Pdf new developments in the theory of wheelrail contact mechanics. Rail wheel contact problems have been analyzed by applying threedimensional finite element models. Tech rtl for accurate study of the mechanics and dynamics. That means they have a varying diameter at different points of contact. Numerical investigation into the effect of geometric gap. A new solution method for wheelrail rolling contact. Part one provides the fundamentals of contact mechanics, wear, fatigue and lubrication as well as stateoftheart research and emerging technologies related to the wheel rail interface and its management. Beside a standard rail, also a crane rail and a switching component are considered in the verification. Mechanics and fatigue in wheelrail contact 1st edition. Feasibility study for an ultrasonic sensor for monitoring.
Cm2018 1 th international conference on contact mechanics. International journal of vehicle mechanics and mobility volume 45. Wheel rail contact characteristics on a tangent track vs a roller rig rtdf2012 the influence of surface treatment and microstructural parameters on the rail wheel tribological behaviours. Contact mechanics, rolling contact, dynamics, finite element method, stress 1 introduction in studies of railway, wheelrail rolling contact is one of the main issues. Cm2018 1 th international conference on contact mechanics and. High friction at wheel treadrail top contact for locomotives intermediate friction at wheel treadrail top contact especially for freighy cars low friction in wheel flangerail gauge corner contact we can use friction modifiers for this purpose. Cad model of rail wheel contact the cad model of rail wheel contact was saved in. This industrial complex is used today for cultural festivals and activities, but in this case it will be the location for the 11th edition of contact mechanics. Fatigue failures, on the other hand, are more violent in nature and may lead to the breakoff of a large part of the wheel. Contact mechanics analysis of measured wheelrail profiles. The focus of this study is on the development of a stateoftheart singlewheel roller rig for studying contact mechanics and dynamics in railroad applications. This introduction starts in section 1 with a brief overview of fatigue failures of railway wheels. International journal of research in engineering, science and.
The vt roller rig is intended for studying the complex dynamics and mechanics at the wheel rail interface of railway vehicles in a controlled laboratory environment. The influence of these idealisations on contact solution has. Contact mechanics book there are not two round black objects in contact, but that it is actually mickey mouse. Researchers from different countries have been studying the wheelrail contact behavior on turnout switch panels. Applicability of the hertz contact theory to railwheel.
Wheel rail contact mechanics at full scale on the test stand. Rail wheel interaction indian railways institute of. Wheelrail contact mechanics at full scale on the test stand. The trains left wheels now have to travel more than the right wheels because at the turn the track on the left is longer.
The wheelrail contact is critical to the successful operation of a railway network. State of the art roller rig for precise evaluation of wheel. Wheel rail interface handbook is a onestop reference for railway engineering practitioners and academic researchers. Determination of wheelrail contact points in the simulation of railway vehicle dynamics j. Based on these models, the applicability of the hertz contact theory hct to railwheel contact problems is verified in the present paper. This thesis describes the development of a wheel rail life prediction tool with regard to both wear and surfaceinitiated rcf. A new approach to study the wheelrail contact problem in railway dynamics joao pombo, jorge ambrosio. For a fast calculation of vehicletrack dynamics and wheel rail contact mechanics, wheel rail contact geometric gap is usually idealised in elliptic or nonelliptic form. The alteration in wheel and rail profiles due to wear involves considerable vehicle and trackmaintenance costs, and influences the loading capacity of the rails, as well as the operation safety and riding comfort of the vehicles. Basic tribology of the wheelrail contact sciencedirect.
An approximate analysis for hertzian elliptical wheelrail. Wheel rail contact mechanics kevin oldknow director, school of sustainable energy engineering simon fraser university. Wheelrail contact mechanics is one of the fundamental areas for studying wheelrail relationship, therefore, the study of wheelrail contact is of great significance to solve related problems. Wheel rail contact mechanics is one of the fundamental areas for studying wheel rail relationship, therefore, the study of wheel rail contact is of great significance to solve related problems. Such measurements require excellent powering and driving architecture, highperformance motion control, accurate measurements, and relatively noisefree data acquisition systems. In this work the effects of rail vibration absorber on short pitch rail corrugation growth are studied by combining the wheel trackabsorber dynamics, rolling contact mechanics and wear.
The feedback model is simplified to encapsulate the most critical interactions occurring between the wheelrail structural dynamics, rolling contact mechanics and rail wear. A generic wheelrail contact detection formulation is presented here in order to determine online the contact points, even for the most general threedimensional motion of the wheelset. International journal of mechanics and applications 2011. The main goal of this phd work was to develop such a tool where vehicletrack dynamics simulations are implemented. Pdf strength anisotropy of railway wheels under contact. For wheelrail contact, the appearance of conformal or nonconformal contact depends. Effects of rail cant on wheelrail contact forces in slab.
Applicability of the hertz contact theory to rail wheel contact problems article pdf available in archive of applied mechanics 704. Materials used for wheels on rolling stock railway research. Pdf wheelrail contact mechanics at full scale on the test. This issue is studied in papers a and b and will be further discussed in section 5 below. So how do the left wheels travels more than the right wheels without a. To study the influence of interacting wheel and rail profile topology of standard rail uic60, the standard wheel profile as per.
This formulation also allows the study of lead and lag flange contact scenarios, both fundamental for the analysis of potential derailments or for the study. The material used for the railwheel contact is structural steel which isotropic behavior. In general terms, wheel rail contact mechanics is a wide field of study that ranges from overall vehicle dynamics and assessment of global contact forces, to micro mechanics of the surface materials in contact. The 27 contributions succeed in sustaining a balance between mechanics and metallurgy. A change in designed surface topology may result from wear that brings in a wide change in contact geometry and stresses. Wear contact mechanics and wear of railwheel systems. Traditionally, two methods have been used to investigate the railwheel contact, namely hertzs analytical method and kalkers software program contact.
A new wheelrail contact model for railway dynamics. Pdf a new wheelrail contact model for railway dynamics. Firstly, the contact problem between two solid bodies is defined in its general form. Wheelrail interface handbook is a onestop reference for railway engineering practitioners and academic researchers. Contact mechanics and wear of railwheel systems journal of.
On the influence of conformity on wheelrail rolling. Adhesion traction is the friction between the drive wheels and the steel rail. Train wheels are not as simple as they seem awesci. The material used for the rail wheel contact is structural steel which isotropic behavior. It has been widely employed in numerous wheelrail contact mechanics related studies, e. Safety and economy of railway traffic is enormously influenced by the contact stress variation caused by wheel rail contact profile changes. A part of hearst digital media popular mechanics participates in.
Pdf contact mechanics analysis of measured wheelrail profiles. On the influence of conformity on wheelrail rolling contact. P reliminaries fatigue failures of railway wheels applicable, is the in. For a fast calculation of vehicletrack dynamics and wheelrail contact mechanics, wheelrail contact geometric gap is usually idealised in elliptic or nonelliptic form. In the case of a contact between the standard rail. The contact forces developed in the contact are the most important external inputs to the vehicles and the track, and. This way, many different wheel rail contact conditions which a wheel or a rail will encounter in. Influence of rail, wheel and track geometries on wheel and. Pdf a tool has been developed for contact mechanics analysis of the wheelrail contact.
Electromechanical design and development of the virginia tech. The term adhesion railway is only used when there is need to distinguish adhesion railways from railways moved by other means, e. In general terms, wheelrail contact mechanics is a wide field of study that ranges from overall vehicle dynamics and assessment of global contact forces, to micromechanics of the surface materials in contact. A tool has been developed for contact mechanics analysis of the wheel rail contact. Stecco, university of florence, italy abstract the numerical simulation of system dynamics is today a standard in the design. State of the art roller rig for precise evaluation of. Performance analysis of wheel and rail contact by nature of. Modeling of energy processes in wheelrail contacts. A stability analysis on the system yields the growth of weartype rail corrugations over multiple wheelset passages as a function of the passage time delay magnitude. The science of how trains turn without falling off the tracks. Wheel rail profiles and vehicle steering behavior are such that the curve can be considered mild the contact area at each wheel tread low rail interface is approximately circular. The exact position will depend on the wheel and rail profiles and the degree of curvature of the track and whether the wheel is the leading or trailing wheelset on a bogie, as well as other factors determined by the bogie design. A new approach to study the wheelrail contact problem in. Wheelrail contact models for vehicle system dynamics including multipoint.
For numeric simulation, the transient wheelrail rolling contact in railway system is a very complex and timeconsuming process. A simplified model of wheelrail contact mechanics for nonhertzian. Rolling conditions, proceedings of contact mechanics and wear of the wheelrail system, university of. References flange climb derailment criteria and wheelrail. Contact mechanics and wear of railwheel systems journal. Mechanics later needed in treating wheelrail contact. Contact analysis of the two dimensional wheelrail based. Wheel rail engineer for a demonstration of our efforts interest from several other agencies including cta, and mbta in how to better their systems bart wheel rail optimization. This industrial complex is used today for cultural festivals and activities, but in this case it will be the location for the 11th edition of contact. Pdf applicability of the hertz contact theory to rail.
The use of indoorbased simulation tools has become a mainstay in vehicle testing for the automotive and railroad industries. The position of the wheelrail contact, which is typically 1 cm 2 in size, varies continuously as a train progresses down a section of track. Using measurements of wheel and rail profiles as input, the tool is based on the finite element fe code ansys. Based on these models, the applicability of the hertz contact theory hct to rail wheel contact problems is verified in the present paper. Dynamics analysis of wheel rail contact using fea sunil kumar sharmaa, anil kumarb acentre for transportation systems, iit roorkee, uttarakhand, 247667 india. In this paper, simplified two dimensional rigid wheelrail and resilient wheelrail contact finite element models are established, and the reliability of the established models is verified by comparison. Contact analysis of the two dimensional wheelrail based on. A tool has been developed for contact mechanics analysis of the wheelrail contact. Rolling contact stress states of two contact points. Modeling of a roller rig for evaluation of wheelrail contact. Flange climb derailment criteria and wheelrail profile. The feedback model is simplified to encapsulate the most critical interactions occurring between the wheel rail structural dynamics, rolling contact mechanics and rail wear. The contact between wheel and rail is the constitutive element of railway vehicle dynamics.
A generic wheelrail contact detection formulation is presented here in order to determine online the contact points. Part one provides the fundamentals of contact mechanics, wear, fatigue and lubrication as well as stateoftheart research and emerging technologies related to. All the influencing factors have to be taken into account as they interact closely. Some applications in rail vehicle dynamics and wear simulation have been outlined. In studying the wheelrail interaction, the assumptions of conformal contact are justified because of the shape of wheel and rail surfaces.
It is applicable to general nonhertzian contact geometries, and to transient as well as to steady state rolling contact problems. Cad model of railwheel contact the cad model of railwheel contact was saved in. Wheelrail contact mechanics kevin oldknow director, school of. In 1982, at the first contact mechanics and wear of wheelrail system greenwood 3 spotlighted the results of more than 20 years research on the contact of rough surfaces. The geometric or kinematical relations of the wheelrail contact and the contact mechanical relations for the calculation of the contact forces are to. Wheel rail contact characteristics on a tangent track vs a roller rig rtdf2012 extracting summit roughness parameters from random gaussian surfaces accounting for asymmetry of the summit heights. Traditionally, two methods have been used to investigate the rail wheel contact, namely hertzs analytical method and kalkers software program contact. An adhesion railway relies on adhesion traction to move the train. The contact model between wheel and rail is approximated to be elliptical, which is shown to be accurate for the described purpose. Pdf development and advancement in the wheelrail rolling. Simulation and measurement of wheel on rail fatigue and wear. New developments in the theory of wheelrail contact mechanics.
Contact mechanics of railwheel systems ii journal of. International journal of research in engineering, science. Pdf wheelrail contact mechanics at full scale on the. Contact mechanics and wear of railwheel systems cm2006. Jul 01, 2002 the application of contact mechanics to rail profile design and rail grinding the application of contact mechanics to rail profile design and rail grinding magel, eric e. University of waterloo press, 1983 science 600 pages. The contact mechanics between two surfaces was studied by hertz 1882. Effective management of the wheel rail contact is an important aspect of rail infrastructure operations. Contact occurs mainly at the wheel treadrail head and wheel flangerail gauge corner. Railwheel contact problems have been analyzed by applying threedimensional finite element models. In studying the wheel rail interaction, the assumptions of conformal contact are justified because of the shape of wheel and rail surfaces.
Wheelrail contact characteristics on a tangent track vs a roller rig rtdf2012 the influence of surface treatment and microstructural parameters on the railwheel tribological behaviours. Effects of rail cant on wheelrail contact forces in slab tracks. Purchase mechanics and fatigue in wheelrail contact 1st edition. There is clearly a need for information about the wheel rail contact interface in term of position, area, and contact stresses. Request pdf wheelrail contact mechanics the scope of this chapter is the modelling of the force balance at the wheel rail interface in railway vehicles. Wu, a the formation of hollowworn wheels and their effect on wheelrail interaction,a pro ceedings, contact mechanics and wear of railwheel sys tem, the 6th international conference, gothenburg, sweden, june 2003. Reasonable solution method would reduce the computational effort and improve the solution efficiency in a certain extent. Mar 08, 2017 the science of how trains turn without falling off the tracks. Volume 265, issues 910, pages 11491556 30 october 2008 download full issue. Contact department of railway engineering delft university of technology conference website. Proceedings of the 1st international and 16th national conference on machines and mechanisms inacomm20, iit roorkee, india, dec 1820 20 an approximate analysis for hertzian elliptical wheelrail contact problem jay prakash srivastava department of mechanical engineering.
1020 850 1382 121 867 224 603 916 869 762 1610 1516 626 1 808 99 686 840 1136 1408 1338 1451 216 880 568 482 1284 375 611 353 1416 857 608 944 541 614 300 527 825 400 417 1063 43 141 951