Post-doctoral Researcher
Internal (Cranfield)
Danning Li
PhD in STRAINcomp
Internal (Cranfield)
Donglan An
PhD in STRAINcomp
Internal (Cranfield)
Raghvendra Kumar Mishra
PhD in STRAINcomp
External (Collaborators)
Ehsan Tanhaee
Candidate in molecular dynamic simulation
Internal (Cranfield)
Luis Lopez Lazaro
MSc in STRAINcomp
External (Collaborators)
Dr. Ata Yoosefinejad, MunroTechnology Ltd.
Industrial partner
External (Collaborators)
Dr. Terence Warmbier, Oxford Advanced Surfaces
Industrial partner
Hamed is an associate professor (senior lecturer) in Aerospace Structures in Aerospace Research Centre at City, University of London, and a visiting lecturer in Composite Engineering at the Enhanced Composites and Structures Centre in School of Aerospace, Transport and Manufacturing at Cranfield University. He is the principal investigator of the UK EPSRC First Grant project on 'Self-Tuning Fibre-Reinforced Polymer Adaptive Nanocomposite (STRAINcomp)', Ref. EP/R016828/1.
Dr. Hamed Yazdani Nezhad
Associate Professor in Aerospace Structures
Cranfield's Enhanced Composites & Structures Centre

With its advanced design and manufacturing capability, the pioneering Enhanced Composites and Structures Centre is an established partner to manufacturers and the members of their supply chains through short courses, consultancy and research. The Centre investigates and develops materials and processing technology for lightweight and efficient structures and combines an expertise in low cost manufacturing with modelling, simulation and structural health monitoring technologies. Its research into the development and processing of carbon fibre multi-axial fabrics is now part of the Airbus A380. The Centre has also produced a complete unmanned aircraft airframe using low-cost composite manufacturing; composite reinforcing techniques for aerospace landing gear; sensors for built-in detection of structural degradation ; and a cost model for composite design and manufacturing. The team designed and manufactured a successful experimental aircraft airframe, and an ultralight carbon fibre body for the Nissan UK hybrid supercar demonstrated at the Goodwood Festival of Speed.

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