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  • 1.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Greenhouse gas emissions from rail services: Present and future2010In: Proceedings of Railways and Environment, 2010Conference paper (Refereed)
  • 2.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Nelldal, Bo-Lennart
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    TOSCA. Rail freight transport: Techno-economic analysis of energy and greenhouse gas reductions2011Report (Other academic)
    Abstract [en]

    In Stage 1 of the EU/FP7-funded project TOSCA (Technology Opportunities and Strategies toward Climate-friendly trAnsport) the techno-economical feasibility of different technolo-gies and means to reduce greenhouse gas (GHG) emissions is being analysed for different modes of transport. This is made over the long-term perspective until 2050, with 2009 as the reference year. This is the report on the rail freight transport market, applicable to the European Union (EU-27).The analysis presented in this report estimates that a number of efficient technologies and means are available, individually and in combination, to significantly reduce energy use and the resulting GHG emissions on the rail freight market until 2050. The analysis has considered the following technologies and means:

    – heavy freight trains (high payload capacity per metre of train as well as longer trains)

    – eco-driving, including traffic flow management

    – energy recovery

    – high-efficiency machinery in locomotives and electric supply

    – low air drag

    – incremental improvements, in particular reduced tare mass of wagons.

    Despite anticipated higher train speeds in most future train operations the above-mentioned technologies and means have, according to the analysis, the potential to reduce the average energy use per net-tonne-km (tkm) of payload by 40–50 % until 2050. As a consequence also the direct and indirect GHG emissions will be reduced. Energy use and GHG emissions are measured per net-tonne-km, assuming representative load factors in different operations.

  • 3.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Nelldal, Bo-Lennart
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Traffic and Logistics. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    TOSCA. Rail passenger transport: Techno-economic analysis of energy and greenhouse gas reductions2011Report (Other academic)
    Abstract [en]

    In Stage 1 of the EU/FP7-funded project TOSCA (Technology Opportunities and Strategies toward Climate-friendly trAnsport) the techno-economical feasibility of different technologies and means to reduce greenhouse gas (GHG) emissions is being analysed for the different modes of transport. This is made in the long-term perspective until 2050, with 2009 as the reference year. This is the report on rail passenger transport, applicable to the European Union (EU-27).The present report has been subject to review among railway experts, representing train suppliers, railway operators as well as academia. They have also responded to a questionnaire. Further, a workshop was held, where the report with assumptions and results was discussed.In the analysis presented in this report it is estimated that a number of efficient improvements that, individually and in combination, are available in order to significantly reduce energy use and the resulting GHG emissions on the rail passenger market until 2050. The analysis has considered different technologies and means:

    – low air drag

    – low train mass

    – energy recovery

    – eco-driving, including traffic flow management

    – space efficiency in trains (increasing payload per metre of train)

    – incremental improvements of energy efficiency, in particular reduced losses.

    Despite anticipated higher average train speeds in the future these combined approaches will, according to the analysis, have the potential to reduce the average specific energy use per passenger-km (pkm) in the order of 45–50 % in the very long term until 2050. As a consequ-ence also the direct and indirect GHG emissions will be reduced. The highest reductions are possible in city and regional rail operations. Reductions are more limited in high-speed opera-tions, because of the advanced technologies already applied. However, high-speed rail has today a comparatively low energy use per passenger-km, partly due to its high average load factor. To be consistent with other work packages of TOSCA, energy use and GHG emissions are measured per passenger-km, assuming representative load factors in different operations.

  • 4.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Casanueva, Carlos
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Rail Systems and Rail Vehicles: Part 2: Rail Vehicles2016 (ed. 1)Book (Other (popular science, discussion, etc.))
    Abstract [en]

    This compendium is mainly intended for MSc education in rail vehicle engineering at KTH Royal Institute of Technology, Stockholm, Sweden. The objective is to give an overview and fundamental knowledge of different rail systems, followed by a more thorough introduction to rail vehicles. In this way most rail aspects are covered. The compendium consists of 20 chapters.

  • 5.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Fröidh, Oskar
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Transport planning, economics and engineering.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Bustad, Tohmmy
    Trafikverket.
    Henrik, Tengstrand
    Bombardier Transportation.
    Green Train: concept and technology overview2014In: International Journal of Rail Transportation, ISSN 2324-8386, Vol. 2, no 1, p. 2-16Article in journal (Refereed)
    Abstract [en]

    Green Train (in Swedish, Gröna Tåget) is a research, development and demonstrationprogramme with the overall objective to define an economical, flexible and environmentallyfriendly train concept. The objective is also to develop technology for futurehigh-speed trains for the northern European market, particularly for Scandinavia. Mostof the technology developed is also applicable to other world markets, as well as toslower trains. The programme has covered many important areas, including economy,capacity and market aspects, conceptual design, traveller attractiveness and interiors,travel time, energy efficiency and noise, winter performance, track friendliness and carbody tilt, aerodynamics, electric propulsion and current collection. The programme hasconducted fundamental analysis and research on the different issues as well as designand testing of new technologies. A number of crucial technologies have undergoneperformance and type testing both in lab and on a test train. Experience feedback wasachieved in commercial train service during the period 2006−2013 including harshwinters. This paper summarises a great deal of research and development that has beenperformed in the Green Train programme.

  • 6.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Lukaszewicz, Piotr
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Energy Consumption and Related Air Pollution for Scandinavian Electric Passenger Trains2006Report (Other academic)
    Abstract [en]

    Energy consumption of a number of modern Scandinavian electric passenger train operations is studied. The trains are X 2000, Regina, OTU (Øresundstoget), Type 71 “Flytoget”and Type 73 “Signatur”. Energy measurements are made in regular train operations inSweden, Denmark and Norway. For Regina and Flytoget long time series (at least oneyear) are available, while shorter time series are available for the other train types. Energydata for new trains (introduced since 1999) are collected in the years 2002-2005. Energydata from 1994 are used for X 2000 and are corrected for operational conditions of 2004.For comparison, energy data for an older loco-hauled train of 1994 is also used.In the present study energy consumption for propulsion, on-board comfort and catering, aswell as idling outside scheduled service, is determined. The energy consumption includeslosses in the railway’s electrical supply, i.e. the determined amount of energy is as suppliedfrom the public electrical grid.Emissions of air pollutants, due to production of the electric energy used, are alsodetermined, in this case CO2, NOx, HC and CO. Three alternative determinations are made:(1) Pollution from average electric energy on the common Nordic market;(2) Pollution from “Green” electric energy from renewable sources;(3) Marginal contribution for an additional train or passenger, short-term and long-term.The newly introduced EU Emissions Trading Scheme with emission allowances willmost likely limit the long-term emissions independently of the actual amount ofelectric energy used by electric trains.It is shown that the investigated modern passenger train operations of years 2002- 2005 usea quite modest amount of energy, in spite of the higher speeds compared with trains of1994. For comparable operations the energy consumption is reduced by typically 25 – 30 %per seat-km or per passenger-km if compared with the older loco-hauled trains. The reasonsfor the improved energy performance are:(1) Improved aerodynamics compared with older trains (reduced air drag);(2) Regenerative braking (i.e. energy is recovered when braking the train);(3) Lower train mass per seat;(4) Improved energy efficiency in power supply, partly due to more advancedtechnologies of the trains.Energy consumption per passenger-km is very dependent of the actual load factor (i.e. ratiobetween the number of passenger-km and the offered number of seat-km). For longdistance operations load factors are quite high, typically 55 - 60 % in Scandinavia. In thismarket segment energy consumption is determined to around 0.08 kWh per pass-km. Forfast regional services with electric trains, the load factors vary from typically 20 to about40 %, while the energy consumption varies from 0.07 kWh per pass-km (for the highestload factor) to 0.18 kWh/pass-km.However, also in the latter cases the investigated trains are very competitive to other modesof transport with regard to energy consumption and emissions of air pollutants.

  • 7.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Orvnäs, Anneli
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Persson, Rickard
    On the Optimization of a Track-Friendly Bogie for High Speed2009In: 21st International Symposium on Dynamics of Vehicles on Roads and Tracks, IAVSD'09, Stockholm, August 17-21, 2009., 2009Conference paper (Other academic)
    Abstract [en]

    When designing and optimizing a rail vehicle there is a contradiction between, on the one hand, stability on straight track at high speed and, on the other hand, reasonable wheel and rail wear in small- and medium radius curves. Higher speeds require to some extent stiffer wheelset guidance to avoid hunting and ensure stability. However, with stiffer wheelset guidance the risk of increased wheel and rail wear in curves is imminent. In this paper, the process of developing and optimizing a track-friendly bogie is described. A multi-body system (MBS) simulation model was used, taking due consideration to nonlinearities in suspension and wheel-rail contact, as well as realistic flexibilities in the track. Adequate and systematic consideration is taken to a wide range of possible non-linear wheel-rail combinations. Dynamic stability is investigated both on straight track and in wide curves at high speeds. The balance between flange wear and tread wear is studied in order to maximize wheel life between re-profiling operations in the intended average operation. The result is a bogie with relatively soft wheelset guidance allowing passive radial self-steering, which in combination with appropriate yaw damping ensures stability on straight track at higher speeds. The bogie has been subject to both certification testing and long-term service testing in the Gröna Tåget (the Green Train) research and development programme.

  • 8.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Orvnäs, Anneli
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Persson, Rickard
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Radial self-steering bogies - Development, advantages and limitations2007In: ZE Vrail - Glasers Annalen: Zeitschrift fuer das gesamte System Bahn, ISSN 1618-8330, Vol. 131, no Suppl., p. 248-259Article in journal (Refereed)
    Abstract [en]

    Considering the total cost of railway operations, It is important to reduce the deterioration caused to the track by rail vehicles and vice versa. Radial steering running gear, where the wheelsets take up approximate radial positions in curves, is an important mean of reducing rail and wheel wear. They also allow curves to be negotiated at higher lateral acceleration on non-perfect track, without exceeding stipulated limits for lateral track shift forces. In order to run dynamically stable at high speed, the damping of the bogie must be appropriate, in particular the yaw damping between bogies and car body. Since the mid-1970's radial self-steering bogles have been developed and used in about 1 200 passenger rail vehicles in Scandinavia. This development continues and during 2006 a test train with radial self-steering bogies is run in speeds up till 281 km/h as part of the Swedish R&D program "GrönaTå get" (GreenTrain). Although there are limitations in the performance of passively self-steering bogles they are a simple and proven solution. Ultimately, In the future actively controlled radial steering may be considered asan appropriate mean to achieve higher performance and track-friendliness.

  • 9.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Orvnäs, Anneli
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Persson, Rickard
    Radial Self-Steering Bogies: Recent Developments for High Speed2009In: 7th International Conference on Railway Bogies and Running Gears / [ed] István Zobory, 2009, p. 63-72Conference paper (Other academic)
    Abstract [en]

    Considering the total cost of railway operations, it is important to reduce the deterioration caused to the track by rail vehicles and vice versa. Radial steering running gear, where the wheelsets take up approximate radial positions in curves, is an important mean of reducing rail and wheel wear. They also allow curves to be negotiated at higher lateral acceleration on non-perfect track, without exceeding stipulated limits for lateral track shift forces. In order to run dynamically stable at high speed, the damping of the bogie must be appropriate, in particular the yaw damping between bogies and carbody. Radial self-steering bogies are used on more than 1200 rail passenger vehicles in Scandinavia since the early 1980’s. The maximum service speed of these vehicles ranges up to 210 km/h. Ongoing development seems to confirm that the use of such bogies can be extended into the very high-speed area of at least 250 km/h. There has previously been some scepticism on the feasibility of soft wheelset guidance for higher speeds, in particular with respect to running stability. Although there are some limitations in the performance of radial self-steering bogies, this solution is robust and well-proven since about 25 years. The ultimate future may be a mechatronic bogie, where the wheelsets are guided in the most optimal way through controlled and forced radial steering. Such bogies may be justified if performance is out of the possible range of passive self-steering solutions.

  • 10.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Gröna Tåget - Green Train - Train for tomorrow's travellers2011In: ZEVrail, ISSN 1618-8330, Vol. 135, p. 140-153Article in journal (Other academic)
    Abstract [en]

    Gröna Tåget (Green Train) is a Swedish research and development programme aiming at defining a concept and developing technology for the next generation high-speed trains, suitable for the Northern European countries. The programme involves almost all major stakeholders in the railway business in Sweden. Main sponsors are Trafikverket (former Banverket) as well as the railway industry and operators (Bombardier, SJ and others). The total budget is around 15 million EUR. The technical coordination is with the Royal Institute of Technology (KTH) in Stockholm. The program started in 2005 and will continue until the end of 2011.

    Gröna Tåget is intended to be a fast, track-friendly, electric tilting train that can not only maintain higher speeds than conventional trains on sections with curves, but special versions could allow 300 km/h or more on future dedicated high-speed lines. Gröna Tåget shall be more attractive and more cost effective both to travellers and to operators than today’s trains. Environmental perfor­mance (energy use per passenger, noise) is expected to be still better than existing trains at lower speed. 

  • 11.
    Andersson, Evert
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Öberg, J.
    Models for infrastructure costs related to the wheel-rail interface2009In: Wheel-Rail Interface Handbook, Woodhead Publishing Limited, 2009, p. 608-629Chapter in book (Refereed)
    Abstract [en]

    A model for determination of costs for track deterioration is presented. In particular, the model is able to discriminate between vehicles with different characteristics operating on the track, as well as incorporating operating data (speed, cant deficiency, etc.) and track geometry. The model is implemented in an Excel™ environment. Its use is exemplified by a Swedish case of mainline passenger and freight traffic. Some results are presented on the influence of vehicle characteristics, track geometry, track lubrication and speed. The model predicts that axle load, radial steering ability, unsprung mass and track lubrication are decisive for track deterioration and its associated costs.

  • 12.
    Berg, Mats
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Stensson Trigell, AnnikaKTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Selected and extended papers from the 21st symposium of the International Association of Vehicle System Dynamics: held at the Royal Institute of Technology (KTH), Stockholm, Sweden, August 17-21, 20092010Conference proceedings (editor) (Refereed)
  • 13.
    Berg, Mats
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Stensson Trigell, AnnikaKTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Special Issue: State of the Art Papers of the 21st IAVSD Symposium2009Conference proceedings (editor) (Refereed)
  • 14. Bhiwapurkar, M. K.
    et al.
    Saran, V. H.
    Harsha, S. P.
    Goel, V. K.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Effect of magnitudes and directions (mono-axis and multi-axis) of whole body-vibration exposures and subjects postures on the sketching performance2011In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 225, no F1, p. 71-83Article in journal (Refereed)
    Abstract [en]

    Whole-body vibrations in trains are known to affect the performance of sedentary activities such as reading, writing, sketching, working on a computer, etc. The objective of the study was to investigate the extent of disturbance perceived in sketching task by seated subjects in two postures under mono-and multi-axis Gaussian random vibration environment. The study involved 21 healthy male subjects in the age group of 23-32 years. Random vibrations were generated both in mono-and multi-axial directions in the frequency range of 1-10 Hz at 0.5, 1.0, and 1.5 m/s(2) rms (root mean square) amplitude. The subjects were required to sketch given geometric figures such as a circle, triangle, rectangle, and square with the help of ball-point pen under given vibration stimuli in two postures (sketch pad on lap and sketch pad on table). The deviation in distortion with respect to the given figure is represented in terms of percentage distortion. The influence of vibrations on the sketching activity was investigated both subjectively and by two specifically designed objective methods, namely, RMS (root mean square methodology) and area methods. The judgements of perceived difficulty to sketch were rated using seven-point semantic judgement scale. The percentage distortion and difficulty in sketching activity increased with an increase in vibration magnitude. Both subjective evaluation and the RMS method revealed that the task was affected more while sketching on the table. The percentage distortion was affected similarly and maximum in all the vibration directions except for the vertical, while sketching difficulty was found to be higher only with longitudinal and multi-axis vibration direction. The subjective evaluation also revealed that there was no effect of the type of entity chosen on the sketching difficulty.

  • 15. Bhiwapurkar, M. K.
    et al.
    Saran, V. H.
    Harsha, S. P.
    Goel, V. K.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Influence of Mono-axis Random Vibration on Reading Activity2010In: Industrial Health, ISSN 0019-8366, E-ISSN 1880-8026, Vol. 48, no 5, p. 675-681Article in journal (Refereed)
    Abstract [en]

    Recent studies on train passengers' activities found that many passengers were engaged in some form of work, e.g., reading and writing, while traveling by train. A majority of the passengers reported that their activities were disturbed by vibrations or motions during traveling. A laboratory study was therefore set up to study how low-frequency random vibrations influence the difficulty to read. The study involved 18 healthy male subjects of 23 to 32 yr of age group. Random vibrations were applied in the frequency range (1-10 Hz) at 0.5, 1.0 and 1.5 m/s(2) rms amplitude along three directions (longitudinal, lateral and vertical). The effect of vibration on reading activity was investigated by giving a word chain in two different font types (Times New Roman and Anal) and three different sizes (10, 12 and 14 points) of font for each type. Subjects performed reading tasks under two sitting positions (with backrest support and leaning over a table). The judgments of perceived difficulty to read were rated using 7-point discomfort judging scale. The result shows that reading difficulty increases with increasing vibration magnitudes and found to be maximum in longitudinal direction, but with leaning over a table position. In comparison with Times New Roman type and sizes of font, subjects perceived less difficulty with Anal type for all font sizes under all vibration magnitude.

  • 16.
    Brabie, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Andersson, Evert
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Analysis of vehicle features influencing train derailment processes and consequences2008In: ZEVrail Glasers Annalen, ISSN 1618-8330, Vol. 132, p. 172-184Article in journal (Refereed)
  • 17.
    Brabie, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Andersson, Evert
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    High-Speed Train Derailments: Minimizing Consequences through Innovative Design2008In: Proceedings of the World Congress of Railway Research (WCRR'08), 2008Conference paper (Refereed)
    Abstract [en]

    In the current paper, various possibilities of minimizing consequences of high-speed rail vehiclederailments have been studied through a combination of empirical observations and multi bodysystem (MBS) simulations. In order to assess the appropriate measures and features for an increasedderailment-worthy design, a comprehensive MBS model is developed to predict the pre and postderailmentvehicle behaviour. Preventing wheel flange climbing derailment after axle journal failureson curved track is accomplished by implementing mechanical restrictions in the bogie frame. Threealternative substitute guidance mechanisms are presented and a systematic feasibility analysis forone of them, a low-reaching axle journal box, is presented. Three conventionally coupled passengertrailing cars are investigated after derailments on tangent and curved track as a function of themaximum centre coupler yaw angle, carbody height of centre of gravity, coupler and bogie transversalbeam height. Furthermore, the articulated train concept is investigated as a function of different intercarbodydamper characteristics.

  • 18.
    Brabie, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Andersson, Evert
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Means of Minimizing Post-Derailment Consequences by Alternative Guidance Mechanisms2007In: Proceedings of the 7th International Conference on Railway Bogies and Running Gears (BOGIE'07), 2007, p. 303-310Conference paper (Refereed)
  • 19.
    Brabie, Dan
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Andersson, Evert
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Post-derailment dynamic simulation of rail vehicles: Methodology and applications2008In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 46, no Suppl. S, p. 289-300Article in journal (Refereed)
    Abstract [en]

    An earlier developed multi-body system post-derailment module. that predicts the wheelsets' behaviour after impact with concrete sleepers, is upgraded to account for possible wheel-rail fastener impact after train derailments at high speed. The vertical stiffness describing the wheel-fastener impact behaviour is calibrated and validated based on two authentic derailment cases. Geometrical specifications that permit it brake disc and a bogie frame to act as substitute guidance mechanisms after Hart e climbing derailments on Curved track are presented for an X 2000 trailer car. Further, an introductory analysis on the post-derailment vehicle behaviour on tangent track after a 'flange on rail head' derailment condition is also presented its a function of bogie yaw resistance. The risk of carbody overturning after derailments on tangent track is assessed as a function of coupler height and carbody centre of gravity as well as bogie transversal beam position.

  • 20. Bruni, Stefano
    et al.
    Vinolas, Jordi
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Polach, Oldrich
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Modelling of suspension components in a rail vehicle dynamics context2011In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 49, no 7, p. 1021-1072Article in journal (Refereed)
    Abstract [en]

    Suspension components play key roles in the running behaviour of rail vehicles, and therefore, mathematical models of suspension components are essential ingredients of railway vehicle multi-body models. The aims of this paper are to review existing models for railway vehicle suspension components and their use for railway vehicle dynamics multi-body simulations, to describe how model parameters can be defined and to discuss the required level of detail of component models in view of the accuracy expected from the overall simulation model. This paper also addresses track models in use for railway vehicle dynamics simulations, recognising their relevance as an indispensable component of the system simulation model. Finally, this paper reviews methods presently in use for the checking and validation of the simulation model.

  • 21. Bucca, Giuseppe
    et al.
    Carnevale, Marco
    Collina, Andrea
    Facchinetti, Alan
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jönsson, Per-Anders
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Adoption of different pantographs' preloads to improve multiple collection and speed up existing lines2012In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 50, no SUPPL. 1, p. 403-418Article in journal (Refereed)
    Abstract [en]

    The current collection using more than one pantograph is needed in railway operation to provide power to non-electrically connected traction units and, in some cases, to reduce current density on the collector strips that heavily influences the wear on the contacting bodies. The multiple current collection may become a critical condition due to the mechanical disturbances produced on the trailing pantographs by the interaction between the first pantograph and the catenary. The present-day evolution of pantograph preload regulating systems, exploiting pressure-controlled servo-valves driven by electronic units, allows a diversification of the preloads of front and rear pantographs. In this work, a suitable solution to improve multiple pantograph collection quality is analysed by the use of a lower mean force on the leading pantograph aimed at reducing the oscillations of contact wire the trailing pantograph is subjected to. This would improve the current collection quality of the trailing pantograph, and could be pursued even admitting a slight worsening of front pantograph's performances.

  • 22. Bucca, Guiseppe
    et al.
    Carnevale, Marco
    Collina, Andrea
    Facchinetti, Alan
    Drugge, Lars
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Vehicle Dynamics.
    Jönsson, Per-Anders
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group. KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Differentiation of pantographs’ preloads as a mean to improve multiple collection and speed upexisting lines2011In: Proceedings of 22nd Symposium of the International Association for Vehicle System Dynamics / [ed] Simon Iwnicki, 2011Conference paper (Refereed)
  • 23.
    Burgelman, Nico
    et al.
    TU Delft.
    Sichani, Matin
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering.
    Li, Zili
    TU Delft.
    Dollevoet, R
    TU Delft.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Comparison of wheel/rail contact models applied for online vehicle dynamic simulation2013Conference paper (Refereed)
  • 24.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Alonso, Asier
    CEIT and Tecnun, University of Navarra.
    Eziolaza, Ibon
    CAF I+D.
    Giménez, José Germán
    CAF I+D and Tecnun, University of Navarra.
    Dynamic instability of railway vehicles with flexible wheelsets and varaible gauge: Estabilidad Dinámica en Vehículos con Ejes Flexibles y Ancho Variable2011In: First European Forum on Railway Running Gears. Madrid. 7-9 June 2011, 2011Conference paper (Other academic)
  • 25.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, VinnExcellence Center for ECO2 Vehicle design.
    Alonso, Asier
    Department of Applied Mechanics, CEIT, Donostia-San Sebastián, Spain.
    Giménez, José Germán
    TECNUN, University of Navarra, Donostia-San Sebastián, Spain.
    Influence of Bearing Flexibility in Rail Vehicle Dynamics2015In: The international Journal of railway technology, ISSN 2049-5358, E-ISSN 2053-602X, Vol. 4, no 1, p. 47-67Article in journal (Refereed)
    Abstract [en]

    Dynamic multibody models for railway vehicles usually assume that the stiffness of the bearings is much higher than that of the primary suspension, neglecting their effect whatsoever. This assumption might not be entirely valid for high speed vehicles, where the primary suspension is stiffer than other rail vehicles; or for more complex systems such as variable gauge wheelsets, where the whole mechanic system might have a higher than expected flexibility. In this paper, a model to obtain the stiffness of a typical configuration of railway bearings is developed and applied to both a high speed vehicle bearing set and a variable gauge wheelset bearing set. The results show that the reduction of lateral stiffness as a result of bearing flexibility can reach up to 35% of its theoretical value. This massive reduction has a major influence on the prediction of the dynamic behaviour of these vehicles, e.g. critical speed or curving performance.

  • 26.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Alonso, Asier
    CEIT and Tecnun, University of Navarra.
    Giménez, José Germán
    CAF I+D and Tecnun, University of Navarra.
    The Influence of Bearing Flexibility on High Speed Vehicles2012In: Proceedings of the First International Conference on Railway Technology: Research, Development and Maintenance / [ed] J. Pombo, Stirlingshire, UK: Civil-Comp Press , 2012, p. Paper 25-Conference paper (Refereed)
    Abstract [en]

    Railway multibody models usually ignore the flexibility of the rolling bearings, assuming that it is much smaller than the flexibility of the primary suspension elements. However, this assumption is not necessarily valid for high speed vehicles, which have a much stiffer primary suspension. In this paper a model to obtain the stiffness parameters of a typical configuration of railway bearings is developed and applied to a high speed vehicle bearing system.

    In this paper a bearing model has been developed, which takes into account the real geometry of the bearings and races for a more precise calculation of the forces transmitted through the different contact patches.

    It has been demonstrated that the interaction of rollers and races can never be considered as Hertzian contact, as the shape of the contact area goes from ellipsoidal to trapezoidal as the load increases, including a mixed contact shape when only one of the roller end is in contact with the race. Hertzian contact implies a unique type of contact through all the loading cases, with a loss of precision in the areas where it does not behave in this way. The methodology has been applied to a bearing set used in high speed vehicles, with the following results:

    1. The stiffness matrix of the bearing set has been obtained. Individual stiffness values are highly dependent on the mounting clearance. A priori, this dependence cannot be neglected for high speed dynamic analyses.
    2. The inclusion of bearing stiffness in a high speed vehicle can affect the theoretical values of the primary suspension, i.e. reduce longitudinal stiffness up to 10% or lateral stiffness up to 32%. This effect will decrease the dynamic stability of the vehicle.
    3. It can also affect the transmission of the lateral force, displacing the lateral force position closer to the wheelset axis. This effect, which is positive for the dynamic behaviour of the vehicle, is negligible for the stiffness values of the primary suspension and the bearing set of the studied vehicle.

    Moreover, a polyvalent and adaptable bearing model has been developed that allows the calculation of various characteristics and variables. This model can be further used for other studies that need individual roller characteristics, such as contact geometry or maximum pressures in the races.

  • 27.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Dirks, Babette
    Bombardier Transportation Sweden.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Bustad, Tohmmy
    Trafikverket.
    Track damage prediction for Universal Cost Model applications2017In: Proceedings of the 25th IAVSD Symposium on Dynamics of Vehicles on Roads and Tracks, CRC Press, 2017Conference paper (Other academic)
    Abstract [en]

    In the EU project Roll2Rail, a Universal Cost Model (UCM) is developed, where innovations in running gear can be analysed within a simplified Life Cycle Cost (LCC) frame- work regarding its impact in energy, noise, vehicle damage and track damage. In this paper we describe the developed methodology for track damage calculation, demonstrate a study case for a regional train, and extrapolate the differential costs of different vehicle technologies in infra- structure. The results and implementation of the damage calculation methods are discussed, and the benefits of a unified methodology for a wide range of stakeholders are presented. 

  • 28.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Dirks, Babette
    Bombardier Transportation.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Hossein Nia, Saeed
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Shazamanian Shichani, Matin
    MiW Rail Technilogy.
    Integrated simulation of damage: efficient contact modeling, wear-RCF interaction, and long-term evolution2016In: ICRI Workshop on Wear and RCF, 2016Conference paper (Other academic)
  • 29.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Doulgerakis, Emmanouil
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Jönsson, Per-Anders
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Influence of switches and crossings on wheel profile evolution in freight vehicles2014In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 52, no SI, p. 317-337Article in journal (Refereed)
    Abstract [en]

    Wheel reprofiling costs for freight vehicles are a major issue in Sweden, reducing the profitability of freight traffic operations and therefore hindering the modal shift needed for achieving reduced emissions. In order to understand the damage modes in freight vehicles, uniform wear prediction with Archard's wear law has been studied in a two-axle timber transport wagon, and simulation results have been compared to measurements. Challenges of wheel wear prediction in freight wagons are discussed, including the influence of block brakes and switches and crossings. The latter have a major influence on the profile evolution of this case study, so specific simulations are performed and a thorough discussion is carried out.

  • 30.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. Bombardier Transportation, Swedem.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Comparison of wear prediction models for different contact conditions2016In: Proceedings of the 24th Symposium of the International Association for Vehicle System Dynamics (IAVSD 2015), Graz, Austria, 17-21 August 2015 / [ed] Martin Rosenberger, Manfred Plöchl, Klaus Six, and Johannes Edelmann, CRC Press, 2016, p. 871-878Conference paper (Refereed)
    Abstract [en]

     Simulation of wheel and rail wear allows to predict long term profile evolution and thus, study the consequences of wheel damage in the dynamic behaviour of the vehicle, or study future maintenance requirements. Several models have been developed which try to solve the wear issue by relating the energy dissipated in the wheel-rail contact to the worn out material, from which two can be highlighted (Tg/A and Archard) which have significant differences on contact level. Even though, the prediction of long term wheel profile evolution has been validated with these two models, which means that for regular applications they seem to have an equivalent behaviour. In this work similarities and differences between the long term wear prediction methodologies are analysed, discussing their actual limitations. Then, these differences are exploited in specific operational cases to compare their wear prediction performance.

  • 31.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Jönsson, Per-Anders
    Tikab Strukturmekanik AB.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    influence of switches and crossings on wheel profile evolution in freight vehicles2013In: Proceedings of the 23nd IAVSD Symposium on Dynamics of Vehicles on Roads and Tracks / [ed] Simon Iwnicki, Taylor & Francis, 2013Conference paper (Refereed)
  • 32.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Jönsson, Per-Anders
    Tikab Strukturmekanik AB.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Uniform Wheel Wear of a Two Axle Freight Vehicle with Friction Dampers2012In: Proceedings of the First International Conference on Railway Technology: Research, Development and Maintenance / [ed] J. Pombo, Stirlingshire, UK: Civil-Comp Press , 2012, p. Paper 93-Conference paper (Refereed)
    Abstract [en]

    Wheel reprofiling accounts for a considerable amount of the maintenance costs forfreight wagons in Sweden, and the causes can be divided mainly in three groups:wheel flats, shelling and uniform wear. In this paper the development of uniformwheel wear in a two-axle freight vehicle is studied. This wagon with Unitruckrunning gear had a major modification in the suspension elements in 2005 whichhighly reduced flange wear. The method developed at KTH for uniform wearcalculation is applied on both old and new simulation models. The influence offreight wagon specific characteristics on the wear development is also analysed, i.e.high axle load and friction damping elements.

  • 33.
    Casanueva, Carlos
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Jönsson, Per-Anders
    Tikab Strukturmekanik AB.
    Stichel, Sebastian
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Use of Archard's wear law for the calculation of uniform wheel wear of high tonnage freight vehicles2013In: Proceedings of the 1st Joint Rail Conference: JRC2013, ASME Press, 2013, p. JRC2013-2545-Conference paper (Refereed)
    Abstract [en]

    Wheel profile evolution has a large influence on track and wheelset related maintenance costs. It influences important parameters such as equivalent conicity or contact point positioning, which will affect the dynamic behavior of the vehicle, in both tangent track and curve negotiation. High axle loads in freight wagons may increase both the wheel wear and the damage caused by vehicles with both new and already worn profiles. A common profile in Europe is the S1002 profile, developed for rail inclination 1/40. In Sweden rail inclination is 1/30, so contact conditions might not be optimal. The presented work uses Archard’s wear law to analyze the profile wear evolution in a two axle freight vehicle with Unitruck running gear on the Swedish network. This wear calculation methodology has been successfully used to predict uniform wear in passenger vehicles. First, the vehicle model has been optimized in order to improve the speed of the wear simulations. Experimental measurements of wheel profiles have been performed in order to validate the simulations. The conclusion is that the wear methodology successfully used to predict uniform wheel wear in passenger vehicles cannot be directly applied for the calculation of wheel profile evolution in high tonnage freight vehicles. The influence of block brakes or switches and crossings cannot be dismissed when calculating uniform wheel wear in these cases.

  • 34.
    Chaksoong, Kitiphat
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Effects of Curving of a SRT Passenger Coach with SRT Vidura Wheel Profile and BS100A Rail on Wheel Wear and Wear Energy Dissipation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This work presents the study of wheel wear due to curving of a particular type of the state Railway of Thailand (SRT) passenger coach at various radii of curvature with SRT Vidura Wheel and BS100A rail profile (1:40 inclination) on a meter gauge track utilized by SRT. The tendency of wheel wear due to the different curve radii of both outer wheel and inner wheel of each wheel profile and the wear energy dissipation are studied. In addition, the ratio of lateral to vertical wheel rail forces in the presence of various friction conditions is investigated. This study utilized a GENSYS simulation software in modelling of the railway vehicle which is one of the best in railway industry. From the simulation with running distance of 14 km, it is found that the wheel wear at various radii of curvature is divided into three groups according to curve radius, 160-200, 300-400 and 500-3000 meter. The maximum wheel wear is at the curve radius of 300 meter and occurs at the outer wheel rather than at the inner wheel. The smaller curve radius contributed to the high wear energy dissipation due to larger angle of attack and high longitudinal stiffness of the bogie. The increasing coefficient of friction provided the higher values of Y/Q where the value of Y/Q exceeded Nadal’s limit for 0.5 coefficient of friction value that could start wheel flange climbing of the outer wheel so that a wheel flange should be lubricated to prevent derailment.

  • 35.
    Dirks, Babette
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Simulation and Measurement of Wheel on Rail Fatigue and Wear2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    The life of railway wheels and rails has been decreasing in recent years. This is mainly caused by more traffic and running at higher vehicle speed. A higher speed usually generates higher forces, unless compensated by improved track and vehicle designs, in the wheel-rail contact, resulting in more wear and rolling contact fatigue (RCF) damage to the wheels and rails. As recently as 15 years ago, RCF was not recognised as a serious problem. Nowadays it is a serious problem in many countries and ''artificial wear'' is being used to control the growth of cracks by preventive re-profiling and grinding of, respectively, the wheels and rails.  This can be used because a competition exists between wear and surface initiated RCF: At a high wear rate, RCF does not have the opportunity to develop further. Initiated cracks are in this case worn off and will not be able to propagate deep beneath the surface of the rail or wheel.

    When wheel-rail damage in terms of wear and RCF can be predicted, measures can be taken to decrease it. For example, the combination of wheel and rail profiles, or the combination of vehicle and track, can be optimised to control the damage. Not only can this lead to lower maintenance costs, but also to a safer system since high potential risks can be detected in advance.

    This thesis describes the development of a wheel-rail life prediction tool with regard to both wear and surface-initiated RCF. The main goal of this PhD work was to develop such a tool where vehicle-track dynamics simulations are implemented. This way, many different wheel-rail contact conditions which a wheel or a rail will encounter in reality can be taken into account.

    The wear prediction part of the tool had already been successfully developed by others to be used in combination with multibody simulations. The crack prediction part, however, was more difficult to be used in combination with multibody simulations since crack propagation models are time-consuming. Therefore, more concessions had to be made in the crack propagation part of the tool, since time-consuming detailed modelling of the crack, for example in Finite Elements models, was not an option. The use of simple and fast, but less accurate, crack propagation models is the first step in the development of a wheel-rail life prediction model.

    Another goal of this work was to verify the wheel-rail prediction tool against measurements of profile and crack development. For this purpose, the wheel profiles of trains running on the Stockholm commuter network have been measured together with the crack development on these wheels. Three train units were selected and their wheels have been measured over a period of more than a year. The maximum running distance for these wheels was 230,000 km.

    A chosen fatigue model was calibrated against crack and wear measurements of rails to determine two unknown parameters.  The verification of the prediction tool against the wheel measurements, however, showed that one of the calibrated parameters was not valid to predict RCF on wheels. It could be concluded that wheels experience relatively less RCF damage than rails. Once the two parameters were calibrated against the wheel measurements, the prediction tool showed promising results for predicting both wear and RCF and their trade-off. The predicted position of the damage on the tread of the wheel also agreed well with the position found in the measurements.

  • 36.
    Dirks, Babette
    et al.
    Bombardier Transportation Sweden.
    Casanueva, Carlos
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Bustad, Tohmmy
    Trafikverket.
    Wheel damage prediction for Universal Cost Model applications2017In: Proceedings of the 25th IAVSD Symposium on Dynamics of Vehicles on Roads and Tracks, CRC Press, 2017Conference paper (Other academic)
    Abstract [en]

    In the EU project Roll2Rail, a Universal Cost Model (UCM) is developed, where innovations in running gear can be analysed within a simplified Life Cycle Cost (LCC) framework regarding its impact on energy, noise, vehicle damage and track damage. In this paper, the developed methodology for wheel damage calculation will be described. Besides, it will demonstrate different study cases for a regional train and extrapolate the differential LCC of different infrastructure parameters and vehicle technologies. Both the results and the implementation of the damage calculation methods are discussed, and the benefits of a unified methodology for a wide range of stakeholders are presented.

  • 37.
    Dirks, Babette
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. Bombardier Transportation, Passengers Division - Specialist Engineering, Sweden .
    Development of a fatigue damage model by using eddy current measurements of the Swedish iron ore railway2012In: 9th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, CM 2012, 2012, p. 547-549Conference paper (Refereed)
  • 38.
    Dirks, Babette
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Prediction model for wheel profile wear and rolling contact fatigue2009In: 8th International Conference on Contact Mechanics and Wear of Rail/Wheel Systems, 2009Conference paper (Refereed)
    Abstract [en]

    A lifetime prediction tool for railway wheels and rails should be able to predict both wear and rolling contact fatigue (RCF), which are the two main deterioration phenomena. Several models exist to predict wear or RCF, but not that many models exist which can predict both. In this study, two of these RCF prediction models have been extended. The performance of these models has been studied through a parametric study where multi-body simulations (MBS) provided the input to the models. The influences of several parameters which can have an effect on the wheel/rail life have been studied in order to find the behavior of the different models. These parameters are: curve radius, worn wheel and rail profiles, coefficient of friction, primary stiffness, track irregularities, and cant deficiency.  This paper describes the differences between the two models and shows that the adjustments of the models have a significant influence on RCF prediction.

  • 39.
    Dirks, Babette
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    Bombardier Transportation, Passengers Division - Specialist Engineering, Västerås, Sweden.
    Prediction model for wheel profile wear and rolling contact fatigue2011In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 271, no 1-2, p. 210-217Article in journal (Refereed)
    Abstract [en]

    A lifetime prediction tool for railway wheels and rails should be able to predict both wear and rolling contact fatigue (RCF), which are the two main deterioration phenomena. Several models exist to predict wear or RCF, but not many models exist which can predict both. In this study, two of these RCF prediction models have been extended. The performance of these models has been studied through a parametric study where multi-body simulations (MBS) provided the input to the models. The influences of several parameters which can have an effect on the wheel/rail life have been studied in order to find the behaviour of the different models. These parameters are: curve radius, worn wheel and rail profiles, coefficient of friction, primary stiffness, track irregularities, and cant deficiency. This paper describes the differences between the two models and shows that the adjustments of the models have a significant influence on RCF prediction.

  • 40.
    Dirks, Babette
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Prediction of wheel profile wear and rolling contact fatigue for the Stockholm commuter train2010In: 16th International Wheelset Congress, 2010Conference paper (Other academic)
    Abstract [en]

    Although several models exist to predict rolling contact fatigue (RCF) or wear, only a few models exist which can predict both. RCF and wear interact with each other, therefore a model has to be developed that can calculate both RCF and wear in order to get a lifetime prediction tool for railway wheels and rails. In this study, vehicle dynamics simulations were performed with the models of two different vehicle types running on the Stockholm commuter network. The performance of these vehicles has been studied with respect to wear and RCF by importing the output from the vehicle dynamics simulations into different wear and RCF models. The performance of these prediction models has also been studied. The influences of several parameters on the behavior of both the vehicles and the prediction models were studied. The results show that not only the vehicles behave differently, but also the wear and RCF prediction models. 

  • 41.
    Dirks, Babette
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. Bombardier Transportation, Sweden .
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Prediction of wheel profile wear and crack growth - comparisons with measurements2016In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 366, p. 84-94Article in journal (Refereed)
    Abstract [en]

    A model which can predict the length of the surface crack and crack depth in rails was developed in a previous study by the authors B. Dirks, R. Enblom, A. Ekberg, M. Berg (2015) []. In the present study, verification of this crack prediction model in combination with a wear prediction model was done against wheel measurements. For a period of 15 months, the wheels of three units of a Stockholm commuter train were measured with respect to wear and crack development for verification of the wheel life prediction tool. Vehicle-track dynamics simulations were used to calculate the forces and contact positions for the wear and crack prediction models. It can be concluded that the wear prediction model gives reasonable results, especially considering the large scatter in the wheel profile measurements. Although the wheel life prediction tool could not be verified, since the crack prediction model had to be recalibrated for the current wheel application, the results appear promising.

  • 42.
    Dirks, Babette
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. Bombardier Transportation, Sweden.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Prediction of wheel profile wear and crack growth: comparisons with measurementsManuscript (preprint) (Other academic)
  • 43.
    Dirks, Babette
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. Bombardier Transportation, Sweden.
    Ekberg, A.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    The development of a crack propagation model for railway wheels and rails2015In: Fatigue & Fracture of Engineering Materials & Structures, ISSN 8756-758X, E-ISSN 1460-2695, Vol. 38, no 12Article in journal (Refereed)
    Abstract [en]

    Rolling contact fatigue (RCF) and wear of railway wheels and rails are the main phenomena that affect their maintenance costs. When crack propagation and wear rates can be predicted, maintenance planning can be optimised, and cost-effective measures can be developed. Several RCF models exist, but none which can be used in combination with vehicle dynamics simulations and can predict the actual crack depth. This study shows the development of a crack propagation model that can be applied for both railway wheels and rails. Two unknown material parameters in the model were calibrated against crack measurements in a curve on the Dutch railways over a period of 5years. Two different RCF models were used to calculate the stress magnitudes for the propagation model. The propagation model can be used in combination with vehicle-track dynamics simulations and shows promise in predicting the actual crack depth and/or surface length. Further research is needed to determine the model’s validity for other operational conditions.

  • 44. Dominguez, M.
    et al.
    Fernandez, A.
    Cucala, A. P.
    Lukaszewicz, Piotr
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Optimal design of metro automatic train operation speed profiles for reducing energy consumption2011In: Proceedings of the Institution of mechanical engineers. Part F, journal of rail and rapid transit, ISSN 0954-4097, E-ISSN 2041-3017, Vol. 225, no F5, p. 463-473Article in journal (Refereed)
    Abstract [en]

    Trains equipped with automatic train operation (ATO) systems are operated between stations according to the speed commands they receive from balises. These commands define a particular speed profile and running time, with associated energy usage (consumption). The design of speed profiles usually takes into account running times and comfort criteria, but not energy consumption criteria. In this article, a computer-aided procedure for the selection of optimal speed profiles, including energy consumption, which does not have an effect on running times, is presented. To this end, the equations and algorithms that define the train motion and ATO control have been modelled and implemented in a very detailed simulator. This simulator includes four independent modules (ATO, motor, train dynamics, and energy consumption), an automatic generator of every possible profile and a graphical assistant for the selection of speed commands in accordance with decision theory techniques. The results have been compared with measured data in order to adjust and validate the simulator. The implementation of this new procedure in the Madrid underground has led to a 13 per cent of energy saving. As a result, the decision has been taken to redesign all the ATO speed profiles on this underground.

  • 45.
    Doulgerakis, Emmanouil
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Influence of Switches and Crossings on Wheel Wear of a Freight Vehicle2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Turnouts (Switches & Crossings) are important components in railway networks,

    as they provide the necessary flexibility for train operations by allowing trains to

    change among the tracks. But the turnout’s geometry with discontinuity in rail

    profiles and lack of transition curve causes additional wear both on track and on

    vehicle.

    The main goal of this MSc thesis is to investigate the influence of turnouts on wheel

    wear of a freight vehicle. This will be obtained by simulations in the commercial

    MBS software GENSYS. The wheel-rail contact is modelled according to Hertz’s

    theory and Kalker’s simplified theory, with the FASTSIM algorithm, and the wear

    calculations are performed according to Archard’s law.

    Wheel wear is estimated by considering variations in parameters which have effect

    on wheel-rail contact. All these variations are common in daily rail operation, and

    they are caused by it,

    i.e. worn wheel profiles, worn crossing nose and different

    stiffness of the stock and the switch rails at the beginning of the turnout. Moreover,

    the wheel wear is calculated for both possible directions which a vehicle can run,

    the diverging and the straight direction of the turnout. Especially for the straight

    direction, various running speeds have been tested as the speed limit when the

    vehicle follows the straight direction is higher than for the diverging part.

    Running with worn wheel profiles has the greatest impact in terms of increasing the

    wheel wear, especially on the outer part of wheel tread. In addition, the worn crossing

    nose results in increased wheel wear in this area. The results of the simulations

    concerning the different stiffness showed that the wheel wear caused by the contact

    of wheel and stock rail increases whereas the wear caused by the contact with the

    switch rail is kept at about the same level or decreases. It is concluded that turnouts

    have a significant impact on wheel wear, mainly because of the discontinuity in rail

    geometry and all the investigated parameters increase this impact. Moreover, great

    differences in wear values for areas close to each other are observed, mainly because

    of the wear coefficient values chosen in Archard’s wear map.

  • 46.
    Duranton, Coralie
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Fatigue analysis of two wheel‐ mounted brake disc designs2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Due to a need of more compact bogies, the brake discs can be mounted on the railway wheels, bolted through the wheel web. Thus, the wheels are drilled and have multiple areas of contact with the brake discs. To establish maintenance procedures that will be applied to the  wheels,  SNCF  used  the  feedback  from  experience  (as  with  the  train  AGC)  which  gives  perfect  performance  in  terms  of  safety.  However,  to  optimize  the  maintenance  process, numerical  simulations  may  be  preferred  since  they  are  less  conservative.  This  report  describes  the  numerical  simulations,  based  on  the  finite  element  method,  that  were conducted to determine if the Régiolis wheel complies with the standard EN 13979-­‐1 from a mechanical  fatigue  point  of  view.  In  addition,  it  provides  additional  insights  regarding  the  loads and damage suffered by the wheel, which are not taken into account in the standard: the  damage  induced  by  disc  braking  and  the  fretting  that  may  occur  at  the  contact  interfaces. This study has been used as a decision support for the first inspection intervals of the Régiolis wheels.

  • 47.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Deterioration mechanisms in the wheel-rail interface with focus on wear prediction: a literature review2009In: Vehicle System Dynamics, ISSN 0042-3114, E-ISSN 1744-5159, Vol. 47, no 6, p. 661-700Article, review/survey (Refereed)
    Abstract [en]

    Wheel-rail interface management is imperative to railway operation and its maintenance represents a major share of the total maintenance cost. In general, the course of events usually called wear is a complicated process involving several modes of material deterioration and contact surface alteration. Thus material removal or relocation, plastic flow and phase transformation may take place at, just below, or in-between the contacting surfaces. A higher degree of predictability of deterioration mechanisms and a firm basis for optimisation of the wheel-rail system are anticipated to reveal a great potential for cost savings. Wear in the sense of material loss and related wheel-rail profile evolution represents one of several modes of damage. The purpose of this survey is to explore research on wear simulation, to some degree extended to neighbouring disciplines. It is believed that a cross-disciplinary approach involving, for instance, adhesive and abrasive wear, surface plasticity, and rolling contact fatigue opens new perspectives to improved damage prediction procedures.

  • 48.
    Enblom, Roger
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Getting to the root of wheel wear2010In: Railway Gazette International, ISSN 0373-5346, Vol. 166, no 3, p. 35-38Article in journal (Other (popular science, discussion, etc.))
  • 49.
    Enblom, Roger
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Emerging engineering models for wheel/rail wear simulation2005In: Proceedings of the 8th International Conference Railway Engineering, London, June 29-30, 2005, 2005Conference paper (Refereed)
  • 50.
    Enblom, Roger
    et al.
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles. KTH, School of Engineering Sciences (SCI), Centres, The KTH Railway Group.
    Berg, Mats
    KTH, School of Engineering Sciences (SCI), Aeronautical and Vehicle Engineering, Rail Vehicles.
    Impact of non-elliptic contact modelling in wheel wear simulation2008In: Wear, ISSN 0043-1648, E-ISSN 1873-2577, Vol. 265, no 9-10, p. 1532-1541Article in journal (Refereed)
    Abstract [en]

    Advances in simulation of railway wheel wear in the sense of material removal have drawn the attention to the importance of wheel–rail contact modelling. As a further step of enhancing the used simulation procedure in direction of increased generality and reduced need for application-dependent calibration, the focus of this investigation is the influence of non-elliptic contact models on the wheel wear rate and profile shape. To facilitate evaluation the semi-Hertzian contact procedure Stripes, developed by INRETS in France, has been implemented.

    To investigate the capabilities of Stripes to assess the contact area and pressure, shape comparisons have been made with other numerical methods for a set of wheel–rail contact situations. The referenced results are based on the linear elastic half-space assumption, elastic finite element analysis, and elastic–plastic finite element analysis. For reference also the elliptic contact area according to Hertz is shown as given by the contact data table of the multi-body simulation code.

    After exploring the properties of the Stripes procedure with respect to contact area estimation and pressure distribution, the focus is moved to the influence on wear rate, being the principal objective of this investigation. First the wear distribution over the contact patch is studied and compared to results using the elliptic model from the MBS code Gensys and the non-elliptic approach with Kalker's code Contact. Finally the evolution of the wheel profile is simulated for a few typical cases.

    This investigation of wear distributions over non-elliptic patches under different operating conditions indicates significant differences compared to both Contact and the applied Hertzian approach. The expansion from single contact occasions to complete simulations indicates comparable material removal rates but relocation towards the flange side. This tendency is apparent in all of the cases shown, however limited to initial wear in tangent run or reasonably mild curve negotiation.

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