Mechanics and Novel Designs of Polymeric Railway Sleepers in Track Structure

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68407700%3A21110%2F24%3A00376613" target="_blank" >RIV/68407700:21110/24:00376613 - isvavai.cz</a>

Výsledek na webu

<a href="https://doi.org/10.4203/ccc.7.20.6" target="_blank" >https://doi.org/10.4203/ccc.7.20.6</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.4203/ccc.7.20.6" target="_blank" >10.4203/ccc.7.20.6</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Mechanics and Novel Designs of Polymeric Railway Sleepers in Track Structure

Popis výsledku v původním jazyce

Polymer sleepers can combine a stiffness behaviour comparable to timber sleepers with the consistency and lifespan of concrete sleepers, but their specific characteristics and potential advantages should be considered: material viscoelasticity, bending stiffness range, and freedom of shape. Due to viscoelasticity, laboratory tests on polymer sleepers should be performed dynamically, at strain rates applicable to in-track conditions. Cyclic loading should be performed intermittently, introducing pauses between cycling to reduce heating, creep effects and to give track representative results. In analyses, polymer (and timber) sleepers should be considered a beam on an elastic foundation, because of their limited bending stiffness. To accommodate analytical calculations, a simplified calculation method was derived, using a sleeper flexibility factor to account for sleeper bending effects on track deflections. As a result of repeated train loads, a gap arises between the rail seat location and ballast, and the sleeper shapes according to this gap (i.e. beds-in) on every train passage, causing equalization of the contact stresses over the sleeper length and ballast. Optimisation show that balancing the sleeper (prevention of centre-bound) can reduce resilient rail seat displacements by up to 40% without increasing material usage but only utilizing moulding processes allowing the freedom of sleeper shape.

Název v anglickém jazyce

Mechanics and Novel Designs of Polymeric Railway Sleepers in Track Structure

Popis výsledku anglicky

Polymer sleepers can combine a stiffness behaviour comparable to timber sleepers with the consistency and lifespan of concrete sleepers, but their specific characteristics and potential advantages should be considered: material viscoelasticity, bending stiffness range, and freedom of shape. Due to viscoelasticity, laboratory tests on polymer sleepers should be performed dynamically, at strain rates applicable to in-track conditions. Cyclic loading should be performed intermittently, introducing pauses between cycling to reduce heating, creep effects and to give track representative results. In analyses, polymer (and timber) sleepers should be considered a beam on an elastic foundation, because of their limited bending stiffness. To accommodate analytical calculations, a simplified calculation method was derived, using a sleeper flexibility factor to account for sleeper bending effects on track deflections. As a result of repeated train loads, a gap arises between the rail seat location and ballast, and the sleeper shapes according to this gap (i.e. beds-in) on every train passage, causing equalization of the contact stresses over the sleeper length and ballast. Optimisation show that balancing the sleeper (prevention of centre-bound) can reduce resilient rail seat displacements by up to 40% without increasing material usage but only utilizing moulding processes allowing the freedom of sleeper shape.

Druh

D - Stať ve sborníku

CEP obor

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OECD FORD obor

20102 - Construction engineering, Municipal and structural engineering

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2024

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název statě ve sborníku

Proceedings of the Sixth International Conference on Railway Technology: Research, Development and Maintenance

ISBN

—

ISSN

2753-3239

e-ISSN

2753-3239

Počet stran výsledku

15

Strana od-do

—

Název nakladatele

Civil-Comp Press

Místo vydání

Edinburgh

Místo konání akce

Praha

Datum konání akce

1. 9. 2024

Typ akce podle státní příslušnosti

WRD - Celosvětová akce

Kód UT WoS článku

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