Testing and Analysis Techniques for Safety Assessment of Rail Vehicles: The State-of-the-Art

Elkins, J A; Carter, A.

doi:10.1080/00423119308969026

Cited by 42 publications

(37 citation statements)

References 2 publications

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“…Nadal's formulation is widely studied in the bibliography, as for example in references [6,17]. The importance of the Nadal criterion lies in that it furnishes a limit value for the lateral force which may be applied to the wheel, below which there is a guarantee that the flange cannot climb up the head of the rail, and therefore derailment will not take place.…”

Section: Nadal's Equationmentioning

confidence: 99%

“…Since these expressions are deduced in a system of coordinates linked to the track, they are independent of the track cant angle and can be used when the vehicle is negotiating a curve. The friction coefficient, which does not appear explicitly in the equations, is introduced by assuming saturation of the tangential force in the contact according to expression (6). If the tangential force is saturated, the components T x and T y are not independent.…”

Section: Analysis Of Creepage Forces In 3-dmentioning

confidence: 99%

“…In recent years a number of researchers have come up with alternative formulations or formulations as complements to Nadal's limit in order to establish derailment risk indicators more in touch with reality [6]. Experimentation has proved, for instance, that for derailment to take place it is necessary that the lateral force applied to the wheel be maintained for a certain period of time, and certain theories add to Nadal's limit by establishing minimum periods of time during which the lateral force must be maintained for derailment to take place [11].…”

Section: Alternative Formulationsmentioning

confidence: 99%

“…There is a general perception, observed by a large number of experimental measurements, that Nadal's formula is rather conservative [3][4][5][6][7][8]. Tests have been performed in which derailment occurred for a forces quotient much greater than the limit envisaged in the equation [3,9].…”

Section: Introductionmentioning

confidence: 99%

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Influence of creep forces on the risk of derailment of railway vehicles

Santamaría

Vadillo

Gómez

2009

Vehicle System Dynamics

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Abstract:The derailment mechanism in a railway vehicle is a complex mechanical phenomenon which has been, and still is, the subject of intense research activity due to the serious consequences it can entail. Since Nadal deduced his well-known formula, many researchers have put forward alternative equations which all attempt to move closer to data obtained experimentally. This paper provides a summary of the best known, and draws up a new formulation based on the theoretical 3-D study of creep forces emerging in contact on the wheel likely to derail. It also provides an in-depth analysis of the role played by spin creepage, including its effect on obtaining theoretical derailment limits which are more realistic than those obtained using Nadal's formula. Finally, a new derailment criteria is proposed. This new criteria leads to less conservative values than Nadal's equation for zero yaw angles. When the yaw angle is high enough, the results obtained are coincident with those predicted by Nadal's equation.

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Section: Nadal's Equationmentioning

confidence: 99%

Section: Analysis Of Creepage Forces In 3-dmentioning

confidence: 99%

Section: Alternative Formulationsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Influence of creep forces on the risk of derailment of railway vehicles

Santamaría

Vadillo

Gómez

2009

Vehicle System Dynamics

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“…When using dynamic tests to measure the dynamic indices of a track inspection vehicle and a new designed vehicle, we need instrumented wheelset and some accelerometers installed on the tested vehicles. However, the instrumented wheelset is known as an expensive device and involves a complicated calibration technology [1][2][3][4][5][6][7]. In addition, some structural modifications to the wheelset, e.g., drilling holes on the wheel hub, are necessary for the signal transmission and power supply, which means that this device is not suitable for long-term commercial operation of the train.…”

Section: Introductionmentioning

confidence: 99%

Safety evaluation for railway vehicles using an improved indirect measurement method of wheel–rail forces

Zeng

Lai

2016

J. Mod. Transport.

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The wheel-rail force measurement is of great importance to the condition monitoring and safety evaluation of railway vehicles. In this paper, an improved indirect method for wheel-rail force measurement is proposed to evaluate the running safety of railway vehicles. In this method, the equilibrium equations of a suspended wheelset are derived and the wheel-rail forces are then be obtained from measured suspension and inertia forces. This indirect method avoids structural modifications to the wheelset and is applicable to the long-term operation of railway vehicles. As the wheel-rail lateral forces at two sides of the wheelset are difficult to separate, a new derailment criterion by combined use of wheelset derailment coefficient and wheel unloading ratio is proposed. To illustrate its effectiveness, the indirect method is applied to safety evaluation of railway vehicles in different scenarios, such as the cross wind safety of a high-speed train and the safety of a metro vehicle with hunting motions. Then, the feasibility of using this method to identify wheel-rail forces for low-floor light rail vehicles with resilient wheels is discussed. The values identified by this method is compared with that by Simpack simulation for the same low-floor vehicle, which shows a good coincidence between them in the time domain of the wheelset lateral force and the wheel-rail vertical force. In addition, use of the method to determine the high-frequency wheel-rail interaction forces reveals that it is possible to identify the high-frequency wheel-rail forces through the accelerations on the axle box.

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Bibliography

2021

Mathematical Foundation of Railroad Vehicle Systems

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Bibliography1. ACC. (2017). Competitive switching: making the switch to a more competitive, healthy freight rail system. Freight Rail Reform. https://www.freightrailreform.com/ making-the-switch-to-a-more-competitive-healthy-freight-rail-system. 2. Andersson, C. and Abrahamsson, T. (2002). Simulation of interaction between a train in general motion and a track. Vehicle System Dynamics 38: 433-455.

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Testing and Analysis Techniques for Safety Assessment of Rail Vehicles: The State-of-the-Art

Cited by 42 publications

References 2 publications

Influence of creep forces on the risk of derailment of railway vehicles

Influence of creep forces on the risk of derailment of railway vehicles

Safety evaluation for railway vehicles using an improved indirect measurement method of wheel–rail forces

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