John Summerscales keynote and plenary presentations Lecture

Fibre distribution and the process-property dilemma.
(Characterisation of the mesostructure of woven fabric composites by fractal dimensions*.
Voronoi cells, fractal dimensions and fibre composites$).
For high-performance continuous fibre-reinforced (advanced) composites, as the fibre volume fraction increases, (a) the reduction of the pore space, and hence permeability of the reinforcement, makes long-range flow processes such as liquid composite moulding slower and (b) the mechanical properties increase. For real engineering structures, it is essential to balance this process-property dilemma by appropriate choice of the micro-/meso-structural features of the reinforcement architecture. This talk will review research which aims to understand the interrelationships between the factors above.
Keynote paper Sixth International Conference on Recent Advances in Composite Materials (ICRACM-2019) Swatantrata/Bhavan – INDIA 25-28 February 2019
Invited lecture Zhejiang University ~ Institute for Composites Science Innovation Hangzhou ~ CHINA 24 October 2017
Plenary presentation3rd China International Congress on Composite Materials (CCCM-3)Hangzhou ~ CHINA21-23 October 2017
Invited lectureStructural Integrity of Composite Materials and Structures* Isle of Capri ~ ITALY20-25 May 2001
Invited lecture5th International Conference on Microscopy of Composite Materials$Oxford2-4 April 2000
Durability of composites in the marine environment.PowerPoint
This paper will consider how to maintain the structural integrity of fibre-resin composites exposed to the marine environment. The composition of seawater changes with location due to eroded materials, and agricultural run-off, being carried to the sea from inland watercourses as well as being the natural environment for marine animals and plants. This salt water environment is corrosive to most engineering metals and, in combination with marine animals such as the naval shipworm (Teredo navalis), and gribble (Limnoriidae) causes rapid deterioration of wood. This paper will consider the durability of fibre reinforced plastics (FRP) in sea water and guide the reader towards appropriate materials selection to avoid degradation mechanisms which could compromise system performance.

This keynote speech will present an overview of the key considerations for the successful application of fibre reinforced polymer matrix composites in the marine environment.  For sonar domes, fibre-reinforced polymers provide a sensible balance of structural properties (stiffness and strength to resist hydrodynamic deformation) and acoustic properties (minimal attenuation of the sonar signal).  However, the performance of the sonar dome may be compromised by inappropriate materials selection or system design.  The glass transition temperature is a key design criterion.  Moisture will diffuse into polymers, but need not be a problem.  However, if soluble components are present in the laminate, then osmosis and the consequent blistering may occur.  Composites in turbulent flow may be susceptible to cavitation erosion.  Galvanic corrosion is not normally a problem for composites, but the combination of carbon fibres in contact with light alloys in the presence of seawater can lead to corrosion of the metal.

Plenary Lecture International Conference on Sonar Systems & Sensors (ICONS2018) Kochi (Kerala) - INDIA 22-24 February 2018
Invited lectureInternational Conference on Lightweight Design of Marine Structures (LIMAS 2015)Glasgow09-11 November 2015
Keynote Paper1st China International Congress on Composite Materials (CCCM-1)Beijing ~ CHINA10-13 September 2013
Plenary LectureIFREMER/ONR International Workshop on the Durability of Marine CompositesNANTES - France23-24 August 2012
Disposal of composite boats and other marine composites.PowerPoint
Fibre-reinforced monolithic composite materials and composite structures (angle-plied laminates and sandwich structures) find many uses in the marine environment. These applications include, but are not limited to, whole vessels and their various components, offshore and renewable energy systems, and marine leisure sports goods. The design of these structures is driven by low maintenance and extended lifetimes relative to the alternative materials. However, end-of-life composites do arise due to production waste, to new more efficient designs replacing older systems, and from accidental damage. This paper will review the options available for the avoidance of waste by appropriate design, manufacturing, marketing and maintenance through life. The standard waste hierarchy is Waste reduction > re-use > recovery > disposal. Various authors have reviewed the end-of-life options for composites waste. Rathje has divided recycling into four categories:
  • Primary: reprocessing waste to obtain product comparable to the original version,
  • Secondary: recovery of waste material with lower performance when compared to virgin materials,
  • Tertiary: decomposition of materials to recover monomers, feedstock materials or fuels,
  • Quaternary: recovery of the embedded energy in the materials.
The specific techniques for recovery of the component materials and/or energy are described in more detail and can be classified as:
  • solvolysis, including hydrolysis, methanolysis and solvothermal processes,
  • sub-, near- and super-critical fluids (albeit currently only available for small samples),
  • ionic liquids,
  • catalytic degradation,
  • acid digestion,
  • composting for bio-degradable materials,
  • pyrolysis, and
  • incineration
.The costs of separation and cleaning end-of-life composite components are still prohibitive on the small scale demanded by the rate of waste arisings. Hence, at present most scrap marine composites end up in landfill. However, as landfill costs soar and as more GRP boat hulls reach the end of their useful lives, alternative disposal routes will become more attractive. Recovery of the energy embedded in polymer composite matrix materials by incineration is still a field for further development. It would be timely to develop industrial scale composite recycling so that the composites industry as a whole can comply with legislation, and in order to prepare for the end-of-life of the increasing annual tonnage of composites produced. It would be appropriate to undertake cradle-to-grave (or preferably cradle-to-cradle) life cycle assessments of the various scenaria to understand which options will achieve the optimum balance of economic benefit without environmental burden.
Keynote paper2nd China International Congress on Composite Materials (CCCM-3)Zhenjiang ~ CHINA21-23 September 2015
The determination of the fibre volume fraction in natural fibre composites.PowerPoint
Recent EU directives (e.g., ELV andWEEE) have caused some rethinking of the life cycle implications of fibre reinforced polymer matrix composites. Man-made reinforcement fibres have significant ecological implications. One alternative is the use of natural fibres as reinforcements.The principal candidates are bast (plant stem) fibres with flax, hemp, and jute as the current front runners. Thework presented here will consider the characterisation of jute fibres and their composites. A novel technique is proposed for the measurement of fibre density.The new rule of mixtures, extended for noncircular cross-section natural fibres, is shown to provide a sensible estimate for the experimentally measured elastic modulus of the composite.
Invited lectureESF Exploratory Workshop on Environmentally Friendly Composites (EnviroComp)Coventry20-21 April 2004
Variability in, and property prediction for, natural fibre composites.PowerPoint
Keynote paper21st Anniversary Conference of the Bio-Environmental Polymer SocietyCoventry18-20 September 2013
A new rule of mixtures for natural fibre composites.PowerPoint
Experiments were conducted using a single batch of jute fibres. The coefficient of variation (CoV) in strain-to-failure was lower than the CoV for modulus or strength. This characteristic arises from the (incorrect) assumption of circular fibre cross-sectional area (CSA). Weibull statistics were used to compare the apparent CSA derived from the diameter measured by optical microscopy transverse to the fibre to the true CSA measured from sectioned fibres. The above ratio was then used as a fibre area correction factor (FACF) in the rules-of-mixture to generate improved prediction of the composite mechanical properties. Further analysis considers results from other research groups where sufficient data is available to make the comparison. The modified rules-of-mixture generally result in significantly better predicted values for both the moduli and strengths of the considered natural fibre reinforced polymer matrix composites
Keynote lecture5th International Conference on Innovative Natural Fibre Composites for Industrial ApplicationsRome ~ ITALY15-16 October 2015
Comparative life cycle assessment for natural vs glass fibre reinforcementsPowerPoint
The long term aim of this study is to carry out a comparative quantitative Life Cycle Assessment (QLCA) of natural fibres compared with glass fibres when used as reinforcement for polymer composites to confirm or refute the claim “green” fibres are the more sustainable option. As flax fibres are perhaps the most agro-chemical intensive bast fibres then, if flax is proven to be the better option, the other bast fibres (e.g., hemp or jute) may be shown to have even lower environmental burdens. Life Cycle Impact Assessment (LCIA) is used here to quantify the environmental impacts in the production process of converting flax fibres from plant stem to reinforcement for composite materials (cradle-to-gate). Life Cycle Inventory Analysis (LCI) for energy use has been completed using compiled data from a number of published sources. This paper reports on the LCIA considering environmental categories as listed in ISO/TR 14047:2003.
Plenary LectureAnglo-French days on Materials for Energy Efficiency in Transport (MEET) Paris - FRANCE 30 June – 01 July 2014
Allocation in the life cycle assessment (LCA) of flax fibres for the reinforcement of composites.PowerPoint
The ISO 14040 series of standards describe the principles and framework for the conduct of life cycle assessment (LCA). The system defines four phases: (i) definition of the goal and scope of the LCA, (ii) the life cycle inventory analysis (LCI), (iii) the life cycle impact assessment (LCIA), and (iv) the life cycle interpretation. The standards do not describe the LCA technique in detail, nor do they specify methodologies for the individual phases of the LCA. Dependent of the goal and scope, there can be very different outcomes from the analysis. This paper considers how the outcomes might change for the specific case of flax fibres for the reinforcement of composites. The study compares allocation of environmental burdens to two different primary products: (i) flax seed as a nutritional supplement with fibre generated from the waste stream, or (ii) flax fibre as the primary product.
Keynote lecture 6th International Conference on Innovative Natural Fibre Composites for Industrial Applications Rome ~ ITALY05-06 October 2017
The potential of composite materials in civil engineering applications.PowerPoint
Keynote paperCOBRAE Annual Members Meeting at the CIVILS 2008 ExhibitionLondon20 November 2008
Standards for Permeability.PowerPoint
Invited lecture 3rd NPL Industrial Advisory Group Meeting Composites, Adhesives and Polymers TeddingtonWednesday 10 June 2015

Created by John Summerscales on 10-Oct-2017 and updated on 30-Oct-2017 9:47. Terms and conditions. Errors and omissions. Corrections.