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Publications (10 of 74) Show all publications
Dittes, N., Pettersson, A., Marklund, P., Lang, D. & Lugt, P. M. (2018). Dielectric Thermoscopy Characterization of Water Contaminated Grease. Tribology Transactions, 74(3), 60-73
Open this publication in new window or tab >>Dielectric Thermoscopy Characterization of Water Contaminated Grease
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2018 (English)In: Tribology Transactions, ISSN 1040-2004, E-ISSN 1547-397X, Vol. 74, no 3, p. 60-73Article in journal (Refereed) Published
Abstract [en]

The temperature dependence on the dielectric properties of water-contaminated grease is investigated in this article. The purpose of this investigation was to identify the dielectric properties that could be measured to differentiate varying levels of water contamination in calcium sulfonate complex (CaS-X) grease with three different test cells with the purpose of eventually developing a grease condition sensor. Measuring the change in dielectric constant over a small temperature change yielded useful estimations of water content and amount of grease where the added water content ranged from 0.22% to about 5.5%. Additionally, other parameters such as incomplete fill/coverage of the sensors were investigated as a prestudy. The results from this set of experiments show that the measurement has potential to be developed into a condition monitoring sensor in the future.

Place, publisher, year, edition, pages
Taylor & Francis, 2018
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-65054 (URN)10.1080/10402004.2017.1333664 (DOI)2-s2.0-85045005667 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-04-16 (andbra)

Available from: 2017-08-14 Created: 2017-08-14 Last updated: 2018-04-16Bibliographically approved
Söderfjäll, M., Larsson, R., Marklund, P. & Almqvist, A. (2018). Texture-induced effects causing reduction of friction in mixed lubrication for twin land oil control rings. Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 232(2), 166-178
Open this publication in new window or tab >>Texture-induced effects causing reduction of friction in mixed lubrication for twin land oil control rings
2018 (English)In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 232, no 2, p. 166-178Article in journal (Refereed) Published
Abstract [en]

Piston rings are responsible for a major part of the frictional losses in a heavy-duty diesel engine. Such losses can be reduced by applying texture, such as dimples, on the cylinder liner surface. This paper investigates the effect of such texture on the friction between a land of the oil control ring and a textured cylinder liner via numerical simulation. A simulation model considering inertia and mixed lubrication together with a mass-conserving cavitation model is developed. The model is used to determine the dimple parameters that yield the lowest amount of friction for a specific oil control ring of a heavy-duty diesel engine

Place, publisher, year, edition, pages
Sage Publications, 2018
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-63889 (URN)10.1177/1350650117709152 (DOI)000424781600008 ()2-s2.0-85042864633 (Scopus ID)
Note

Validerad;2018;Nivå 2;2018-02-12 (svasva)

Available from: 2017-06-12 Created: 2017-06-12 Last updated: 2018-03-14Bibliographically approved
Schnabel, S., Golling, S., Marklund, P. & Larsson, R. (2017). Absolute Measurement of Elastic Waves Excited by Hertzian Contacts in Boundary Restricted Systems. Tribology letters, 65(1), Article ID 7.
Open this publication in new window or tab >>Absolute Measurement of Elastic Waves Excited by Hertzian Contacts in Boundary Restricted Systems
2017 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 65, no 1, article id 7Article in journal (Refereed) Published
Abstract [en]

In most applied monitoring investigations using acoustic emission, measurements are carried out relatively, even though that limits the use of the extracted information. The authors believe acoustic emission monitoring can be improved by instead using absolute measurements. However, knowledge about absolute measurement in boundary restricted systems is limited. This article evaluates a method for absolute calibration of acoustic emission transducers and evaluates its performance in a boundary restricted system. Absolute measured signals of Hertzian contact excited elastic waves in boundary restricted systems were studied with respect to contact time and excitation energy. Good agreement is shown between measured and calculated signals. For contact times short enough to avoid interaction between elastic waves and initiating forces, the signals contain both resonances and zero frequencies, whereas for longer contact times the signals exclusively contained resonances. For both cases, a Green’s function model and measured signals showed good agreement.

Keywords
Hertz contact, Elastic waves, Acoustic emission, Green’s function, Boundary restricted system, Condition monitoring
National Category
Applied Mechanics Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-60934 (URN)10.1007/s11249-016-0790-8 (DOI)000397039300007 ()2-s2.0-85000359790 (Scopus ID)
Funder
VINNOVA, 198503
Note

Validerad; 2017; Nivå 2; 2016-12-19 (andbra)

Available from: 2016-12-06 Created: 2016-12-06 Last updated: 2018-07-10Bibliographically approved
Strömbergsson, D., Marklund, P., Edin, E. & Zeman, F. (2017). Acoustic emission monitoring of a mechanochemical surface finishing process. Tribology International, 112, 129-136
Open this publication in new window or tab >>Acoustic emission monitoring of a mechanochemical surface finishing process
2017 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 112, p. 129-136Article in journal (Refereed) Published
Abstract [en]

Acoustic emission monitoring of cutting machining operations is an established researched area, though monitoring non-removal finishing processes is less studied.

This work presents an initial investigation on Acoustic emissions potential of an mechanochemical superfinishing process. Conclusions are drawn from the monitoring signal regarding the resulting surface friction characteristics, composition and possible runnability issues.

Monitoring data was collected from tests performed at Applied Nano Surfaces' testing laboratory. Test series with varying parameters enabled a correlation analysis between the monitoring data, surface friction characteristics and tribofilm formation. Increasing tool wear tests were monitored to find early runnability warning.

Results shows Acoustic emissions indication potential when the finishing process has achieved the intended friction reduction, tribofilm deposition as well as runnability issues identification.

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-62937 (URN)10.1016/j.triboint.2017.03.031 (DOI)000401217100015 ()2-s2.0-85017199001 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-04-18 (rokbeg)

Available from: 2017-04-07 Created: 2017-04-07 Last updated: 2018-07-10Bibliographically approved
Martin del Campo Barraza, S., Schnabel, S., Sandin, F. & Marklund, P. (2017). Detection of particle contaminants in rolling element bearings with unsupervised acoustic emission feature learning. Tribology International
Open this publication in new window or tab >>Detection of particle contaminants in rolling element bearings with unsupervised acoustic emission feature learning
2017 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464Article in journal (Other academic) Submitted
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Machine Elements; Industrial Electronics
Identifiers
urn:nbn:se:ltu:diva-63112 (URN)
Available from: 2017-04-21 Created: 2017-04-21 Last updated: 2018-03-09
Schnabel, S., Marklund, P. & Larsson, R. (2017). Elastic Waves of a Single Elasto-Hydrodynamically Lubricated Contact. Tribology letters, 65(1), Article ID 5.
Open this publication in new window or tab >>Elastic Waves of a Single Elasto-Hydrodynamically Lubricated Contact
2017 (English)In: Tribology letters, ISSN 1023-8883, E-ISSN 1573-2711, Vol. 65, no 1, article id 5Article in journal (Refereed) Published
Abstract [en]

Elastic waves are widely used for condition monitoring of rolling element bearings through vibration or acoustic emission measurements . While vibration signals are understood to a high degree due to many scientific investigations as well as a long history of usage in the field, acoustic emission signals of rolling element bearings are poorly understood. Therefore, this investigation presents simulation studies and measurements of a single elasto-hydrodynamically lubricated (EHL) contact. In this investigation the EHL contact is a ball bouncing on a lubricated plate. The simulation based on Green’s function and the measurements based on a accelerometer to some extent agree. A shift of zero frequencies towards higher frequencies when compared to Hertzian reference measurements was determined for an infinite plate setup. Taking boundary restrictions into account, elastic waves of a Hertzian contact and an EHL contact only differ by a damping of higher resonances which is most likely caused by the EHL film.

Keywords
EHL contact, EHL, Hertz contact, Elastic waves, Acoustic emission, Green’s function, Ball impact, Bouncing ball
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Fluid Mechanics and Acoustics Applied Mechanics
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-60962 (URN)10.1007/s11249-016-0785-5 (DOI)000397039300005 ()2-s2.0-85000443041 (Scopus ID)
Funder
VINNOVA, 198503
Note

Validerad; 2017; Nivå 2; 2016-12-19 (andbra)

Available from: 2016-12-07 Created: 2016-12-07 Last updated: 2018-07-10Bibliographically approved
Schnabel, S., Marklund, P., Larsson, R. & Golling, S. (2017). The Detection of Plastic Deformation in Rolling Element Bearings by Acoustic Emission. Tribology International, 110, 209-215
Open this publication in new window or tab >>The Detection of Plastic Deformation in Rolling Element Bearings by Acoustic Emission
2017 (English)In: Tribology International, ISSN 0301-679X, E-ISSN 1879-2464, Vol. 110, p. 209-215Article in journal (Refereed) Published
Abstract [en]

The detection of plastic deformation caused by particle contamination in rolling element bearings using acoustic emission is reliable at low speeds as shown in several studies. However, there are no studies at greater speeds of the detection of plastic deformation by acoustic emission in rolling element bearings. The acoustic emission signals of rolling element bearings have, however, been shown to be dominated by transient force signals which are elastic waves caused by transient forces acting at the raceway surface. The results of the test showed a dominance of transient force signals at elevated speeds, which masks signals caused by plastic deformation and prohibits the detection of particle contamination, while at low rotational speed plastic deformation is detected by acoustic emission.

National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear) Applied Mechanics
Research subject
Machine Elements; Solid Mechanics
Identifiers
urn:nbn:se:ltu:diva-62088 (URN)10.1016/j.triboint.2017.02.021 (DOI)000398871700023 ()2-s2.0-85013782176 (Scopus ID)
Note

Validerad; 2017; Nivå 2; 2017-03-09 (andbra)

Available from: 2017-02-20 Created: 2017-02-20 Last updated: 2018-07-10Bibliographically approved
Schnabel, S., Golling, S., Marklund, P. & Larsson, R. (2017). The influence of contact time and event frequency on acoustic emission signals. Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 231(10), 1341-1349
Open this publication in new window or tab >>The influence of contact time and event frequency on acoustic emission signals
2017 (English)In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 231, no 10, p. 1341-1349Article in journal (Refereed) Published
Abstract [en]

Studies of acoustic emissions (AE) of rotating machine elements is often performed under a constant speed. There are few investigations on speed and contact time dependency of acoustic emission signals, even though some investigations have reported difficulties at elevated rotational speeds. Simplified experiments are, therefore, presented in this article to increase the understanding of the time dependency of acoustic emission signals. Hertzian impacts and tensile tests are used to study contact time, the time duration of an event and offset time, the time between events and accordingly the event frequency. The results of these model experiments indicate an indirect quadratic proportionality of acoustic emission amplitudes and contact time (umax∝1/(tc2)">u max ∝1/(t 2 c ) umax∝1/(tc2) ), as well as a proportional relationship between the root mean square and event frequency (RMS∝fevent∝1/toffset">RMS∝f event ∝1/t offset  RMS∝fevent∝1/toffset ). The relationship between contact time and the root mean square of acoustic emission signals is strongly dependent on the damping of the system

Place, publisher, year, edition, pages
Sage Publications, 2017
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-62114 (URN)10.1177/1350650117693176 (DOI)000412739600008 ()2-s2.0-85031315259 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-10-16 (svasva)

Available from: 2017-02-22 Created: 2017-02-22 Last updated: 2018-03-09Bibliographically approved
Lingesten, N., Marklund, P. & Höglund, E. (2017). The influence of repeated high-energy engagements on the permeability of a paper-based wet clutch friction material. Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, 231(12), 1574-1582
Open this publication in new window or tab >>The influence of repeated high-energy engagements on the permeability of a paper-based wet clutch friction material
2017 (English)In: Proceedings of the Institution of mechanical engineers. Part J, journal of engineering tribology, ISSN 1350-6501, E-ISSN 2041-305X, Vol. 231, no 12, p. 1574-1582Article in journal (Refereed) Published
Abstract [en]

The behavior of a wet clutch during engagement is of great importance to the durability of the clutch and the drivability of a vehicle. While many different factors influence the engagement behavior, the focus of this paper is to investigate only one factor, the permeability of the wet clutch friction material. Two test cells for measuring the permeability of friction material mounted on clutch discs have been developed. The test cells were then used to examine the effect of clutch material ageing through clutch engagement on the permeability of the material. The tests were performed on full size friction discs including the steel core prior and subsequent to testing in a wet clutch engagement test rig. The ability of the friction material to allow for oil flow both through the sliding surface layer and the bulk of the material was measured. The results indicate that repeated clutch engagements will increase the bulk permeability. However, the repeated engagements will decrease the ability to pass fluid through the friction material sliding surface. This contradictory behavior could be explained by a combination of an increase in pore size through repeated compression and the surface glaze clogging of the friction interface surface pores.

Place, publisher, year, edition, pages
Sage Publications, 2017
National Category
Tribology (Interacting Surfaces including Friction, Lubrication and Wear)
Research subject
Machine Elements
Identifiers
urn:nbn:se:ltu:diva-63441 (URN)10.1177/1350650117700807 (DOI)000416568100006 ()2-s2.0-85036671340 (Scopus ID)
Note

Validerad;2017;Nivå 2;2017-12-05 (andbra)

Available from: 2017-05-18 Created: 2017-05-18 Last updated: 2018-03-09Bibliographically approved
Martin del Campo Barraza, S., Sandin, F., Schnabel, S., Marklund, P. & Delsing, J. (2016). Exploratory Analysis of Acoustic Emissions in Steel using Dictionary Learning. In: IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016: . Paper presented at IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016. Piscataway, NJ: IEEE conference proceedings, Article ID 7728825.
Open this publication in new window or tab >>Exploratory Analysis of Acoustic Emissions in Steel using Dictionary Learning
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2016 (English)In: IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016, Piscataway, NJ: IEEE conference proceedings, 2016, article id 7728825Conference paper, Published paper (Refereed)
Abstract [en]

Analysis of acoustic emissions (AE) from steel deformation is a challenging condition monitoring problem due to the high frequencies and data rates involved, and the difficulty to separate signals from noise. The problem to characterize and identify different AE sources calls for methods that goes beyond conventional time and frequency domain analysis. Feature learning is common in the field of machine learning and is successfully used to approximate and classify other kinds of complex signals. Former studies show that AE classification results depend on the choice of predefined features that are extracted from the raw AE signal, but little is known about feature learning in this context. Here we use dictionary learning and sparse coding to optimize a set of shift-invariant features to the AE signal measured in a steel tensile strength test. The specimen undergoes elastic and plastic deformation and eventually cracks. We investigate the learned features and their repetition rates and use principal component analysis (PCA) to illustrate that the resulting sparse AE code is useful for classification of the three strain stages, without reference to the signal amplitude. Therefore, feature learning is a potentially useful approach to the AE analysis problem, which also opens up for further studies of automated methods for anomaly detection in AE.

Place, publisher, year, edition, pages
Piscataway, NJ: IEEE conference proceedings, 2016
Series
Proceedings - IEEE Ultrasonics Symposium, ISSN 1948-5719
Keywords
Dictionary Learning, Acoustic Emission
National Category
Other Electrical Engineering, Electronic Engineering, Information Engineering
Research subject
Industrial Electronics; Machine Elements
Identifiers
urn:nbn:se:ltu:diva-59776 (URN)10.1109/ULTSYM.2016.7728825 (DOI)000387497400452 ()2-s2.0-84996567218 (Scopus ID)978-1-4673-9897-8 (ISBN)978-1-4673-9898-5 (ISBN)
Conference
IEEE Ultrasonics Symposium 2016, Tours France, September 18-21, 2016
Available from: 2016-10-16 Created: 2016-10-16 Last updated: 2018-05-04Bibliographically approved
Organisations
Identifiers
ORCID iD: ORCID iD iconorcid.org/0000-0003-3157-4632

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