Rain water, leaves, and artificial materials may all be present on the railway track. Modeling of energy processes in wheelrail contacts operating. This solves contact problems for wheels on rollers and provides extensions to the contact library. The main goal of this thesis was to clarify the effect of the applied quantity and chemical composition of topofrail products on adhesion. Tribology of the wheelrail contact aspects of wear, particle. The first part, mostly nonmathematical, contains a historical survey from the times of carter and fromm 1926 to the present day, in which all aspects. Reese has always strived to provide the right trailer towing system for each application. When traversing a curve, the angle of attack changes where leading wheel of. Output of various wheelrail contact parameters such as creep forces, contact angles and wheel rolling radii allow a detailed study of the wheelrail interaction. As the wheel rail contact is an open system, the adhesion between the wheel and rail is inevitably affected by contaminants. This radius can be different for the right and the left wheel as a wheelset is moving along a track r 1 andr 2 respectively, as shown in figure 2. This includes many improvements to the new wheelrail contact module, and has many options added to the free version.
At the point or points where the wheel touches the rail a contact patch develops. A new wheelrail contact model for railway dynamics article pdf available in vehicle system dynamics 452. Low adhesion in the wheelrail contact tu delft repositories. Determination of wheelrail contact points in the simulation of railway vehicle dynamics j.
Examination of the contact between the wheel and rail in curving action, as shown in figure 6, shows that the wheel tread makes contact at the top of the high rail while the wheel flange applies curving and steering lateral forces at the gauge face. The linearization of wheelrail contact described by mauer 18 can be simplified for small contact angles see fig. The size and shape of this contact patch can be calculated from the normal force, the local geometry of the wheel and the rail and the material properties. The linear conical wheel profile widely used before has burst linear. Appendix a effect of wheelrail profiles and wheelrail. Wheels are cast or forged and are heattreated to have a specific hardness. To do this for new profiles, drawings may be available but, after running for a little while, profiles will deviate significantly from the design case and it is essential to have accurate geometrical information of the worn profiles. Wheelrail contact properties an important characteristic of the contact between wheel and rail is the rolling radius of a wheel at the contact point 2, 3. The second widely used approach for friction modification at the wheelrail interface is a method of flange lubrication. The extensions of contact for wheel rail contact analysis are provided on a commercial basis, using a licensing mechanism. Contaminants, which refer to foreign substances applied both intentionally and unintentionally the wheel to rail interface, can make wheel rail adhesion either too high or too low and to difficult predict. A single contact patch between the wheel and the rail is typically the size of a small coin. A new approach to study the wheel rail contact problem in railway dynamics joao pombo, jorge ambrosio idmecinstituto superior tecnico, lisbon, portugal. Gemco rail is able to provide a complete range of services for freight, locomotive, and passenger wheels and axles.
Hence, the wheelrail rolling contact has been a hot issue. Less likely, the inner wheel tries to make the outer wheel turn slower, success resulting in negative scuff on the high rail. Methods to calculate accurate wheelrail contact positions and static. Understanding the effects of track gauge, wheelrail. A new approach to study the wheelrail contact problem in railway dynamics joao pombo, jorge ambrosio idmecinstituto superior tecnico, lisbon, portugal. This method becomes important for the vehicle running through. The first part, mostly nonmathematical, contains a historical survey from the times of carter and fromm 1926 to the present day, in which all aspects of rolling contact theory are discussed. Wheelrail interface handbook is a onestop reference for railway engineering practitioners and academic researchers. A new approach to study the wheelrail contact problem in. This entry describes the tribological system of the wheel and rail contact area of railway vehicles. Pdf a new wheelrail contact model for railway dynamics. Compared with the roller rig for test on a complete vehicle, the high controllability and flexibility of the single wheelset roller rig make it possible to obtain adequate data on the dynamics of the system and on wheelrail contact under various conditions which are essential for investigating the adhesion and creep of the wheel over the rail.
This is a minor update that provides improvements in the wheelrail contact module and the contact library. Understanding the wheelrail interface part one the. A rolling component is typically pressed onto an axle and mounted directly on a rail car or locomotive or indirectly on a bogie uk, also called a truck north america. A train wheel or rail wheel is a type of wheel specially designed for use on rail tracks. Analysis of wheelroller contact and comparison with the. The key requirement to calculate the fatigue and wear levels of wheels and rails is to establish a method that can accurately represent the. Presented at the 6th international conference on contact mechanics and wear of rail wheel systems cm2003 in gothenburg, sweden june 10, 2003 submitted to wear journal june 2003 optimal design of wheel profile for railway vehicles i. An approximate analysis for hertzian elliptical wheelrail. Full scale applications with standard wheelrail profiles will be modeled in the near future. The area of surface contact varies when the locomotive or car is in motion depending on steady state forces and other external forces when in motion. Contaminants, which refer to foreign substances applied both intentionally and unintentionally the wheel to rail interface, can make wheelrail adhesion either too high or too low and to difficult predict.
Applications are in the areas of vehicle design, safety performance evaluation, rail vehicle and track research, derailment investigation, and general simulation of. Appendix a effect of wheelrail profiles and wheelrail interaction on system performance and maintenance in transit operations unfortunately, this book cant be printed from the openbook. The wheel rail contact is no exception, where an understanding of interface pressures is essential, as this information is required in both fatigue and wear calculations for the. Friction in wheel rail contacts universiteit twente. Wheel and tire packages we sell tires and wheels, auto wheels, aftermarket wheels, car wheels, car rims, big wheels, new wheels, cheap tires,wheels online at discounted prices. This paper aims to investigate the influence of the asmanufactured steel microstructure and hardness along with the influence of wheel rail contact conditions on the observed damage such as rolling contact fatigue rcf cracks and plastic flow on the tread of railway wheels. New developments in the theory of wheelrail contact. Proceedings of the institution of mechanical engineers, part f. This paper aims to investigate the influence of the asmanufactured steel microstructure and hardness along with the influence of wheelrail contact conditions on the observed damage such as rolling contact fatigue rcf cracks and plastic flow on the tread of railway wheels. The premium version of contact automates the processing of wheel and rail profiles.
The dynamic wheelrail contact stresses for wagon on. The rail steel can be assumed to have a shear yield strength of k70 ksi. The main attention was paid to low adhesion issues, associated with the application of these products, because low adhesion can. This is why we offer as many as ten different trailer hitches for a single vehicle. Wheel plate and tread profiles of any shape can be produced for all freight, locomotive and passenger operations. A survey of wheelrail contact models for rail vehicles. Interface journal the journal of wheelrail interaction. 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 wheel rail contact problem jay prakash srivastava department of mechanical engineering. Part one provides the fundamentals of contact mechanics, wear, fatigue and lubrication as well as stateoftheart research and emerging technologies related to. Traktionsstromrichter doppelschichtkondensatoren traktionsbatterie. These irregularities generate fluctuations of the wheel rail contact force, which are responsible for the generation and transmission of vibrations to the environment as well as for fatigue damage and wear of the rolling stock.
Stecco, university of florence, italy abstract the numerical simulation of system dynamics is today a standard in the design. Materials used for wheels on rolling stock katrin madler, manfred bannasch deutsche bahn ag, technical centre, brandenburgkirchmoser, germany 1 introduction in the contact area between the wheel and the rail, the materials are used in those components encounter the greatest demands. This paper describes the theory of frictional rolling contact as far as it is significant for the wheel rail system. 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. Pdf wheelrail contact models for vehicle system dynamics. The other typical contact area between rail and wheel, that is, the wheel tread area and the rail surface or top of rail, is not subject of this entry, but is covered in a separate one, which specifically deals with reduction of noise and wheel squealing in railway operations. Specify section and weight of rail and width of crossing. The computational robustness of the wheelrail contact model is critical in vehicle system dynamics simulations. The paper presents an analysis of the effects of creepages on wheel rail contact forces. New wheels are trued, using a lathe, to a specific profile.
Passenger comfort evaluations and lading damage studies can be performed with nucars by simulation of vehicles running over measured track data. For numeric simulation, the transient wheelrail rolling contact in railway system is a very complex and timeconsuming process. Huge selection of quality brands in chrome wheels rims, wheel rim and tire packages for your car. A tool to estimate the wheelrail contact and temperature rising under dry, wet and oily conditions abstract in this paper, finite element method fem has been applied to evaluate the wheelrail contact stress under different contact conditions. The established model of the wheelrail contact dynamics has been applied to that same roll plane but. Adhesion traction is the friction between the drive wheels and the steel rail. The solid model of rail wheel contact model is created in catia v5. Wheel rail contact calculator file exchange matlab central. Measuring wheelrail contact stresses using ultrasound. Accurate and efficient contact models for wheel rail interaction are essential for the study of the dynamic behaviour of a railway vehicle.
Whether its weight capacity, ease of installation, appearance, or other factors that are important to you, we aim to exceed your expectations. This is a minor update that provides improvements in the wheel rail contact module and the contact library. The influence of wheelrail contact conditions on the. An adhesion railway relies on adhesion traction to move the train. Management on energy savings and sustainability railroad wheels and rails are made of high strength steel.
A new solution method for wheelrail rolling contact. Whether you are refurbishing, manufacturing, or maintaining rollingstock, our experienced and qualified staff and stateoftheart workshop facilities, can produce wheelset, bogies and bearing to oem specifications. Concerning the rail coordinate system, xb is parallel to the track direction, yb is on the plane defined by the rails and normal toxb, zb wi tr a nscti o engineering sciences, vol 62, 2009 wit press. The hybrid energy storage system can be integrated in. The standalone contact program for wheel rail contact. Comsteel utilises experienced personnel and sophisticated in house laboratories to develop material solutions to enhance wheel performance in specific applications. Wheel and straight track which is such that the unit vectors t. Increasing the availability of rail vehicles by increasing the line voltage y sitras hes enables operation without overhead contact line y energyefficient drive system for diesel multiple units and diesel shunting locomotives. Aug 24, 2015 to compensate, the outer wheel endeavours to make the inner wheel revolve more rapidly than the ideal and if successful, the consequence is positive scuff on the low rail.
Creepages are related to the motion of wheelset and wheel rail contact parameters. Friction management and control of adhesion at the wheelrail interface is vital for an efficient and cost effective railway network. The extensions of contact for wheelrail contact analysis are provided on a commercial basis, using a licensing mechanism. Wheelrail contact properties an important characteristic of the contact between wheel and rail is the rolling radius of a wheel at the contact point 3. At wheelrail contact, hertz equation can only be applied at the contact between wheel and rail head 2, however, not at the contact between wheel flange and gage corner since the radius of the contact body is smaller than the radius of contact area 5. 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. As the wheel and the rail are both bodies of revolution it is possible to describe this geometry by using the radii of curvature in. Bogie bas 2000 for that reason, the classical approach is unsuitable because in the present case, each wheel of the vehicle should be considered separately. Reasonable solution method would reduce the computational effort and improve the solution efficiency in a certain extent. Numerical models of railway tracks for obtaining frequency. The rolling radius difference is dependent on the contact angle between wheel and rail and on the local curvatures of wheel and rail profiles. Any quantity from a single item to delivery quantities of many thousands are possible from our facility. This radius can be different for the right and the left wheel as a wheelset is moving along a track r1 andr2 respectively, as shown in.
By bob tuzik for three years running, new york city transit and the federal transit administration have kicked off the annual wheelrail interaction rail transit conference with discussion of the nyctfta research project to explore integrated wheelrail analytics on mtanycts no. This paper describes the theory of frictional rolling contact as far as it is significant for the wheelrail system. A tool to estimate the wheelrail contact and temperature. A steel wheel requires very little energy to roll on a steel rail. A generic wheelrail contact detection formulation is presented here in order to determine online the contact points. This is because the wheel and rail deform very little under load, unlike a rubber. If you need to print pages from this book, we recommend downloading it as a pdf. The program includes detailed nonlinear models of wheelrail interaction and suspension response, with wheelrail interaction based on kalkers complete nonlinear creep theory. Work on rails, at crossings and at the side of tracks. Control trackside vegetation, build and repair railroad crossings, clean up landslides or replace rails and ties with the industrys most versatile and mobile maintenance machines. 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, with a typical radius of 7mm. Also parameters phi1 and phi2 for johnson and kalker methods were set.
The wheel rail contact inevitably operates in a contaminated environment. The new dlr railwaydynamics library, to which this. A new wheelrail contact model for railway dynamics. The dynamic wheelrail contact stresses for wagon on various. This section therefore presents an appropriate model for a single wheelrail contact which.
The position of the mass center and of the wheel contact point are given by the. Jan 12, 2016 compared with the roller rig for test on a complete vehicle, the high controllability and flexibility of the single wheelset roller rig make it possible to obtain adequate data on the dynamics of the system and on wheelrail contact under various conditions which are essential for investigating the adhesion and creep of the wheel over the rail. Determination of wheelrail contact points in the simulation. The starting point for an analysis of wheelrail contact is the identification of the size and shape of the contact patch. Pdf advanced modelling of rail vehicle dynamics requires realistic solutions of.
The results show that the maximal normal wheel rail contact stresses is under 1600mpa in a range of conditions typical of normal operation. The material used for the railwheel contact is structural steel which isotropic behavior. Guide wheel rail gear system allows excavator to be propelled by the drive system of the machine dmf 1650 50,000 lbs. Wheel rail contact properties an important characteristic of the contact between wheel and rail is the rolling radius of a wheel at the contact point 2, 3.
The internal side rail in this contact is worn intensively 24. The main cause of the vibrations generated by railway traffic is the irregularities of the wheel and rail profiles. Clearly, the pressures at the key interface are very high, considerably in excess of the normal yield stress. Aic rail has partnered with highquality, likeminded companies in an effort to provide complete solutions for our rail customers. Outofround railway wheels wheelrail contact forces and track response derived from field tests and numerical simulations.
Rail sections tee rail data diagram dimensions for tee rail data table ht height bw width of base hw width of head. You will still receive priority support for these products through aic. Determination of geometric contact characteristics for given wheel and rail profiles, wheel and rail gauge, and railhead cant angles is a wellknown and solved problem for many years. The standalone contact program for wheelrail contact. Review of joost kalkers wheelrail contact theories and their. Measuring wheelrail contact stresses using ultrasound m. The investigation of contact area and pressure distribution in.
Assessment of the contact forces and moments, as well. Introduction the assessment of structural integrity is a key part of mechanical engineering design. Purchase mechanics and fatigue in wheelrail contact 1st edition. It is furnished complete with steel face plate, shim, track bolts, nuts and. The term adhesion railway is only used when there is need to distinguish adhesion railways from railways moved by other means, e. As the wheelrail contact is an open system, the adhesion between the wheel and rail is inevitably affected by contaminants. Due to the unique nature of the comsteel rail wheel manufacturing facility, we offer complete flexibility in product supply quantities. In the context of this entry, special attention is paid to the contact area of the wheel flange with the corresponding rail flank and the methods used to lubricate this system effectively in order to reduce wear and tear of wheels and rails, to increase running safety, and to reduce energy. The contact model between wheel and rail is approximated to be elliptical, which is shown to be accurate for the described purpose. A complete australia wagon with threepiece bogies was modelled and various tracks were selected for the simulation of dynamic wheel rail contact stresses. Some materials are deliberately applied to the rail to increase traction, reduce wear, or postpone the onset of fatigue. Parameters n and m for contact pressure were set in 10 and 8, respectively. Materials used for wheels on rolling stock railway research.
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