dr.ir. R. Bosman

Contact:

Room: Horstring N-105

Email: r.bosman@utwente.nl

Telephone: 053 489 6075

Education:

PhD in Mechanical Engineering, Surface Technology and Tribology (Feb.2007- Jan.2011).

University of Twente, The Netherlands.

Project title: “Mild Microscopic Wear Modelling in the Boundary Lubrication Regime”.

M.Sc. in Mechanical Engineering, Non-linear mechanics group (Jun. 2006-Feb. 2007)

University of Twente, The Netherlands

Project title: “Design of a Lubricant Free Piston Compressor”

Research interests:

·

Wear prevention and Modelling

·

Advanced Contact Modelling

·

Elasto-Plastic Material Behavior

·

Transient Contact Computations

·

Maintenance and Maintenance Concepts

·

Tribo-induced surface layers

·

Additives

Current projects that are running under (co) Supervision:

Durability of Camshafts:

PhD student: Vacancy

Increasing regulations on exhaust gasses produced by combustion engines required a constant developed of more efficient and clearer engines. This requires an redesign of the camshaft. However, this engine component is very sensitive to Rolling Contact Fatigue (RCF). Therefore, the stresses and strains just underneath the surface need to be predicted very accurately to be able to maximize the camshaft design regarding efficiency (higher lump angels). This project concentrates on modelling these stresses and includes the transient behaviour of the metastable material. This project is done in cooperation with M2I and DAF.

Sustainable Switches

PhD Student: ir. M. Oomen

In the Dutch railway approximately every week 2 points/frogs must be replaced urgently, which means an average of 100 urgent replacements per year. This problems needs to be handled urgently. One of the solutions is to add a friction modifier to the wheel-rail contact. However, this needs to be done in a controlled manner to guarantee save operations of the tracks. Therefore, first a sound understanding of the effect the friction modifier has on the traction needs to be obtained and the underlying principles unveiled. This project is part of a 3 PhD wide program in cooperation with Technical University of Delft and Prorail.

Wear model to predict the generation of particles from lubricated contacts contributing to the prediction of the reliability of bearings

PhD Student: A. Akchurin, MSc

90 Percent of all bearings are lubricated for life. This means that the bearing is filled with lubricating grease during production and never re-lubricated during usage. Therefore, the life of the lubricating grease determines the life of the bearing. Oxidation has a detrimental effect on the life-time of the grease and is accelerated by the presence of metallic wear particles originating from the cage-roller contact as they work as a catalyst on this process. Within this project the goal is to formulate a model to predict the size and shape of these particles to predict the oxidation rate of grease in bearings more accurately. This project is done in cooperation with M2I and SKF

The impact of water contamination on Grease Performance

PhD Student: F. Cyriac, MSc

Many bearings lubricated by grease are contaminated with water, which can originate from different origins such as coolant, condensation or from an cleaning process. The effect this water contamination has on the lubricating properties of grease are until yet not well understood and the countermeasure is increased re-lubrication of the bearing or reduced lifetime estimations out of precaution. To reduce the redundancy of these measures a better understanding and a quantification of the effect water has needs to be obtained. This project is done in cooperation with SKF and M2I.

Mechanical Aging of Grease

PhD Student: ir. N. Kuipers

Lubricating grease inside rolling-element bearings is sheared, over-rolled and churned during the lifetime of the bearing. This mechanical loading of the grease has an great impact on the properties of the grease. The structure of the grease is destroyed and important factors such as the yield stress or significantly reduced. These effects need to be quantified to be able to estimate the lifetime of lubricated for life bearings and lubrication intervals of grease lubricated bearings. This project is done in cooperation with SKF.

The effect of Surface Finishing on Wear

PhD Student: dipl-ing D. Stickel.

Currently almost all surface finishing process are optimized to remove as much material as possible with the least amount of energy input. In this process almost no attention is paid to the resulting surface properties, only the remaining roughness is analysed. However, this is not the most dominant parameter concerning the wear of engineering components. The layers formed underneath the surface are much more dominant. These layer consist of mechanically altered metallic material (Nano-Crysalline) and chemical layers. The formation and properties of these layers are very sensitive to the amount of energy put into the surface during production and need to be taken into account when optimizing surface finishing. This project is done at the University of Duisburg-Essen in cooperation with prof. A. Fischer.

Selected Publications:

Journal articles

R. Bosman and D.J Schipper, Mild Wear Maps for Boundary Lubricated Contacts, Wear, vol 280, 2012, pp 54-64, DOI:10.1016/j.wear.2012.01.019

R. Bosman, J. Hol and D.J. Schipper Running-in of metallic surfaces in the boundary lubrication regime, , Wear, vol 271, 2011 pp. 1134-1146, DOI: 10.1016/j.wear.2011.05.008

R. Bosman and D.J. Schipper, Running-in of systems protected by additive-rich oils, Tribology Letters, vol 41, 2011, pp. 263-282, DOI: 10.1007/s11249-010-9713-2

R. Bosman and D.J. Schipper, Mild wear prediction of boundary-lubricated contacts, Tribology Letters, vol 42, 2011, pp. 169-178,DOI: 10.1007/s11249-011-9760-3

R. Bosman and D.J. Schipper, Transition from mild to severe wear including running-in effects, Wear, vol 270, 2011 pp. 472-478, DOI: 10.1016/j.wear.2010.12.009

R. Bosman and D.J. Schipper, On the transistion from mild to severe wear of lubricated, concentrated contacts: The IRG (OECD) transition diagram, Wear, vol 269, 2010, pp. 263-282, DOI: 10.1016/j.wear.2010.06.005

R. Bosman and M.B. de Rooij, Transient thermal effects and heat partition in sliding contacts, Journal of Tribology, 2010, vol 132, pp. 1-9, DOI: 10.1115/1.4000693

R. Bosman, Mild Microscopic wear in the boundary lubricated regime, Materials Science and Engineering Technology, 2010, vol. 41, pp. 29-32.DOI: 10.1002/mawe.200900532

Conference articles

R. Bosman, ‘Mild microscopic wear modelling, a transition diagram’, Proceeding of the Wear and Wear prevention congress organised by DGM, 2008, Aachen.

R. Bosman, “Prediction of mild wear in the Boundary Lubrication Regime”, Proceedings of the 29th meeting of the international research group on wear of engineering materials IRG-OECD, ISBN 978-90-365-3453-6

F. Cyriac, P.M Lugt, R. Bosman, 'Impact of water on Calcium Sulfonate greases', ASME/STLE International Joint Tribology Conference 2014, accepted.