Study of the Falling Friction Effect on Rolling Contact Parameters

[EN] The existence of a wheel rail friction coefficient that depends on the slip velocity has been associated in the literature with important railway problems like the curving squeal and certain corrugation problems in rails. Rolling contact models that take into account this effect were carried out through the so-called Exact Theories adopting an exact elastic model of the solids in contact, and Simplified Theories which assume simplified elastic models such as Winkler. The former ones, based on Kalker s Variational Theory, give rise to numerical problems; the latter ones need to adopt hypotheses that significantly deviate from actual conditions, leading to unrealistic solutions of the contact problem. In this paper, a methodology based on Kalker s Variational Theory is presented, in which a local slip velocity-dependent friction law is considered. A formulation to get steady-state conditions of rolling contact by means of regularisation of the Coulomb s law is proposed. The model allows establishing relationships in order to estimate the global properties (creepage velocities vs. total longitudinal forces) through local properties (local slip velocity vs. coefficient of friction) or vice versa. The proposed model shows a good agreement with experimental tests while solving the numerical problems previously mentioned.The authors acknowledge the financial contribution of the Spanish Ministry of Economy and Competitiveness through the Project TRA2013-45596-C2-1-R.Giner Navarro, J.; Baeza González, LM.; Vila Tortosa, MP.; Alonso Pazos, A. (2017). Study of the Falling Friction Effect on Rolling Contact Parameters. Tribology Letters. 65(1). https://doi.org/10.1007/s11249-016-0810-8S651Grassie, S.L., Elkins, J.A.: Rail corrugation on North American transit systems. Veh. Syst. Dyn. 28, 5–17 (1998)Hsu, S.S., Huang, Z., Iwnicki, S.D., Thompson, D.J., Jones, C.J.C., Xie, G., Allen, P.D.: Experimental and theoretical investigation of railway wheel squeal. Proc. Inst. Mech. Eng. F J. Rail Rapid Transit 221, 59–73 (2007)Kalker, J.J.: Three-Dimensional Elastic Bodies in Rolling Contact. Kluwer, Dordrecht (1990)Polach, O.: Influence of locomotive tractive effort on the forces between wheel and rail. Veh. Syst. Dyn. 35, 7–22 (2001)Giménez, J.G., Alonso, A., Gómez, E.: Introduction of a friction coefficient dependent on the slip in the FastSim algorithm. Veh. Syst. Dyn. 43, 233–244 (2005)Baeza, L., Vila, P., Roda, A., Fayos, J.: Prediction of corrugation in rails using a non-stationary wheel–rail contact model. Wear 265, 1156–1162 (2008)Vollebregt, E.A.H., Schuttelaars, H.M.: Quasi-static analysis of two-dimensional rolling contact with slip-velocity dependent friction. J. Sound Vib. 331, 2141–2155 (2012)Avlonitis, M., Kalaitzidou, K., Streator, J.: Investigation of friction statics and real contact area by means a modified OFC model. Tribol. Int. 69, 168–175 (2014)Berger, E.J., Mackin, T.J.: On the walking stick–slip problem. Tribol. Int. 75, 51–60 (2014)Alonso, A., Guiral, A., Baeza, B., Iwnicki, S.D.: Wheel–rail contact: experimental study of the creep forces–creepage relationships. Veh. Syst. Dyn. 52(S1), 469–487 (2014)Spiryagin, M., Polach, O., Cole, C.: Creep force modelling for rail traction vehicles based on the Fastsim algorithm. Veh. Syst. Dyn. 51, 1765–1783 (2013)Vollebregt, E.A.H.: Numerical modeling of measured railway creep versus creep-force curves with CONTACT. Wear 314, 87–95 (2014)Kalker, J.J.: On the Rolling Contact of Two Elastic Bodies in the Presence of Dry Friction. PhD Thesis, Technical University of Delft (Holland) (1967)Baeza, L., Fuenmayor, F.J., Carballeira, J., Roda, A.: Influence of the wheel–rail contact instationary process on contact parameters. J. Strain Anal. Eng. 42, 377–387 (2007)Le Rouzic, J., Le Bot, A., Perret-Liaudet, J., Guibert, M., Rusanov, A., Douminge, L., Bretagnol, F., Mazuyer, D.: Friction-induced vibration by Stribeck’s law: application to wiper blade squeal noise. Tribol. Lett. 49, 563–572 (2013)Rabinowicz, E.: The nature of the static and kinetic coefficients of friction. J. Appl. Phys. 22, 1373–1379 (1951)Carter, F.W.: On the action of locomotive driving wheel. Proc. R. Soc. Lon. Ser. A 112, 151–157 (1926)Kalker, J.J.: A fast algorithm for the simplified theory of rolling contact. Veh. Syst. Dyn. 11, 1–13 (1982

Heavy haul locomotive traction performance under the implications of in-train forces

Cole, CR ORCiD: 0000-0001-8840-7136; Spiryagin, M ORCiD: 0000-0003-1197-898X; Wu, Q ORCiD: 0000-0001-9407-5617This paper conducted co-simulations to examine locomotive traction performance in a heavy haul train operational environment. A Longitudinal Train Dynamics (LTD) simulation package was connected with a multibody vehicle system dynamics simulation package called GENSYS using the TCP/IP protocol. The LTD simulations replicated the dynamic environment (in-train forces) of train operations while the vehicle system dynamics simulations integrated wheel/rail contact models and mechatronic traction control models for locomotives. In-train forces and a traction reference were sent to GENSYS to determine traction efforts which were then sent back to LTD. A distributed-power train with the configuration of 1 locomotive + 61 wagons + 1 locomotive + 61 wagons was modelled. A conventional LTD simulation and a co-simulation were conducted. The results show that, due to adhesion limits, both LTD and co-simulation did not achieve the maximum traction force specified by locomotive characteristics curves. The maximum traction force achieved in co-simulation was 170 kN lower than that in LTD simulation. The average speed simulated by co-simulation was about 10% slower than that by LTD

Simulation of track-locomotive interactions in the longitudinal direction

Cole, CR ORCiD: 0000-0001-8840-7136; Spiryagin, M ORCiD: 0000-0003-1197-898X; Wu, Q ORCiD: 0000-0001-9407-5617Interest has been expressed from industry regarding the investigation of longitudinal interactions of tracks and locomotives. The majority of railway track dynamics models focus on vertical and lateral directions; railway track longitudinal force models are rarely published. This paper developed a three dimensional railway track model which considers four structure layers: rails, sleepers, ballast and subballast. The rails are modelled using the Finite Element Method (FEM) and each node has six Degrees of Freedom (DoFs). Sleepers are modelled as rigid bodies and each also has six DoFs. Ballast and subballast are modelled as blocks and each has three translational DoFs. Frictional behaviour is considered in the longitudinal direction of the fastening models as well as in the longitudinal and lateral directions of the sleeper-ballast force connections. Locomotive-track interaction simulations are conducted using a parallel cosimulation technique to combine the track model to a locomotive model developed in GENSYS

Anti-slip control system of a locomotive

This article describes the anti-slip control system of a railway vehicle. The proposed system has two control stages. This system works based on adhesive force as a main criterion, which provides a robust working locomotive with effective adhesion between wheels and rails

Design and simulation of heavy haul locomotives and trains

Cole, CR ORCiD: 0000-0001-8840-7136; Mcsweeney, TC ORCiD: 0000-0003-3098-2423; Spiryagin, M ORCiD: 0000-0003-1197-898X; Wolfs, PJ ORCiD: 0000-0001-7048-1231If locomotive brakes are controlled appropriately, ECP braking systems can be tuned so that there are no intrain forces or interwagon impacts ... Heavy haul trains continue to push the limits of train design in both yield strength and fatigue life

Preface

This special issue presents the ‘State-of-Art’ papers included in the program of the 25th International Symposium on Dynamics of Vehicles on Roads and Tracks. The biennial IAVSD Symposia have been held in internationally renowned locations and this historic event took place in Australia for the first time, being held at Central Queensland University in Rockhampton, Queensland from 14 to 18 August 2017. The organiser of this Symposium was the Centre for Railway Engineering, an industry-focused research organisation well known for its research expertise in train, locomotive, wagon and bogie dynamics, rail vehicle/track system dynamics, simulation, instrumentation and field testing. The International Symposium on Dynamics of Vehicles on Roads and Tracks is the leading international symposium bringing together researchers, scientists and engineers from academia and industry to present and exchange their latest ideas and breakthroughs. The papers contained in this special issue were selected by the Board of Trustees of the International Association for Vehicle System Dynamics and these papers present the latest developments achieved by the leading academic and industry experts in the field of road and rail vehicle dynamics and associated research areas

Rail passenger vehicle crashworthiness simulations using multibody dynamics approaches

Multibody dynamics approaches have nowadays been an essential part in examining train crashworthiness. A typical passenger train structure has been investigated on its crashworthiness using three-dimensional (3D) models of a single passenger car and multiple cars formulated using multibody dynamics approaches. The simulation results indicate that the crush length or crush force or both of the crush mechanisms in the high and low energy (HE and LE) crush zones of a passenger train have to be increased for the higher crash speeds. The results on multiple cars (up to ten cars) show that the design of HE and LE crush zones is significantly influenced by the number of cars. The energy absorbed by the HE zone is reasonably consistent for train models with more than four cars at the crash speed of 35 km/h. The comparison of simulations can identify the contribution of the number of cars to the head-on crash forces. The influence of train mass on the design of both HE and LE crush zones, and the influence of design of the crush zones on the wheel-rail contacts are examined. © 2017 by ASME

Modelling of traction in railway vehicles

The design concept of locomotives, which was introduced more than 200 years ago, continues to be developed and further improved. The progress of science and technology, especially in the field of computer modelling, allows rapid adoption of new and advanced forms of traction to railway vehicles. Recent publications [1,2] show that the design process requires the application of modern and advanced simulation techniques and tools. When undertaking theoretical and experimental studies on the behaviour of rail traction vehicles, it is necessary to solve multidisciplinary problems in vehicle system dynamics [3] and it is also highly desirable to evaluate the whole vehicle as a mechatronic system.[2,4] The process therefore requires the application of specialised software tools to evaluate vehicle behaviour, the development of a mechatronic system model (control system and vehicle dynamics model) and its verification