Use of shakedown maps to assess plastic flow in railway curves

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Abstract

Plastic deformation of rails can occur on tight curves, which can significantly reduce rail life. This paper investigated the phenomena of gross plastic deformation, or plastic flow, using multibody vehicle-track interaction and simplified finite element analysis. The focus is on understanding the contact conditions on the low rail of curves and how these differ from those in shakedown maps. To this end, two trial sites are simulated using multibody vehicle-track software. The contact conditions are then compared against several criteria assumed in the derivation of the shakedown maps. A further assumption implicit in the shakedown maps is also investigated by a non-linear finite element analysis. In this case, a more realistic Chaboche material model is used as opposed to the simple linear elastic perfectly plastic model in shakedown theory. The results of the finite element analysis are combined with a bespoke indicator of plastic flow to assess the influence of distance to shakedown limits on likely plastic flow. Finally, a simple interpolation scheme is used to map the finite element results back to the trial sites. The interpolated results for the sites are used to evaluate the influence of running speed and different levels of wheel profile wear. Results suggest that the bespoke indicator defined in this work can be used as an effective measure of plastic flow; this measure is then used to quantify the influence of cant excess on rates of plastic flow.
LanguageEnglish
JournalProceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit
Publication statusAccepted/In press - 31 Aug 2019

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Plastic flow
Rails
Finite element method
Plastic deformation
Interpolation
Wheels
Wear of materials
Plastics

Cite this

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title = "Use of shakedown maps to assess plastic flow in railway curves",
abstract = "Plastic deformation of rails can occur on tight curves, which can significantly reduce rail life. This paper investigated the phenomena of gross plastic deformation, or plastic flow, using multibody vehicle-track interaction and simplified finite element analysis. The focus is on understanding the contact conditions on the low rail of curves and how these differ from those in shakedown maps. To this end, two trial sites are simulated using multibody vehicle-track software. The contact conditions are then compared against several criteria assumed in the derivation of the shakedown maps. A further assumption implicit in the shakedown maps is also investigated by a non-linear finite element analysis. In this case, a more realistic Chaboche material model is used as opposed to the simple linear elastic perfectly plastic model in shakedown theory. The results of the finite element analysis are combined with a bespoke indicator of plastic flow to assess the influence of distance to shakedown limits on likely plastic flow. Finally, a simple interpolation scheme is used to map the finite element results back to the trial sites. The interpolated results for the sites are used to evaluate the influence of running speed and different levels of wheel profile wear. Results suggest that the bespoke indicator defined in this work can be used as an effective measure of plastic flow; this measure is then used to quantify the influence of cant excess on rates of plastic flow.",
author = "Samuel Hawksbee and Gareth Tucker and Mark Burstow",
year = "2019",
month = "8",
day = "31",
language = "English",
journal = "Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit",
issn = "0954-4097",
publisher = "SAGE Publications Ltd",

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TY - JOUR

T1 - Use of shakedown maps to assess plastic flow in railway curves

AU - Hawksbee, Samuel

AU - Tucker, Gareth

AU - Burstow, Mark

PY - 2019/8/31

Y1 - 2019/8/31

N2 - Plastic deformation of rails can occur on tight curves, which can significantly reduce rail life. This paper investigated the phenomena of gross plastic deformation, or plastic flow, using multibody vehicle-track interaction and simplified finite element analysis. The focus is on understanding the contact conditions on the low rail of curves and how these differ from those in shakedown maps. To this end, two trial sites are simulated using multibody vehicle-track software. The contact conditions are then compared against several criteria assumed in the derivation of the shakedown maps. A further assumption implicit in the shakedown maps is also investigated by a non-linear finite element analysis. In this case, a more realistic Chaboche material model is used as opposed to the simple linear elastic perfectly plastic model in shakedown theory. The results of the finite element analysis are combined with a bespoke indicator of plastic flow to assess the influence of distance to shakedown limits on likely plastic flow. Finally, a simple interpolation scheme is used to map the finite element results back to the trial sites. The interpolated results for the sites are used to evaluate the influence of running speed and different levels of wheel profile wear. Results suggest that the bespoke indicator defined in this work can be used as an effective measure of plastic flow; this measure is then used to quantify the influence of cant excess on rates of plastic flow.

AB - Plastic deformation of rails can occur on tight curves, which can significantly reduce rail life. This paper investigated the phenomena of gross plastic deformation, or plastic flow, using multibody vehicle-track interaction and simplified finite element analysis. The focus is on understanding the contact conditions on the low rail of curves and how these differ from those in shakedown maps. To this end, two trial sites are simulated using multibody vehicle-track software. The contact conditions are then compared against several criteria assumed in the derivation of the shakedown maps. A further assumption implicit in the shakedown maps is also investigated by a non-linear finite element analysis. In this case, a more realistic Chaboche material model is used as opposed to the simple linear elastic perfectly plastic model in shakedown theory. The results of the finite element analysis are combined with a bespoke indicator of plastic flow to assess the influence of distance to shakedown limits on likely plastic flow. Finally, a simple interpolation scheme is used to map the finite element results back to the trial sites. The interpolated results for the sites are used to evaluate the influence of running speed and different levels of wheel profile wear. Results suggest that the bespoke indicator defined in this work can be used as an effective measure of plastic flow; this measure is then used to quantify the influence of cant excess on rates of plastic flow.

M3 - Article

JO - Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit

T2 - Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit

JF - Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit

SN - 0954-4097

ER -