Wheel forces during flange climb. I. Track loading vehicle tests

Shust, William; Elkins, J A

doi:10.1109/rrcon.1997.581394

Cited by 10 publications

(13 citation statements)

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“…On the other hand, the risk of wheel climb derailment will be increased if the traction coefficient is too high at sharp curves because it generates a greater force in the lateral direction, namely toward to the outside of a curve. The force presses the wheelset against the gauge corner of the outer rail and could cause the flange to climb up [1][2] [3]. Therefore, it is important to understand the phenomenon and appropriately control the friction condition.…”

Section: Introductionmentioning

confidence: 99%

Tribological aspects to optimize traction coefficient during running-in period using surface texture

Fukagai

Lewis

2019

Wear

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Risk of wheel-climb derailment increases if the traction coefficient in the wheel/rail contact is too high. This has been observed to happen more just after wheel turning. This novel work investigates how the traction coefficient rises during the running-in period, when textured surfaces are used to simulate a freshly turned wheel. Running-in curve of traction coefficient showed a momentary rise and a peak value of traction coefficient was observed to decrease with the increase in magnitude of the wheel surface texture. The change of the subsurface hardness and the microstructure were also dependent on the initial surface texture coincidentally and the work-hardening layer of the textured surface was thicker than that of smooth surface. A mechanism model of the effects of surface texture on traction characteristics during the running-in was presented. The work will allow recommendations of wheel turning to be made to help reduce the problem of wheel-climb derailment.

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Section: Introductionmentioning

confidence: 99%

Tribological aspects to optimize traction coefficient during running-in period using surface texture

Fukagai

Lewis

2019

Wear

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“…On the other hand, it is known that high traction coefficient and slip at curves could lead to severe wear and deformation of wheel and rail, energy consumption and squealing noise [1]. It also increases the risk of a wheel climb derailment occurring [2][3] [4]. Nakahara et al reported that the traction condition between a wheel and rail changes with a train traffic passage even in the dry condition [5] and showed some transient traction curves using twin-disk testing which indicated that traction coefficient varies with the evolution of surface roughness during running-in [6].…”

Section: Introductionmentioning

confidence: 99%

Transitions in rolling-sliding wheel/rail contact condition during running-in

Fukagai

Brunskill

Hunter

et al. 2020

Tribology International

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The risk of wheel-climb derailment increases if the traction coefficient in the wheel/rail contact is too high. This has been observed to happen more frequently just after wheel machining. This work investigates how the traction coefficient rises with evolution of the wheel/rail interface during the running-in. Experiments were performed using a fullscale wheel/rail contact rig and an ultrasonic array transducer mounted in the rail. Results were used to determine the stiffness of the contact interface. Contact stiffness appeared to be positively correlated with the traction coefficient. Owing to the conforming of the interface, contact stiffness increases before the traction coefficient rises. The work will allow recommendation of wheel machining to be made to help reduce the problem of wheel-climb derailment.

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“…Therefore, he pointed out that the sum of the derailment coefficients at both sides of the wheelset could be adopted as a criterion in evaluating wheel derailment, and, to a certain extent, corrected the conservative Nadal derailment evaluation criterion under small attack angles. Elkins and Shust [7,8] investigated the influence of friction coefficient and wheel-rail attack angle on rail climbing of wheels. They argued that rail climbing of wheels depended on the vehicle running distance when derailment coefficient is out of safe region rather than the duration of the unsafe derailment coefficient.…”

Section: Introductionmentioning

confidence: 99%

Theoretical 3D Model for Quasistatic Critical Derailment Coefficient of Railway Vehicles and a Simplified Formula

Wang

et al. 2018

Mathematical Problems in Engineering

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The formula for the critical derailment coefficient concerning wheelset yaw angles and wheel-rail creep forces is deduced based on the three-dimensional (3D) force equilibrium relationship in the critical wheel derailment state under quasistatic assumption. The change of critical derailment coefficient and wheel-rail contact patch normal force/creep force as wheelset yaw angles change under the influence of the friction coefficient, maximum flange angle, and net wheel weight is analyzed according to the Kalker linear creep theory and Shen-Hedrick-Elkins creep theory. Analysis shows that the wheel-rail friction coefficient and maximum wheel flange contact angle can significantly influence the critical wheel derailment coefficient, further proving the conservative results when the critical Nadal derailment coefficient is adopted in analyzing wheel derailment under small wheelset yaw angles. To realize easy calculation and application of critical 3D derailment coefficients, the ratio of lateral creep force to longitudinal creep force of wheel-rail contact patches under critical quasistatic wheel derailment conditions is deduced. A simplified calculation method of critical derailment coefficients is presented based on this. The calculation accuracy is verified, proving that it can satisfy engineering application.

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Wheel forces during flange climb. I. Track loading vehicle tests

Cited by 10 publications

References 0 publications

Tribological aspects to optimize traction coefficient during running-in period using surface texture

Tribological aspects to optimize traction coefficient during running-in period using surface texture

Transitions in rolling-sliding wheel/rail contact condition during running-in

Theoretical 3D Model for Quasistatic Critical Derailment Coefficient of Railway Vehicles and a Simplified Formula

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