Dr David Fletcher

BEng, PhD

Dr David Fletcher

Senior Lecturer in Mechanical Engineering

Department of Mechanical Engineering
MezC11 Mappin Broad Lane
Mappin Street
Sheffield
S1 3JD
UK

Telephone: +44(0)114 22 27760
Fax: +44(0)114 2227890

email : d.i.fletcher@sheffield.ac.uk


Profile

Dr David Fletcher is a graduate of Leeds University where he studied Mechanical Engineering and worked with his sponsoring company CarnaudMetalbox Packaging. He was awarded a PhD in Mechanical Engineering from the University of Sheffield, and went on to conduct research in a range of areas including railway engineering, forming tool design and development of assistive tools for cataract surgery. From 2004 to 2009 he conducted research with Newcastle University focusing particularly on full scale railway engineering testing, before returning to Sheffield. He has been awarded several prizes for research in the railway area, including the prize for best paper addressing system interaction issues at the World Congress on Railway Research, Korea 2008, the Institution of Mechanical Engineers Railway Division, TA Steward-Dyer / F H Trevithick Prize, 2005, and the Institution of Mechanical Engineers Tribology Trust, Tribology Bronze Medal, 2000.

David is a member of the Leonardo Tribology Centre.

Areas of Research

Dr Fletcher's research interests are in engineering design and in performance of materials. The majority of his work has application in the railway sector, and combines experimental and modelling approaches. Major themes include:

Railway rail-wheel interface

The rail-wheel interface subjects the rail and wheel to extreme loading, often leading to high maintenance requirements. Dr Fletcher's research has developed new understanding of the interaction between rolling contact fatigue, surface crack initiation, crack growth and wear, linking these to the metallurgy of the steels involved. The research has combined experimental approaches including small and full scale trials to investigate crack growth, with modelling based on both fracture mechanics and contact energy, to understand and find solutions to the damage mechanisms involved.

Recent work has focused on adhesion at the rail-wheel contact, and development of new understanding of the creep-adhesion relationship. This is linked to earlier work on chemical approaches to prevention of low adhesion, and research into the performance of a range of lubricants and friction modifiers.

In 2009 Dr Fletcher revisited the Japanese Railway Technical Research Institute (RTRI), Tokyo, to continue a collaboration begun in 2006 on modelling crack growth in rail steel. This was originally supported through a short fellowship undertaken at RTRI funded by the Japan Society for the Promotion of Science.

Tribology

Research on the rail-wheel interface and its contact mechanics is a specialist area of tribology, and Dr Fletcher also applies tribological understanding to a range of wider industrial problems. Most recent work has looked at the railway overhead line to pantograph contact that can suffer extreme heating and wear problems due to the high sliding speeds, electric current and variable forces involved. The investigation was conducted by developing a wear testing machine capable of up to 200kph sliding speed, replicating in the laboratory the wear of copper overhead line and pantograph contact strips to better understand their performance.

Rail system design for safety and security

Over recent years European rail systems have been subject to terrorist attack, and their crowded and open nature makes them difficult to protect. Dr Fletcher is conducting research through UK and EU projects aiming to design resilience into stations and vehicles, thereby lowering the risk and impact of attack, and making recovery faster. Knowledge of rail system design and understanding of performance of materials under extreme loading links this area of work with the more conventional engineering aspects of Dr Fletcher's research. An essential aspect of this work is the acceptability to travellers and operators of any change in the design of stations or rail vehicles, and linking design decisions to risk assessment.

Professional Activity

  • Dr Fletcher has conducted research on ESPRC, EU and industrially funded projects with partners including Network Rail, Tata, DeltaRail, London Underground, the Rail Safety and Standards Board, Korean Railroad Research Institute, Japanese Rail Technical research Institute, and the UK Health and Safety Executive.
  • Deputy Director Rail Innovation & Technology Centre, University of Sheffield/Network Rail (2011-)
  • International Committee member for Conference on Contact Mechanics and Wear of Rail/Wheel Systems, CM2012.
  • Executive Committee member of Rail Research UK Association (RRUK-A, 2010-2012)
  • Guest editor for IMechE Journal of Rail and Rapid Transit special issue "Engineering a Secure Railway" (2011)

Major Research Grants and Projects

  • EU Framework 7 project 'SUSTRAIL: The sustainable freight railway - Designing the freight vehicle-track system for higher delivered tonnage with improved availability at reduced cost', 2011-2015
  • EU Framework 7 project: 'SecureStation: Passenger station and terminal design for safety, security and resilience to terrorist attack', 2011-2014
  • EPSRC grant EP/H024743/1 'Factor 20: reducing CO2 emissions from imland transport by a major modal shift to rail', Feasibility account grant 'Freight 2035', 2010-2011
  • EPSRC grant EP/F008635/1 'Resilient design (re-design) for counter-terrorism: Decision support for designing effective and acceptable resilient places', 2007-2010

PhD Students:

  • Smith, L - Rolling Contact Fatigue in Wheel-Rail Contact (2007)
  • Anthistle, T - Modelling blast loading in rail vehicles (2010-)

PhD research opportunities are available in any of my research areas - please contact me for discussion.

Prizes

  • World Congress on Railway Research, Korea, Prize for Best Paper Addressing System Interaction Issues, for paper Three-Dimensional Microstructural Modelling Of Wear, Crack Initiation and Growth in Rail Steel, 2008
  • The Institution of Mechanical Engineers Railway Division, TA Steward-Dyer / F H Trevithick Prize, 2005
  • The Institution of Mechanical Engineers Tribology Trust, Tribology Bronze Medal, 2000
  • The Institution of Mechanical Engineers Railway Division, William Alexander Agnew Meritorious Award / Clarence Noel Goodall Award, 2000
  • The University of Sheffield Herbert Walker Swift Bursary, 2000
  • The Institution of Mechanical Engineers Frederic Barnes Walden Prize, 1994
  • The University of Leeds Foundation Prize in Mechanical Engineering, 1994
  • ICI Prize, University of Leeds, 1993
  • Cameron Iron Works Prize, University of Leeds, 1992

Teaching

Dr Fletcher is module leader for the first year module Mechanical Engineering Design Skills (MEC131). He also teaches Mechanical Engineering in Railways to fourth year MEng and MSc students and is part of the team organising the 3rd year BEng/MEng group design project (MEC307).

Journal articles

Chapters

  • Fletcher D, Burstow M, Kapoor A & Franklin F (2010) Crack Development In Schmid F, Brustow M, Clark S, Eickhoff B, Hiensch M, Hsu SS & Kent S (Ed.), Best Practice in Wheel-Rail Interface Management for Mixed Traffic Railways (pp. 4-19-4-30). University of Birmingham Press
  • Fletcher D (2010) Classical Hertzian Contact Theory In Schmid F, Brustow B, Clark S, Eickhoff B, Hiensch M, Hsu SS & Kent S (Ed.), Best Practice in Wheel-Rail Interface Management for Mixed Traffic Railways (pp. 3-20-3-24). University of Birmingham Press
  • Franklin FJ, Garnham JE, Davis CL, Fletcher DI & Kapoor A (2009) The evolution and failure of pearlitic microstructure in rail steel - observations and modelling, Wheel-Rail Interface Handbook (pp. 311-348).
  • Fletcher DI, Franklin FJ & Kapoor A (2009) Rail surface fatigue and wear, Wheel-Rail Interface Handbook (pp. 280-310).
  • Fletcher D, Franklin FJ, Garnham JE, Davis CL & Kapoor A (2009) The evolution and failure of pearlitic microstructure in rail steel - observations and modelling In Lewis R & Olofsson U (Ed.), Wheel-Rail Interface Handbook (pp. 311-348). CRC Press
  • Fletcher D, Franklin FJ & Kapoor A (2009) Rail surface fatigue and wear In Lewis R & Olofsson U (Ed.), Wheel-Rail Interface Handbook (pp. 280-310). CRC Press
  • Fletcher DI, Kapoor A, Schmid F, Sawley KJ & Ishida M (2001) Tribology of Rail Transport In Bhushan B (Ed.), Modern tribology handbook (pp. 1271-1330). London: CRC.

Conference proceedings papers

  • Lewis SR, Lewis R, Goodwin PS, Fretwell-Smith S, Fletcher DI & Murray K (2016) Laser cladding of railway track to promote wear/RCF, bend fatigue and IBJ Lipping resistance. Civil-Comp Proceedings, Vol. 110
  • Lewis SR, Lewis R, Goodwin PS, Fretwell-Smith S, Fletcher DI & Murray K (2015) Improving Rail Wear and RCF Performance using Laser Cladding. CM2015 - 10th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, 30 August 2015 - 3 September 2015. View this article in WRRO
  • White BT, Arnall AD, Evans MD, Fletcher DI & Lewis R (2015) A Study into the Effect of the Presence of Moisture at the Wheel/Rail Interface during Dew and Damp Conditions. 10th International Conference on Contact Mechanics, CM2015. Colorado Springs, Colorado, USA, 30 August 2015 - 3 September 2015.
  • Arnall AD, Fletcher DI & Lewis R (2015) Geospatial and Temporal Analysis of Wheel Slide Events. 10th International Conference on Contact Mechanics, CM2015. Colorado Springs, Colorado, USA, 30 August 2015 - 3 September 2015.
  • Beagles AE, Arnall AD & Fletcher DI (2015) Interaction of Multiple Cracks in Railheads. 10th International Conference on Contact Mechanics, CM2015. Colorado Springs, Colorado, USA, 30 August 2015 - 3 September 2015.
  • Lewis SR, Riley S, Fletcher DI & Lewis R (2015) Optimisation of a Railway Sanding System, Part 1: Optimal Grain Entrainment into the Wheel/Rail Contact. CM2015
  • Lewis SR, Riley S, Fletcher DI & Lewis R (2015) Optimisation of a Railway Sanding System, Part 2: Adhesion Tests. CM2015
  • Fisk J, Lewis R, Armitage T, Fletcher DI, Evans M & Arnall A (2015) Investigation into the Effect of Moisture on Rail Adhesion. Proceedings of the IMechE Railway Division Stephenson Conference
  • Beagles AE, Beaty P, Fletcher DI, Lewis R & Temple BP (2015) Insulated rail joint enhancement: testing and analysis. The Stephenson Conference: Research for railways. London, UK, 21 April 2015 - 23 April 2015. View this article in WRRO
  • Fletcher DI & Al Battashi T (2015) Adhesion dependence on water dispersion and rail wettability. CM 2015 - 10th International Conference on Contact Mechanics of Wheel / Rail Systems
  • Paragreen J & Fletcher D (2012) A quantitative risk assessment methodology for evaluating security threats to railway and metro stations and interchanges. RRUKA 2012 Annual Conference. www.rssb.co.uk, 7 November 2012 - 7 November 2012.
  • Beagles A & Fletcher D (2012) The aerodynamics of freight; approaches to save fuel by optimising the utilisation of container trains. RRUKA 2012 Annual Conference. www.rssb.co.uk, 7 November 2012 - 7 November 2012.
  • Fletcher DI (2012) Thermal contact stress and near surface rail cracks. 9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, CM 2012 (pp 470-479)
  • Lewis SR, Lewis R & Fletcher D (2012) Assessment of Laser Cladding as an Option for Repair of Rails. 9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems (pp 380-385). Chengdu, China, 27 August 2012 - 30 August 2012.
  • Fletcher D (2010) Destructive Examination of Rails & Evaluation of Thermal Effect of Rail-Wheel Contact. Squat Type Defect Seminar. London Underground, 13 December 2010.
  • Pennie D, Leach P, Cash B, Berman J, Wicksman R, Fletcher D & Edworthy J (2010) Developing and promoting Alarms and Alerts Guidance for the rail industry. Contemporary Ergonomics and Human Factors 2010 (pp 563-571)
  • Fletcher D (2009) An overview of railway research in Mechanical Engineering at The University of Sheffield. Rail Technology Research Institute Seminar. Rail Technology Research Institute (RTRI), Tokyo, Japan, 15 June 2009.
  • Kapoor A, Fletcher DI, Franklin FJ, Vasic G & Smith L (2005) Rail-wheel contact research at the University of Newcastle. 11th International Conference on Fracture 2005, ICF11, Vol. 8 (pp 5596-5601)
  • Fletcher D, Steinhoff K & Kapoor A (2001) The self-forming phenomenon - dynamic restructuring of tool surfaces in metal forming processes. Österreichische Tribologische Gesellschaft (pp 1-4). Wien, 3 September 2001 - 7 September 2001.
  • Fletcher D, Kapoor A, Steinhoff K & Schuleit N (2000) New laser surface treatment for improving mechanical and tribological properties of forming tools. Europäischer Kongress für Wärmebehandlung und mechanische Oberflächenbehandlung "ATTT 2000" (In Engl (pp 29). Paris, 14 June 2000 - 16 June 2000.
  • Hickish RG, Fletcher DI & Harrison RF () Maximising passenger satisfaction through optimised train movements. The Stephenson Conference: Research for Railways
  • Paragreen J, Fletcher D, Costa E & Porziani S () A simulations-driven approach for predicting harmful effects of terrorists attacks and to design mitigation countermeasures. International CAE Conference 2013. Verona, Italy, 21 October 2013 - 23 October 2013.
  • Anthistle T & Fletcher DI () Modelling blast loads in rail vehicles. Structures under Shock and Impact XII (pp 85-97). Kos, Greece, 4 September 2012 - 6 September 2012. View this article in WRRO
  • Fletcher D () Metallurgical background to rail failures. Seminar on the development of squat type defects on the Northern and Jubilee Lines. 20 Jan 2010, 20 January 2010.
  • Fletcher D, Kapoor A, Steinhoff K & Schuleit N () Selbstformung als dynamisches Gestaltungssprinzip für nanometrische Oberflächen auf Umformwerkzeugen (Self-forming structures for nano-metric surfaces on forming tools). Verein Deutscher Eisenhüttenleuten VDEh Grundlagen der Umformtechnik (technical meeting of the Germa. Düsseldorf, Germany, 4 October 1999 - 4 October 1999.
  • Fletcher D, Kapoor A, Steinhoff K & Schuleit N () Improvement of mechanical and tribological properties of forming tools by 3D thermal implants with dispersed metal-carbide particles. 4th European Mechanics of Materials Conference "Euromech - Mecamat", Processes Microstructures Mech. Metz, France, 26 June 2000 - 29 June 2000.
  • Fletcher D, Alwahdi F & Kapoor A () The metallurgy of pearlitic rail steel following service in the UK. World Congress on Railway Research WCRR 2003 (pp 932-939). Edinburgh, 28 September 2003 - 1 October 2003.
  • Fletcher D, Beynon JH, Brown MW, Dwyer-Joyce RS, Kapoor A, Loo-Morrey M & Grieve DG () Integrated study of fatigue and wear of pearlitic rail steels under rolling-sliding contact conditions. 5th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems (CM2000) (pp 104-108). Tokyo, Japan, 25 July 2000 - 28 July 2000.
  • Fletcher D, Hobbs J, Lim T & Kapoor A () The Morphology of Cracks in Rails.. ESIA8 Throughlife Management of Structures & Components (pp 45-54). Manchester, UK, 24 October 2006 - 25 October 2006.
  • Fletcher D, Kamitani S, Kapoor A & Franklin FJ () Hardness and the damage on the rail surface. 11th Railroad Technical Combined Symposium (J-RAIL2004). Japan, 7 December 2004 - 9 December 2004.
  • Fletcher D, Kapoor A, Franklin FJ, Vasic G & Smith L () New Developments In Rail-Wheel Contact Research At The University Of Newcastle. 11th International Conference on Fracture (ICF11). Turin, 20 March 2005 - 25 March 2005.
  • Beagles A & fletcher D () Combining crack-growth, contact geometry, and probabilistic methodology to plan optimised rail grinding. World Congress on Railway Research (WCRR) 2016. Online: https://www.sparkrail.org/Pages/WCRR.aspx, 29 May 2016 - 2 June 2016.

Reports

  • Fletcher D (2010) Crack growth modelling background & KRRI specific cases
  • Fletcher D & Lewis S (2010) Investigation of rail defects
  • Fletcher D & Lewis S (2010) SUROS test on Corus weld repaired steels
  • Fletcher D, Lewis R, Dwyer-Joyce RS & Pugh S (2009) Wear steps in overhead line neutral section
  • Fletcher D & Gallardo-Hernandez EA (2009) Investigation of rail defects
  • Fletcher D & Franklin FJ (2007) Marmaray Project Phase I
  • Fletcher D, Franklin FJ & Kapoor A (2007) Wear fatigue interaction: underlying models, recent developments and grinding predictions
  • Fletcher D, Kapoor A, Franklin FJ, Smith L & Hyde P (2006) Comparison of the Hatfield and alternative UK rails using models to assess the effect of residual stress on crack growth from rolling contact fatigue
  • Fletcher D & Kapoor A (2006) Post Hatfield rolling contact fatigue - The effect of residual stress on contact stress driven crack growth in rail: Combination of bending and contact stresses
  • Fletcher D & Kapoor A (2006) Post Hatfield rolling contact fatigue - The effect of residual stress on contact stress driven crack growth in rail Part 3: Further data
  • Fletcher D & Kapoor A (2006) Post Hatfield rolling contact fatigue - The effect of residual stress on contact stress driven crack growth in rail Part 2: Data
  • Fletcher D & Kapoor A (2006) Post Hatfield rolling contact fatigue - The effect of residual stress on contact stress driven crack growth in rail Part 1: The model
  • Fletcher D & Kapoor A (2006) Post Hatfield rolling contact fatigue - The effect of residual stress on contact stress driven crack growth in rail: Literature review
  • Fletcher D, Evans G & Franklin FJ (2006) RSSB T355 - Management and Understanding of Rolling Contact Fatigue, WP 2 ­ Phase 2 Crack Growth Final Project Report
  • Fletcher D, Kapoor A, Franklin FJ, Smith L & Hyde P (2006) Comparison of the Hatfield and alternative UK rails using models to assess the effect of residual stress on crack growth from rolling contact fatigue
  • Fletcher D, Burstow M, Franklin FJ & Kapoor A (2006) Management and Understanding of Rolling Contact Fatigue, WP1:Mechanisms of Crack Initiation Final Report
  • Fletcher D, Franklin FJ & Kapoor A (2006) Report on Water Solubility of Dried and Liquid Lignin
  • Fletcher D, Franklin FJ, Hyde P & Kapoor A (2006) Track tests on rail-wheel adhesion, RSSB 1121, Characteristics of Railhead Leaf Contamination
  • Fletcher D, Dutton JT, Hobbs JW & Kapoor A (2005) Post Hatfield rolling contact fatigue - Measurement of Crack Depths in a Section of Head Hardened Rail
  • Fletcher D, Kapoor A, Franklin FJ, Beagles AE, Burstow M, Allen R, Evans G & Jaiswal J (2005) Management and Understanding of Rolling Contact Fatigue, WP1: Mechanisms of Crack Initiation, and WP2: Crack Growth. Literature Review
  • Fletcher D, Kapoor A, Franklin FJ & Alwahdi F (2002) Whole life rail model Interim Report
  • Fletcher D (2001) Whole Life Rail Model, Stage 1 final report, University of Sheffield and AEAT
  • Fletcher D & Beynon JH (1998) Simulation of back-up roll contact fatigue
  • Fletcher D & Beynon JH (1998) Survey of damage in rail

Posters

  • Fletcher D & Beynon JH (1997) The influence of solid lubricants on pearlitic rail steel fatigue life. World Tribology Congress, London.

Theses / Dissertations

  • Fletcher D (1999) The Influence of Lubrication on the Fatigue of Pearlitic Rail Steel. University of Sheffield.