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Thomas, Tom R.
Alternative names
Publications (10 of 19) Show all publications
Anderberg, C., Dimkovski, Z., Rosén, B. G. & Thomas, T. R. (2019). Low friction and emission cylinder liner surfaces and the influence of surface topography and scale. Tribology International, 133, 224-229
Open this publication in new window or tab >>Low friction and emission cylinder liner surfaces and the influence of surface topography and scale
2019 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 133, p. 224-229Article in journal (Refereed) Published
Abstract [en]

A low friction piston ring pack, with tangential load halved, was tested in engines with four different cylinder liner finishes. Oil consumption, oil temperature and liner surface temperature were monitored at different load and speed levels, under similar test conditions. The two smoother surfaces generally kept lower oil consumption compared to the two rougher ones. Results were correlated using an area-fractal analysis. The relative area of the surface was calculated at different scales and the result was compared with the level of oil consumption for the different liner surfaces at different engine speeds. It was found that oil consumption was strongly correlated with scale for areas of above 1000 μm2 and below 20 μm2.  © 2018

Place, publisher, year, edition, pages
Kidlington: Pergamon Press, 2019
Keywords
Cylinder liners, Oil consumption, Roughness, Fractal analysis
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:hh:diva-38859 (URN)10.1016/j.triboint.2018.11.022 (DOI)000458943500021 ()2-s2.0-85060228503 (Scopus ID)
Funder
Vinnova, 32534-1
Note

Funding: Volvo Cars in Göteborg & VINNOVA

Available from: 2019-02-07 Created: 2019-02-07 Last updated: 2025-02-14Bibliographically approved
Thomas, T. (2014). Roughness and function. Surface Topography: Metrology and Properties, 2(1), Article ID 014001.
Open this publication in new window or tab >>Roughness and function
2014 (English)In: Surface Topography: Metrology and Properties, ISSN 2051-672X, Vol. 2, no 1, article id 014001Article in journal (Refereed) Published
Abstract [en]

A function map is used to locate applications of roughness in separation-velocity space. The importance of roughness in contact mechanics is demonstrated and versions of the plasticity index are introduced and compared. Case studies of roughness and function are presented from tribology and the life sciences. Tribological examples are taken from the automotive industry and include the manufacture of vehicle bodies, and drive train tribology, particularly cylinder liner, cam and gearbox friction and wear. From the life sciences, problems of prosthetic fixation and tribology are shown to depend on roughness. The interaction of haptics and surface finish is described and illustrated. A number of other areas of application are listed. Finally the likely future importance of structured surfaces is discussed. © 2014 IOP Publishing Ltd.

Place, publisher, year, edition, pages
Bristol, United Kingdom: Institute of Physics Publishing (IOPP), 2014
National Category
Materials Engineering Mechanical Engineering
Identifiers
urn:nbn:se:hh:diva-25167 (URN)10.1088/2051-672X/2/1/014001 (DOI)2-s2.0-84979197354 (Scopus ID)
Available from: 2014-04-28 Created: 2014-04-28 Last updated: 2022-09-13Bibliographically approved
Rosén, S., Thomas, T. & Rosén, B.-G. (2014). The Stedman diagram revisited. Surface Topography : Metrology and Properties, 2(1), Article ID 014005.
Open this publication in new window or tab >>The Stedman diagram revisited
2014 (English)In: Surface Topography : Metrology and Properties, ISSN 2051-672X, Vol. 2, no 1, article id 014005Article in journal (Refereed) Published
Abstract [en]

The Stedman diagram has been used for some years to display aspects of the performance of instruments measuring surface roughness. Such diagrams are herein employed to compare the features of a range of proprietary measuring instruments, including contact and non-contact devices. An extension of the basic diagram is proposed, which would allow it to include a further aspect: the speed of data collection. Figures of merit based on the revised diagram are computed, which enable instruments to be ranked on these particular aspects of their performance. Contact instruments emerge as comparable to non-contact, as their slower rate of data acquisition can be offset by the greater area they can access in amplitude–wavelength space. © 2014 IOP Publishing Ltd.

Place, publisher, year, edition, pages
Bristol: Institute of Physics (IOP), 2014
National Category
Medical Laboratory Technologies
Identifiers
urn:nbn:se:hh:diva-25266 (URN)10.1088/2051-672X/2/1/014005 (DOI)2-s2.0-84979198601 (Scopus ID)
Note

Special Issue: Selected papers from the 14th International Conference on Metrology and Properties of Engineering Surfaces (Met & Props 2013), held on 17–21 June 2013 Taipei, Taiwan

Available from: 2014-04-30 Created: 2014-04-30 Last updated: 2025-02-09Bibliographically approved
Thomas, T. (2013). Engineering applications of surface topography. International Journal of Precision Technology, 3(4), 333-353
Open this publication in new window or tab >>Engineering applications of surface topography
2013 (English)In: International Journal of Precision Technology, ISSN 1755-2079, Vol. 3, no 4, p. 333-353Article in journal (Refereed) Published
Abstract [en]

A taxonomy of applications is developed using the concept of function maps. The importance of roughness in contact mechanics is emphasised and alternative models of the plasticity index are revisited. The concept of contact resistance is shown to be strongly dependent on roughness. Further discussions are illustrated by a selection of case studies. Case studies from the life sciences include a discussion of dental and femoral prosthetics and architectural haptics. Tribological case studies are based on automotive problems, including manufacture of body parts, cylinder bore friction and lubrication, rocker cam wear and gear lubrication. It is concluded that the future of roughness studies lies with applications; that only a small number of currently available roughness parameters appear to have any practical use; and that much current work may eventually made obsolete by the increasing development of structured surfaces.

Place, publisher, year, edition, pages
Olney, United Kingdom: InderScience Publishers, 2013
Keywords
Function maps, contact mechanics, surface topography, automotive tribology, plasticity index
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:hh:diva-25166 (URN)10.1504/IJPTECH.2013.058256 (DOI)
Available from: 2014-04-28 Created: 2014-04-28 Last updated: 2025-02-14Bibliographically approved
Thomas, T. (2013). Roughness and function. In: Metrology and Properties of Engineering Surfaces, 2013: Proceedings of the 14th International Conference, Taipei, Taiwan, June 17-21, 2013. Paper presented at 14th International Conference on Metrology and Properties of Engineering Surfaces, Taipei, Taiwan, June 17-21, 2013. Taipei, Taiwan
Open this publication in new window or tab >>Roughness and function
2013 (English)In: Metrology and Properties of Engineering Surfaces, 2013: Proceedings of the 14th International Conference, Taipei, Taiwan, June 17-21, 2013, Taipei, Taiwan, 2013Conference paper, Published paper (Refereed)
Abstract [en]

A function map is used to locate applications of roughness in separation-velocity space. The importance of roughness in contact mechanics is demonstrated and versions of the plasticity index are introduced and compared. Case studies of roughness and function are presented from tribology and the life sciences. Tribological examples are taken from the automotive industry and include the manufacture of vehicle bodies, and drive train tribology, particularly cylinder liner, cam and gearbox friction and wear. From the life sciences, problems of prosthetic fixation and tribology are shown to depend on roughness. The interaction of haptics and surface finish is described and illustrated. A number of other areas of application are listed. Finally the likely future importance of structured surfaces is discussed.

Place, publisher, year, edition, pages
Taipei, Taiwan: , 2013
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:hh:diva-25170 (URN)
Conference
14th International Conference on Metrology and Properties of Engineering Surfaces, Taipei, Taiwan, June 17-21, 2013
Available from: 2014-04-28 Created: 2014-04-28 Last updated: 2025-02-14Bibliographically approved
Rosén, S., Thomas, T. & Rosén, B.-G. (2013). The Stedman diagram revisited. In: Metrology and Properties of Engineering Surfaces, 2013: Proceedings of the 14th International Conference, Taipei, Taiwan, June 17-21, 2013. Paper presented at The 14th International Conference on Metrology and Properties of Engineering Surfaces, June 17-21, 2013, Taipei, Taiwan (pp. 201-206).
Open this publication in new window or tab >>The Stedman diagram revisited
2013 (English)In: Metrology and Properties of Engineering Surfaces, 2013: Proceedings of the 14th International Conference, Taipei, Taiwan, June 17-21, 2013, 2013, p. 201-206Conference paper, Published paper (Refereed)
Abstract [en]

The Stedman diagram has been used for some years to display aspects of the performance of surface roughness measuring instruments. Such diagrams are herein employed to compare the features of a range of proprietary measuring instruments, including contact and non-contact devices. An extension of the basic diagram is proposed which would allow it to include a further aspect, speed of data collection. Figures of merit based on the revised diagram are computed which enable instruments to be ranked on these particular aspects of their performance. Contact instruments emerge as comparable to non-contact, as their slower rate of data acquisition can be offset by the greater area they can access in amplitude-wavelength space.

National Category
Medical Laboratory Technologies
Identifiers
urn:nbn:se:hh:diva-25171 (URN)
Conference
The 14th International Conference on Metrology and Properties of Engineering Surfaces, June 17-21, 2013, Taipei, Taiwan
Available from: 2014-04-28 Created: 2014-04-28 Last updated: 2025-02-09Bibliographically approved
Thomas, T. R., Rosén, B.- . -., Zahouani, H., Blunt, L. & El Mansori, M. (2011). Traceology, quantifying finishing machining and function: A tool and wear mark characterisation study. Wear, 271(3-4), 553-558
Open this publication in new window or tab >>Traceology, quantifying finishing machining and function: A tool and wear mark characterisation study
Show others...
2011 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 271, no 3-4, p. 553-558Article in journal (Refereed) Published
Abstract [en]

Traceology is defined as the study of wear marks and its history in criminology and archaeology is briefly described. It is proposed that the concept of traceology can be extended to machined surfaces, particularly those produced by abrasive techniques. A taxonomy of wear marks is outlined which would encompass both pits and scratches. Taxonomic implementations such as the morphology rose and the morphological tree are introduced. The general principles of traceology are illustrated by case studies from criminology, archaeology and abrasive machining processes.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2011
Keywords
Machining, Abrasives, Diamond cutting tools, Abrasive machining, Characterisation, Machined surface, Wear marks
National Category
Production Engineering, Human Work Science and Ergonomics
Identifiers
urn:nbn:se:hh:diva-14246 (URN)10.1016/j.wear.2010.04.025 (DOI)000292678600012 ()2-s2.0-77952499114 (Scopus ID)
Projects
Linersurf2PolSurf
Available from: 2011-01-27 Created: 2011-01-27 Last updated: 2018-03-23Bibliographically approved
Zahouani, H., Mezghani, M., El Mansori, M., Rosén, B.-G. & Thomas, T. (2009). Effect of Hölder Exponent of Roughness in Contact and Dry Friction Problems. In: P. Pawlus, L. Blunt, B.-G. Rosén, T. Thomas, M. Wieczorowski, H. Zahouani (Ed.), Proceedings of the 12th International Conference on Metrology and Properties of Engineering Surfaces. Paper presented at 12th International Conference on Metrology and Properties of Engineering Surfaces, Rzeszów, 8-10July, 2009. Rzeszow: Rzeszow Univ. of Technology
Open this publication in new window or tab >>Effect of Hölder Exponent of Roughness in Contact and Dry Friction Problems
Show others...
2009 (English)In: Proceedings of the 12th International Conference on Metrology and Properties of Engineering Surfaces / [ed] P. Pawlus, L. Blunt, B.-G. Rosén, T. Thomas, M. Wieczorowski, H. Zahouani, Rzeszow: Rzeszow Univ. of Technology , 2009Conference paper, Published paper (Refereed)
Place, publisher, year, edition, pages
Rzeszow: Rzeszow Univ. of Technology, 2009
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:hh:diva-16358 (URN)978-83-7199-545-3 (ISBN)
Conference
12th International Conference on Metrology and Properties of Engineering Surfaces, Rzeszów, 8-10July, 2009
Available from: 2011-09-27 Created: 2011-09-27 Last updated: 2025-02-14Bibliographically approved
Thomas, T. (2009). Fractal Analysis of Hip Prosthesis Roughness and Wear. Paper presented at International Conference on Bioengineering and Biomaterials. Meknes,18-20 March,2009.
Open this publication in new window or tab >>Fractal Analysis of Hip Prosthesis Roughness and Wear
2009 (English)Conference paper, Published paper (Refereed)
National Category
Other Mechanical Engineering
Identifiers
urn:nbn:se:hh:diva-16357 (URN)
Conference
International Conference on Bioengineering and Biomaterials. Meknes,18-20 March,2009
Available from: 2011-09-27 Created: 2011-09-27 Last updated: 2025-02-14Bibliographically approved
Thomas, T. R. (2009). Kenneth J. Stout 1941-2006: a memorial. Wear, 266(5-6), 490-497
Open this publication in new window or tab >>Kenneth J. Stout 1941-2006: a memorial
2009 (English)In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 266, no 5-6, p. 490-497Article in journal (Refereed) Published
Abstract [en]

Kenneth J. Stout was an important figure in the development of surface metrology, and in particular of roughness measurement and characterisation, during the last decades of the twentieth century. He made substantial contributions to the statistical characterisation of rough surfaces and the application of this work to tribological measurements. Later he was instrumental in developing and popularising practical techniques for three-dimensional description of surface roughness, including the well known "Birmingham 14" set of roughness parameters. Finally he was one of the first to promote the application of wavelet transforms to surface metrology. This memorial discusses his personal contribution to the subject and attempts to set it in the context of historical developments in the field. It includes what is hoped to be a definitive bibliography of his journal publications and those of his co-workers.

Place, publisher, year, edition, pages
Amsterdam: Elsevier, 2009
Keywords
Roughness, Surface characterisation, Topography, 3D measurement, Wavelets
National Category
Engineering and Technology
Identifiers
urn:nbn:se:hh:diva-3529 (URN)10.1016/j.wear.2008.04.053 (DOI)000264568600002 ()
Available from: 2010-01-22 Created: 2009-12-01 Last updated: 2018-03-23Bibliographically approved
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