Change search
ReferencesLink to record
Permanent link

Direct link
A novel method to model wheel-rail normal contact in vehicle dynamics simulation
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.ORCID iD: 0000-0003-2590-3698
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. Bombardier Transportation, Sweden .ORCID iD: 0000-0002-3447-6686
KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.ORCID iD: 0000-0002-2571-4662
2014 (English)In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 52, no 12, 1752-1764 p.Article in journal (Refereed) Published
Abstract [en]

An approximate analytical method is proposed for calculating the contact patch and pressure distribution in the wheel-rail interface. The deformation of the surfaces in contact is approximated using the separation between them. This makes it possible to estimate the contact patch analytically. The contact pressure distribution in the rolling direction is assumed to be elliptic with its maximum calculated by applying Hertz' solution locally. The results are identical to Hertz's for elliptic cases. In non-elliptic cases good agreement is achieved in comparison to the more accurate but computationally expensive Kalker's variational method (CONTACT code). Compared to simplified non-elliptic contact methods based on virtual penetration, the calculated contact patch and pressure distribution are markedly improved. The computational cost of the proposed method is significantly lower than the more detailed methods, making it worthwhile to be applied to rolling contact in rail vehicle dynamics simulation. Such fast and accurate estimation of contact patch and pressure paves the way for on-line modelling of damage phenomena in dynamics simulation packages.

Place, publisher, year, edition, pages
2014. Vol. 52, no 12, 1752-1764 p.
Keyword [en]
rail vehicle dynamics, Hertz, non-elliptic contact, wheel-rail contact
National Category
Vehicle Engineering
Research subject
Järnvägsgruppen - Fordonsteknik
URN: urn:nbn:se:kth:diva-157589DOI: 10.1080/00423114.2014.961932ISI: 000345075000011ScopusID: 2-s2.0-84911498531OAI: diva2:771123

QC 20150623

Available from: 2014-12-12 Created: 2014-12-11 Last updated: 2016-02-03Bibliographically approved
In thesis
1. On Efficient Modelling of Wheel-Rail Contact in Vehicle Dynamics Simulation
Open this publication in new window or tab >>On Efficient Modelling of Wheel-Rail Contact in Vehicle Dynamics Simulation
2016 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

The wheel-rail contact is at the core of all research related to vehicletrackinteraction. This tiny interface governs the dynamic performanceof rail vehicles through the forces it transmits and, like any high stressconcentration zone, it is subjected to serious damage phenomena. Thus,a clear understanding of the rolling contact between wheel and rail is keyto realistic vehicle dynamics simulation and damage analysis.

In a multi-body dynamics simulation, the demanding contact problemshould be evaluated at about every millisecond for several wheel-rail pairs.Hence, a rigorous treatment of the contact is highly time-consuming.Simplifying assumptions are therefore made to accelerate the simulationprocess. This gives rise to a trade-o between the accuracy and computationaleciency of the contact model in use.

Conventionally, Hertz+FASTSIM is used for calculation of the contactforces thanks to its low computational cost. However, the elliptic patchand pressure distribution obtained by Hertz' theory is often not realisticin wheel-rail contact. Moreover, the use of parabolic traction bound inFASTSIM causes considerable error in the tangential stress estimation.This combination leads to inaccurate damage predictions.

Fast non-elliptic contact models are proposed by others to tacklethis issue while avoiding the tedious numerical procedures. The studiesconducted in the present work show that the accuracy of these models iscase-dependent.

To improve the accuracy of non-elliptic patch and pressure estimation,a new method is proposed. The method is implemented in an algorithmnamed ANALYN. Comparisons show improvements in patch and, particularly,pressure estimations using ANALYN.

In addition, an alternative to the widely-used FASTSIM is developed, named FaStrip. Unlike FASTSIM, it employs an elliptic traction boundand is able to estimate the non-linear characteristic of tangential stressdistribution. Comparisons show more accurate estimation of tangentialstress and slip velocity distribution as well as creep forces with FaStrip.

Ultimately, an ecient non-elliptic wheel-rail contact model consistingof ANALYN and FaStrip is proposed. The reasonable computationalcost of the model enables it to be used on-line in dynamics simulationand its accuracy can improve the damage predictions.

Place, publisher, year, edition, pages
Stockholm: KTH Royal Institute of Technology, 2016. xiv, 97 p.
TRITA-AVE, ISSN 1651-7660 ; 2016:02
wheel-rail contact, non-elliptic contact, rail vehicle dynamics, rolling contact, vehicle-track interaction, wheel-rail damage
National Category
Vehicle Engineering Tribology
Research subject
Järnvägsgruppen - Fordonsteknik; The KTH Railway Group - Tribology; Vehicle and Maritime Engineering
urn:nbn:se:kth:diva-181691 (URN)978-91-7595-846-0 (ISBN)
Public defence
2016-02-24, F3, Lindstedsvägen 26, KTH, Stockholm, 13:15 (English)

QC 20160202

Available from: 2016-02-02 Created: 2016-02-02 Last updated: 2016-02-02Bibliographically approved

Open Access in DiVA

No full text

Other links

Publisher's full textScopus

Search in DiVA

By author/editor
Shahzamanian Sichani, MatinEnblom, RogerBerg, Mats
By organisation
Rail VehiclesThe KTH Railway Group
In the same journal
Vehicle System Dynamics
Vehicle Engineering

Search outside of DiVA

GoogleGoogle Scholar
The number of downloads is the sum of all downloads of full texts. It may include eg previous versions that are now no longer available

Altmetric score

Total: 62 hits
ReferencesLink to record
Permanent link

Direct link