Estudio de los defectos tipo squat en los rieles del Metro de Medellín

Ilustraciones, fotografías, gráficas

Autores:: García Jiménez, Jose Alejandro

Tipo de recurso:

Fecha de publicación:: 2024

Institución:: Universidad Nacional de Colombia

Repositorio:: Universidad Nacional de Colombia

Idioma:: spa

id	UNACIONAL2_09d0766bf0a0f651757cc64ab61e373a
oai_identifier_str	oai:repositorio.unal.edu.co:unal/86845
network_acronym_str	UNACIONAL2
network_name_str	Universidad Nacional de Colombia
repository_id_str
dc.title.spa.fl_str_mv	Estudio de los defectos tipo squat en los rieles del Metro de Medellín
dc.title.translated.eng.fl_str_mv	Study of squat-type defects in the rails of the Medellín Metro
title	Estudio de los defectos tipo squat en los rieles del Metro de Medellín
spellingShingle	Estudio de los defectos tipo squat en los rieles del Metro de Medellín 620 - Ingeniería y operaciones afines::625 - Ingeniería de ferrocarriles y de carretera Ferrocarriles - Mantenimiento y reparación Transporte ferroviario - Medellín (Colombia) Vías férreas - Medellín (Colombia) Vías férreas - Mantenimiento y reparación Rieles (Ferrocarriles) - Mantenimiento y reparación Defectos tipo squat Desgaste ondulatorio Endurecimiento por deformación Squat-type defects Corrugation wear Strain hardening
title_short	Estudio de los defectos tipo squat en los rieles del Metro de Medellín
title_full	Estudio de los defectos tipo squat en los rieles del Metro de Medellín
title_fullStr	Estudio de los defectos tipo squat en los rieles del Metro de Medellín
title_full_unstemmed	Estudio de los defectos tipo squat en los rieles del Metro de Medellín
title_sort	Estudio de los defectos tipo squat en los rieles del Metro de Medellín
dc.creator.fl_str_mv	García Jiménez, Jose Alejandro
dc.contributor.advisor.none.fl_str_mv	Toro, Alejandro
dc.contributor.author.none.fl_str_mv	García Jiménez, Jose Alejandro
dc.contributor.researchgroup.spa.fl_str_mv	Grupo de Tribología y Superficies
dc.contributor.orcid.spa.fl_str_mv	García Jiménez, Jose Alejandro [0000-0002-2549-9982]
dc.contributor.cvlac.spa.fl_str_mv	Jose A. García-Jiménez
dc.subject.ddc.spa.fl_str_mv	620 - Ingeniería y operaciones afines::625 - Ingeniería de ferrocarriles y de carretera
topic	620 - Ingeniería y operaciones afines::625 - Ingeniería de ferrocarriles y de carretera Ferrocarriles - Mantenimiento y reparación Transporte ferroviario - Medellín (Colombia) Vías férreas - Medellín (Colombia) Vías férreas - Mantenimiento y reparación Rieles (Ferrocarriles) - Mantenimiento y reparación Defectos tipo squat Desgaste ondulatorio Endurecimiento por deformación Squat-type defects Corrugation wear Strain hardening
dc.subject.lemb.none.fl_str_mv	Ferrocarriles - Mantenimiento y reparación Transporte ferroviario - Medellín (Colombia) Vías férreas - Medellín (Colombia) Vías férreas - Mantenimiento y reparación Rieles (Ferrocarriles) - Mantenimiento y reparación
dc.subject.proposal.spa.fl_str_mv	Defectos tipo squat Desgaste ondulatorio Endurecimiento por deformación
dc.subject.proposal.eng.fl_str_mv	Squat-type defects Corrugation wear Strain hardening
description	Ilustraciones, fotografías, gráficas
publishDate	2024
dc.date.accessioned.none.fl_str_mv	2024-09-19T16:23:15Z
dc.date.available.none.fl_str_mv	2024-09-19T16:23:15Z
dc.date.issued.none.fl_str_mv	2024-09-18
dc.type.spa.fl_str_mv	Trabajo de grado - Maestría
dc.type.driver.spa.fl_str_mv	info:eu-repo/semantics/masterThesis
dc.type.version.spa.fl_str_mv	info:eu-repo/semantics/acceptedVersion
dc.type.content.spa.fl_str_mv	Text
dc.type.redcol.spa.fl_str_mv	http://purl.org/redcol/resource_type/TM
status_str	acceptedVersion
dc.identifier.uri.none.fl_str_mv	https://repositorio.unal.edu.co/handle/unal/86845
dc.identifier.instname.spa.fl_str_mv	Universidad Nacional de Colombia
dc.identifier.reponame.spa.fl_str_mv	Repositorio Institucional Universidad Nacional de Colombia
dc.identifier.repourl.spa.fl_str_mv	https://repositorio.unal.edu.co/
url	https://repositorio.unal.edu.co/handle/unal/86845 https://repositorio.unal.edu.co/
identifier_str_mv	Universidad Nacional de Colombia Repositorio Institucional Universidad Nacional de Colombia
dc.language.iso.spa.fl_str_mv	spa
language	spa
dc.relation.indexed.spa.fl_str_mv	LaReferencia
dc.relation.references.spa.fl_str_mv	Al-Juboori A. (2020). Mechanisms of squat initiation and propagation on rail surfaces. https://ro.uow.edu.au/theses1.https://ro.uow.edu.au/theses1/747 Al-Juboori, A., Wexler, D., Li, H., Zhu, H., Lu, C., McCusker, A., McLeod, J., Pannil, S., & Wang, Z. (2017). Squat formation and the occurrence of two distinct classes of white etching layer on the surface of rail steel. International Journal of Fatigue, 104, 52–60. https://doi.org/10.1016/j.ijfatigue.2017.07.005 Al-Juboori, A., Zhu, H., Wexler, D., Li, H., Lu, C., McCusker, A., McLeod, J., Pannila, S., & Barnes, J. (2019a). Characterisation of White Etching Layers formed on rails subjected to different traffic conditions. Wear, 436–437. https://doi.org/10.1016/j.wear.2019.202998 Al-Juboori, A., Zhu, H., Wexler, D., Li, H., Lu, C., McCusker, A., McLeod, J., Pannila, S., & Barnes, J. (2019b). Evolution of rail surface degradation in the tunnel: The role of water on squat growth under service conditions. Engineering Fracture Mechanics, 209, 32–47. https://doi.org/10.1016/j.engfracmech.2019.01.018 ASTM International. (2015). Standard Practice for Microetching Metals and Alloys (E407-07). https://doi.org/10.1520/E0407-07R15E01 ASTM International. (2017). Standard Guide for Preparation of Metallographic Specimens (E3-11). In ASTM. ASTM. https://doi.org/10.1520/E0003-11R17 Baumann, G., Fecht, H. J., & Liebelt, S. (1996). Formation of white-etching layers on rail treads. In Wear (Vol. 191). Bedoya-Zapata, D., Rojas-Parra, S., Díaz-Mazo, J. H., García-Jiménez, J. A., López-Londoño, J. E., Vergara-Puello, R. A., Molina, L. F., Santa-Marín, J. F., Toro, A., Mesaritis, M., Lewis, R., & Palacio, M. (2021). Case study: Understanding the formation of squat-type defects in a metropolitan railway. Engineering Failure Analysis, 123. https://doi.org/10.1016/j.engfailanal.2021.105325 Cho, H., & Park, J. (2021). Study of rail squat characteristics through analysis of train axle box acceleration frequency. Applied Sciences (Switzerland), 11(15). https://doi.org/10.3390/app11157022 Cho, H., Park, J., & Park, K. (2023). Analysis of Axial Acceleration for the Detection of Rail Squats in High-Speed Railways. CivilEng, 4(4), 1143–1156. https://doi.org/10.3390/civileng4040062 Clayton, P., & Allery, M. B. P. (1982). METALLURGICAL ASPECTS OF SURFACE DAMAGE PROBLEMS IN RAILS. In Canadian Metallurgical Quarterly (Vol. 21, Issue I). Deng, X., Li, Z., Qian, Z., Zhai, W., Xiao, Q., & Dollevoet, R. (2019). Pre-cracking development of weld-induced squats due to plastic deformation: Five-year field monitoring and numerical analysis. International Journal of Fatigue, 127, 431–444. https://doi.org/10.1016/j.ijfatigue.2019.06.013 Deng, X., Qian, Z., Li, Z., & Dollevoet, R. (2018). Investigation of the formation of corrugation-induced rail squats based on extensive field monitoring. International Journal of Fatigue, 112, 94–105. https://doi.org/10.1016/j.ijfatigue.2018.03.002 Dikshit, V., Clayton, P., & Christensen, D. (1991). Investigation of rolling contact fatigue in a head-hardened rail. In Wear* (Vol. 144). Du, X., Jin, X., Zhao, G., Wen, Z., & Li, W. (2021). Rail Corrugation of High-Speed Railway Induced by Rail Grinding. Shock and Vibration, 2021. https://doi.org/10.1155/2021/5546809 Farjoo, M., Daniel, W., & Meehan, P. A. (2012). Modelling a squat form crack on a rail laid on an elastic foundation. Engineering Fracture Mechanics, 85, 47–58. https://doi.org/10.1016/j.engfracmech.2012.02.004 Fröhling, R., De Koker, J., & Amade, M. (2009). Rail lubrication and its impact on the wheel/rail system. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 223(2), 173–180. https://doi.org/10.1243/09544097JRRT218 Grassie, S. L. (2012). Squats and squat-type defects in rails: The understanding to date. In Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit (Vol. 226, Issue 3, pp. 235–242). https://doi.org/10.1177/0954409711422189 Grassie, S. L. (2016). Studs and squats: The evolving story. Wear, 366–367, 194–199. https://doi.org/10.1016/j.wear.2016.03.021 Grassie, S. L., Fletcher, D. I., Gallardo Hernandez, E. A., & Summers, P. (2012). Studs: A squat-type defect in rails. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 226(3), 243–256. https://doi.org/10.1177/0954409711421462 Grassie, S. L., & Kalousek, J. (1993). Rail Corrugation: Characteristics, Causes and Treatments. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 207(1), 57–68. https://doi.org/10.1243/PIME_PROC_1993_207_227_02 Hajizad, O., Kumar, A., Li, Z., Petrov, R. H., Sietsma, J., & Dollevoet, R. (2019). Influence of microstructure on mechanical properties of bainitic steels in railway applications. Metals, 9(7). https://doi.org/10.3390/met9070778 Hasan, N. (2019). Shakedown Limits and Uses in Railroad Engineering. Journal of Materials in Civil Engineering, 31(11). https://doi.org/10.1061/(asce)mt.1943-5533.0002925 Johnson, K. L. (1985). Contact Mechanics. Cambridge University Press. https://doi.org/10.1017/CBO9781139171731 Jones, C. P., Tyfour, W. R., Beynon, J. H., & Kapoor, A. (n.d.). The effect of strain hardening on shakedown limits of a pearlitic rail steel. Kerr M, Wilson A, & Marich S. (2008). The epidemiology of squats and related rail defects. Conference on Railway Engineering. Lewis, R. (Roger), & Olofsson, U. (Ulf). (2009). Wheel-rail interface handbook. CRC Press. Li, S., Wu, J., Petrov, R. H., Li, Z., Dollevoet, R., & Sietsma, J. (2016). “Brown etching layer”: A possible new insight into the crack initiation of rolling contact fatigue in rail steels? Engineering Failure Analysis, 66, 8–18. https://doi.org/10.1016/j.engfailanal.2016.03.019 Li, Z., Dollevoet, R., Molodova, M., & Zhao, X. (2011). Squat growth-Some observations and the validation of numerical predictions. Wear, 271(1–2), 148–157. https://doi.org/10.1016/j.wear.2010.10.051 Li, Z., Molodova, M., Nunez, A., & Dollevoet, R. (2015). Improvements in axle box acceleration measurements for the detection of light squats in railway infrastructure. IEEE Transactions on Industrial Electronics, 62(7), 4385–4397. https://doi.org/10.1109/TIE.2015.2389761 Li, Z., Zhao, X., & Dollevoet, R. (2017). An approach to determine a critical size for rolling contact fatigue initiating from rail surface defects. International Journal of Rail Transportation, 5(1), 16–37. https://doi.org/10.1080/23248378.2016.1194775 Li, Z., Zhao, X., Dollevoet, R., & Molodova, M. (2008). Differential wear and plastic deformation as causes of squat at track local stiffness change combined with other track short defects. Vehicle System Dynamics, 46(SUPPL.1), 237–246. https://doi.org/10.1080/00423110801935855 Li, Z., Zhao, X., Esveld, C., Dollevoet, R., & Molodova, M. (2008). An investigation into the causes of squats-Correlation analysis and numerical modeling. Wear, 265(9–10), 1349–1355. https://doi.org/10.1016/j.wear.2008.02.037 Mesaritis, M., Santa, J. F., Molina, L. F., Palacio, M., Toro, A., & Lewis, R. (2023). Post-field grinding evaluation of different rail grades in full-scale wheel/rail laboratory tests. Tribology International, 177. https://doi.org/10.1016/j.triboint.2022.107980 Messaadi, M., & Steenbergen, M. (2018). Stratified surface layers on rails. Wear, 414–415, 151–162. https://doi.org/10.1016/j.wear.2018.07.019 Molodova, M., Li, Z., Nunez, A., & Dollevoet, R. (2014). Automatic detection of squats in railway infrastructure. IEEE Transactions on Intelligent Transportation Systems, 15(5), 1980–1990. https://doi.org/10.1109/TITS.2014.2307955 Naeimi, M., Li, Z., & Dollevoet, R. (2015). Nucleation of squat cracks in rail, calculation of crack initiation angles in three dimensions. Journal of Physics: Conference Series, 628(1). https://doi.org/10.1088/1742-6596/628/1/012043 Naeimi, M., Li, Z., Qian, Z., Zhou, Y., Wu, J., Petrov, R. H., Sietsma, J., & Dollevoet, R. (2017). Reconstruction of the rolling contact fatigue cracks in rails using X-ray computed tomography. NDT and E International, 92, 199–212. https://doi.org/10.1016/j.ndteint.2017.09.004 Pablo Restrepo-Barrientos. (2024). Dynamic modelling of track-vehicle interaction in railway systems: effect of elastic properties of the track and substructure. Universidad Nacional De Colombia. Pal, S., Valente, C., Daniel, W., & Farjoo, M. (2012). Metallurgical and physical understanding of rail squat initiation and propagation. Wear, 284–285, 30–42. https://doi.org/10.1016/j.wear.2012.02.013 Paloma Vila Tortosa. (2015). Modelado del crecimiento del desgaste ondulatorio en carriles ferroviarios. Universitat Politècnica de València. Pereira, J. I., Tressia, G., Kina, E. J., Sinatora, A., & Souza, R. M. (2021a). Analysis of subsurface layer formation on a pearlitic rail under heavy haul conditions: Spalling characterization. Engineering Failure Analysis, 130. https://doi.org/10.1016/j.engfailanal.2021.105549 Pereira, J. I., Tressia, G., Kina, E. J., Sinatora, A., & Souza, R. M. (2021b). Analysis of subsurface layer formation on a pearlitic rail under heavy haul conditions: Spalling characterization. Engineering Failure Analysis, 130. https://doi.org/10.1016/j.engfailanal.2021.105549 Smulders. (2003, July 1). Management and research tackle rolling contact fatigue. Railway Gazette International. Steenbergen, M., & Dollevoet, R. (2013a). On the mechanism of squat formation on train rails - Part I: Origination. International Journal of Fatigue, 47, 361–372. https://doi.org/10.1016/j.ijfatigue.2012.04.023 Steenbergen, M., & Dollevoet, R. (2013b). On the mechanism of squat formation on train rails - Part II: Growth. International Journal of Fatigue, 47, 373–381. https://doi.org/10.1016/j.ijfatigue.2012.04.019 UNE. (2012). Aplicaciones ferroviarias Vía Carriles Parte 1: Carriles Vignole de masa mayor o igual a 46 kg/m (EN 13674-1). In UNE. Wu, J., Petrov, R. H., Naeimi, M., Li, Z., Dollevoet, R., & Sietsma, J. (2016). Laboratory simulation of martensite formation of white etching layer in rail steel. International Journal of Fatigue, 91, 11–20. https://doi.org/10.1016/j.ijfatigue.2016.05.016 Yuan, Z., Zhu, S., Chang, C., Yuan, X., Zhang, Q., & Zhai, W. (2021). An unsupervised method based on convolutional variational auto-encoder and anomaly detection algorithms for light rail squat localization. Construction and Building Materials, 313. https://doi.org/10.1016/j.conbuildmat.2021.125563 Zhang, H., Zhang, S. Y., Zhong, H., Wang, W. J., Meli, E., Cui, X. L., Ding, H. H., & Liu, Q. Y. (2022). Damage mechanism of a long-wavelength corrugated rail associated with rolling contact fatigue. Engineering Failure Analysis, 136. https://doi.org/10.1016/j.engfailanal.2022.106173 Zhao, X., Li, Z., & Dollevoet, R. (2013). The vertical and the longitudinal dynamic responses of the vehicle-track system to squat-type short wavelength irregularity. Vehicle System Dynamics, 51(12), 1918–1937. https://doi.org/10.1080/00423114.2013.847466 Zhu, H., Li, H., Al-Juboori, A., Wexler, D., Lu, C., McCusker, A., McLeod, J., Pannila, S., & Barnes, J. (2020). Understanding and treatment of squat defects in a railway network. Wear, 442–443, 203139. https://doi.org/10.1016/j.wear.2019.203139
dc.rights.coar.fl_str_mv	http://purl.org/coar/access_right/c_abf2
dc.rights.license.spa.fl_str_mv	Atribución-NoComercial-SinDerivadas 4.0 Internacional
dc.rights.uri.spa.fl_str_mv	http://creativecommons.org/licenses/by-nc-nd/4.0/
dc.rights.accessrights.spa.fl_str_mv	info:eu-repo/semantics/openAccess
rights_invalid_str_mv	Atribución-NoComercial-SinDerivadas 4.0 Internacional http://creativecommons.org/licenses/by-nc-nd/4.0/ http://purl.org/coar/access_right/c_abf2
eu_rights_str_mv	openAccess
dc.format.extent.spa.fl_str_mv	96 páginas
dc.format.mimetype.spa.fl_str_mv	application/pdf
dc.coverage.city.none.fl_str_mv	Medellín (Antioquia, Colombia)
dc.publisher.spa.fl_str_mv	Universidad Nacional de Colombia
dc.publisher.program.spa.fl_str_mv	Medellín - Minas - Maestría en Ingeniería - Materiales y Procesos
dc.publisher.faculty.spa.fl_str_mv	Facultad de Minas
dc.publisher.place.spa.fl_str_mv	Medellín, Colombia
dc.publisher.branch.spa.fl_str_mv	Universidad Nacional de Colombia - Sede Medellín
institution	Universidad Nacional de Colombia
bitstream.url.fl_str_mv	https://repositorio.unal.edu.co/bitstream/unal/86845/1/license.txt https://repositorio.unal.edu.co/bitstream/unal/86845/2/1152469557_2024.pdf https://repositorio.unal.edu.co/bitstream/unal/86845/3/1152469557_2024.pdf.jpg
bitstream.checksum.fl_str_mv	eb34b1cf90b7e1103fc9dfd26be24b4a 979038532efe81291453e57e883adf59 4094a1a639a90a14b06f59adbdae299a
bitstream.checksumAlgorithm.fl_str_mv	MD5 MD5 MD5
repository.name.fl_str_mv	Repositorio Institucional Universidad Nacional de Colombia
repository.mail.fl_str_mv	repositorio_nal@unal.edu.co
_version_	1812169385850175488
spelling	Atribución-NoComercial-SinDerivadas 4.0 Internacionalhttp://creativecommons.org/licenses/by-nc-nd/4.0/info:eu-repo/semantics/openAccesshttp://purl.org/coar/access_right/c_abf2Toro, Alejandrocaada36313e95f5bd4f0bac9cc17128aGarcía Jiménez, Jose Alejandro972fde0214f4bd78883cbf3917940b5aGrupo de Tribología y SuperficiesGarcía Jiménez, Jose Alejandro [0000-0002-2549-9982]Jose A. García-Jiménez2024-09-19T16:23:15Z2024-09-19T16:23:15Z2024-09-18https://repositorio.unal.edu.co/handle/unal/86845Universidad Nacional de ColombiaRepositorio Institucional Universidad Nacional de Colombiahttps://repositorio.unal.edu.co/Ilustraciones, fotografías, gráficasEn los últimos años se han aumentado los reportes de aparición de defectos tipo squat en los rieles de la Línea A del metro de Medellín. Este incremento representa un riesgo para la seguridad del servicio y el confort del usuario, haciendo de este un objeto de estudio importante. Esta investigación se centra en conocer las características superficiales y microestructurales que describen los defectos tipo squat. Con el fin de estudiar estos defectos, se analizaron tres defectos tipo squat en los rieles de las curvas 35 y 96 de la Línea A del Metro de Medellín. Las técnicas que fueron utilizadas para la caracterización de los defectos estudiados son: Microscopia Óptica, Microscopia Electrónica de Barrido (en inglés: Sacanning Electron Microscopy SEM), medidas de dureza y microdurezas en Vickers y medida de perfil de rugosidad. Además, se midió el desgaste ondulatorio en las curvas 35 y 96, antes de que fueran retiradas de servicio, por medio de un análisis de CAT (Corrugation Analysis Trolley) que describe las longitudes de onda en función de la posición recorrida. Se encontró regiones de capa blanca (en inglés: White Etching Layer WEL) y altas deformaciones plásticas en las superficies de las muestras analizadas. Las deformaciones plásticas fueron comparadas a partir de medidas de dureza en zonas con y sin ensanchamiento en la banda de rodadura, algunas zonas con un incremento en la dureza de hasta 130 HV por encima del valor nominal. Luego, en el mapa de estabilización (en inglés: shakedown map) fueron analizados para conocer si se encuentran en la zona de colapso de material. Adicionalmente, se encontró longitudes de onda críticas en el desgaste ondulatorio entre 20-40 mm por medio de las mediciones en el CAT para las curvas 35 y 96. (Tomado de la fuente)In recent years, reports of squat-type defects in the rails of Line A of the Medellín Metro have increased. This rise represents a significant risk to the safety and comfort of passengers, making it essential to study this phenomenon thoroughly. This research focuses on understanding the surface and microstructural characteristics that define squattype defects. To investigate these phenomena, three rail defects from curves 35 and 96 of the Line A from Medellin’s Metro were analyzed. The techniques employed for the characterization included Optical Microscopy, Scanning Electron Microscopy, Vickers hardness and microhardness testing, and surface roughness profiling. Additionally, rail corrugation measurements were done in curves 35 and 96 using a Corrugation Analysis Trolley (CAT) before these rail sections were removed from service. The CAT analysis provided data on wavelength variations along the track. The study identified regions of White Etching Layer (WEL) and significant plastic deformation on the analyzed surfaces. Plastic deformations were compared through a hardness analysis in areas with and without widening of the running band, with some regions showing an increase in hardness of up to 130 HV above the nominal value. These deformations were then analyzed using a shakedown map to determine if they belonged to the material collapse zone. These deformations were then analyzed using a shakedown map to determine if they belonged to the material collapse zone. Furthermore, critical wavelengths between 20-40 mm were identified through the rail corrugation with CAT on curves 35 and 96.MaestríaMagíster en Ingeniería - Materiales y ProcesosMaterialesSuperficiesMateriales Y Nanotecnología.Sede Medellín96 páginasapplication/pdfspaUniversidad Nacional de ColombiaMedellín - Minas - Maestría en Ingeniería - Materiales y ProcesosFacultad de MinasMedellín, ColombiaUniversidad Nacional de Colombia - Sede Medellín620 - Ingeniería y operaciones afines::625 - Ingeniería de ferrocarriles y de carreteraFerrocarriles - Mantenimiento y reparaciónTransporte ferroviario - Medellín (Colombia)Vías férreas - Medellín (Colombia)Vías férreas - Mantenimiento y reparaciónRieles (Ferrocarriles) - Mantenimiento y reparaciónDefectos tipo squatDesgaste ondulatorioEndurecimiento por deformaciónSquat-type defectsCorrugation wearStrain hardeningEstudio de los defectos tipo squat en los rieles del Metro de MedellínStudy of squat-type defects in the rails of the Medellín MetroTrabajo de grado - Maestríainfo:eu-repo/semantics/masterThesisinfo:eu-repo/semantics/acceptedVersionTexthttp://purl.org/redcol/resource_type/TMMedellín (Antioquia, Colombia)LaReferenciaAl-Juboori A. (2020). Mechanisms of squat initiation and propagation on rail surfaces. https://ro.uow.edu.au/theses1.https://ro.uow.edu.au/theses1/747Al-Juboori, A., Wexler, D., Li, H., Zhu, H., Lu, C., McCusker, A., McLeod, J., Pannil, S., & Wang, Z. (2017). Squat formation and the occurrence of two distinct classes of white etching layer on the surface of rail steel. International Journal of Fatigue, 104, 52–60. https://doi.org/10.1016/j.ijfatigue.2017.07.005Al-Juboori, A., Zhu, H., Wexler, D., Li, H., Lu, C., McCusker, A., McLeod, J., Pannila, S., & Barnes, J. (2019a). Characterisation of White Etching Layers formed on rails subjected to different traffic conditions. Wear, 436–437. https://doi.org/10.1016/j.wear.2019.202998Al-Juboori, A., Zhu, H., Wexler, D., Li, H., Lu, C., McCusker, A., McLeod, J., Pannila, S., & Barnes, J. (2019b). Evolution of rail surface degradation in the tunnel: The role of water on squat growth under service conditions. Engineering Fracture Mechanics, 209, 32–47. https://doi.org/10.1016/j.engfracmech.2019.01.018ASTM International. (2015). Standard Practice for Microetching Metals and Alloys (E407-07). https://doi.org/10.1520/E0407-07R15E01ASTM International. (2017). Standard Guide for Preparation of Metallographic Specimens (E3-11). In ASTM. ASTM. https://doi.org/10.1520/E0003-11R17Baumann, G., Fecht, H. J., & Liebelt, S. (1996). Formation of white-etching layers on rail treads. In Wear (Vol. 191).Bedoya-Zapata, D., Rojas-Parra, S., Díaz-Mazo, J. H., García-Jiménez, J. A., López-Londoño, J. E., Vergara-Puello, R. A., Molina, L. F., Santa-Marín, J. F., Toro, A., Mesaritis, M., Lewis, R., & Palacio, M. (2021). Case study: Understanding the formation of squat-type defects in a metropolitan railway. Engineering Failure Analysis, 123. https://doi.org/10.1016/j.engfailanal.2021.105325Cho, H., & Park, J. (2021). Study of rail squat characteristics through analysis of train axle box acceleration frequency. Applied Sciences (Switzerland), 11(15). https://doi.org/10.3390/app11157022Cho, H., Park, J., & Park, K. (2023). Analysis of Axial Acceleration for the Detection of Rail Squats in High-Speed Railways. CivilEng, 4(4), 1143–1156. https://doi.org/10.3390/civileng4040062Clayton, P., & Allery, M. B. P. (1982). METALLURGICAL ASPECTS OF SURFACE DAMAGE PROBLEMS IN RAILS. In Canadian Metallurgical Quarterly (Vol. 21, Issue I).Deng, X., Li, Z., Qian, Z., Zhai, W., Xiao, Q., & Dollevoet, R. (2019). Pre-cracking development of weld-induced squats due to plastic deformation: Five-year field monitoring and numerical analysis. International Journal of Fatigue, 127, 431–444. https://doi.org/10.1016/j.ijfatigue.2019.06.013Deng, X., Qian, Z., Li, Z., & Dollevoet, R. (2018). Investigation of the formation of corrugation-induced rail squats based on extensive field monitoring. International Journal of Fatigue, 112, 94–105. https://doi.org/10.1016/j.ijfatigue.2018.03.002Dikshit, V., Clayton, P., & Christensen, D. (1991). Investigation of rolling contact fatigue in a head-hardened rail. In Wear* (Vol. 144).Du, X., Jin, X., Zhao, G., Wen, Z., & Li, W. (2021). Rail Corrugation of High-Speed Railway Induced by Rail Grinding. Shock and Vibration, 2021. https://doi.org/10.1155/2021/5546809Farjoo, M., Daniel, W., & Meehan, P. A. (2012). Modelling a squat form crack on a rail laid on an elastic foundation. Engineering Fracture Mechanics, 85, 47–58. https://doi.org/10.1016/j.engfracmech.2012.02.004Fröhling, R., De Koker, J., & Amade, M. (2009). Rail lubrication and its impact on the wheel/rail system. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 223(2), 173–180. https://doi.org/10.1243/09544097JRRT218Grassie, S. L. (2012). Squats and squat-type defects in rails: The understanding to date. In Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit (Vol. 226, Issue 3, pp. 235–242). https://doi.org/10.1177/0954409711422189Grassie, S. L. (2016). Studs and squats: The evolving story. Wear, 366–367, 194–199. https://doi.org/10.1016/j.wear.2016.03.021Grassie, S. L., Fletcher, D. I., Gallardo Hernandez, E. A., & Summers, P. (2012). Studs: A squat-type defect in rails. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 226(3), 243–256. https://doi.org/10.1177/0954409711421462Grassie, S. L., & Kalousek, J. (1993). Rail Corrugation: Characteristics, Causes and Treatments. Proceedings of the Institution of Mechanical Engineers, Part F: Journal of Rail and Rapid Transit, 207(1), 57–68. https://doi.org/10.1243/PIME_PROC_1993_207_227_02Hajizad, O., Kumar, A., Li, Z., Petrov, R. H., Sietsma, J., & Dollevoet, R. (2019). Influence of microstructure on mechanical properties of bainitic steels in railway applications. Metals, 9(7). https://doi.org/10.3390/met9070778Hasan, N. (2019). Shakedown Limits and Uses in Railroad Engineering. Journal of Materials in Civil Engineering, 31(11). https://doi.org/10.1061/(asce)mt.1943-5533.0002925Johnson, K. L. (1985). Contact Mechanics. Cambridge University Press. https://doi.org/10.1017/CBO9781139171731Jones, C. P., Tyfour, W. R., Beynon, J. H., & Kapoor, A. (n.d.). The effect of strain hardening on shakedown limits of a pearlitic rail steel.Kerr M, Wilson A, & Marich S. (2008). The epidemiology of squats and related rail defects. Conference on Railway Engineering.Lewis, R. (Roger), & Olofsson, U. (Ulf). (2009). Wheel-rail interface handbook. CRC Press.Li, S., Wu, J., Petrov, R. H., Li, Z., Dollevoet, R., & Sietsma, J. (2016). “Brown etching layer”: A possible new insight into the crack initiation of rolling contact fatigue in rail steels? Engineering Failure Analysis, 66, 8–18. https://doi.org/10.1016/j.engfailanal.2016.03.019Li, Z., Dollevoet, R., Molodova, M., & Zhao, X. (2011). Squat growth-Some observations and the validation of numerical predictions. Wear, 271(1–2), 148–157. https://doi.org/10.1016/j.wear.2010.10.051Li, Z., Molodova, M., Nunez, A., & Dollevoet, R. (2015). Improvements in axle box acceleration measurements for the detection of light squats in railway infrastructure. IEEE Transactions on Industrial Electronics, 62(7), 4385–4397. https://doi.org/10.1109/TIE.2015.2389761Li, Z., Zhao, X., & Dollevoet, R. (2017). An approach to determine a critical size for rolling contact fatigue initiating from rail surface defects. International Journal of Rail Transportation, 5(1), 16–37. https://doi.org/10.1080/23248378.2016.1194775Li, Z., Zhao, X., Dollevoet, R., & Molodova, M. (2008). Differential wear and plastic deformation as causes of squat at track local stiffness change combined with other track short defects. Vehicle System Dynamics, 46(SUPPL.1), 237–246. https://doi.org/10.1080/00423110801935855Li, Z., Zhao, X., Esveld, C., Dollevoet, R., & Molodova, M. (2008). An investigation into the causes of squats-Correlation analysis and numerical modeling. Wear, 265(9–10), 1349–1355. https://doi.org/10.1016/j.wear.2008.02.037Mesaritis, M., Santa, J. F., Molina, L. F., Palacio, M., Toro, A., & Lewis, R. (2023). Post-field grinding evaluation of different rail grades in full-scale wheel/rail laboratory tests. Tribology International, 177. https://doi.org/10.1016/j.triboint.2022.107980Messaadi, M., & Steenbergen, M. (2018). Stratified surface layers on rails. Wear, 414–415, 151–162. https://doi.org/10.1016/j.wear.2018.07.019Molodova, M., Li, Z., Nunez, A., & Dollevoet, R. (2014). Automatic detection of squats in railway infrastructure. IEEE Transactions on Intelligent Transportation Systems, 15(5), 1980–1990. https://doi.org/10.1109/TITS.2014.2307955Naeimi, M., Li, Z., & Dollevoet, R. (2015). Nucleation of squat cracks in rail, calculation of crack initiation angles in three dimensions. Journal of Physics: Conference Series, 628(1). https://doi.org/10.1088/1742-6596/628/1/012043Naeimi, M., Li, Z., Qian, Z., Zhou, Y., Wu, J., Petrov, R. H., Sietsma, J., & Dollevoet, R. (2017). Reconstruction of the rolling contact fatigue cracks in rails using X-ray computed tomography. NDT and E International, 92, 199–212. https://doi.org/10.1016/j.ndteint.2017.09.004Pablo Restrepo-Barrientos. (2024). Dynamic modelling of track-vehicle interaction in railway systems: effect of elastic properties of the track and substructure. Universidad Nacional De Colombia.Pal, S., Valente, C., Daniel, W., & Farjoo, M. (2012). Metallurgical and physical understanding of rail squat initiation and propagation. Wear, 284–285, 30–42. https://doi.org/10.1016/j.wear.2012.02.013Paloma Vila Tortosa. (2015). Modelado del crecimiento del desgaste ondulatorio en carriles ferroviarios. Universitat Politècnica de València.Pereira, J. I., Tressia, G., Kina, E. J., Sinatora, A., & Souza, R. M. (2021a). Analysis of subsurface layer formation on a pearlitic rail under heavy haul conditions: Spalling characterization. Engineering Failure Analysis, 130. https://doi.org/10.1016/j.engfailanal.2021.105549Pereira, J. I., Tressia, G., Kina, E. J., Sinatora, A., & Souza, R. M. (2021b). Analysis of subsurface layer formation on a pearlitic rail under heavy haul conditions: Spalling characterization. Engineering Failure Analysis, 130. https://doi.org/10.1016/j.engfailanal.2021.105549Smulders. (2003, July 1). Management and research tackle rolling contact fatigue. Railway Gazette International.Steenbergen, M., & Dollevoet, R. (2013a). On the mechanism of squat formation on train rails - Part I: Origination. International Journal of Fatigue, 47, 361–372. https://doi.org/10.1016/j.ijfatigue.2012.04.023Steenbergen, M., & Dollevoet, R. (2013b). On the mechanism of squat formation on train rails - Part II: Growth. International Journal of Fatigue, 47, 373–381. https://doi.org/10.1016/j.ijfatigue.2012.04.019UNE. (2012). Aplicaciones ferroviarias Vía Carriles Parte 1: Carriles Vignole de masa mayor o igual a 46 kg/m (EN 13674-1). In UNE.Wu, J., Petrov, R. H., Naeimi, M., Li, Z., Dollevoet, R., & Sietsma, J. (2016). Laboratory simulation of martensite formation of white etching layer in rail steel. International Journal of Fatigue, 91, 11–20. https://doi.org/10.1016/j.ijfatigue.2016.05.016Yuan, Z., Zhu, S., Chang, C., Yuan, X., Zhang, Q., & Zhai, W. (2021). An unsupervised method based on convolutional variational auto-encoder and anomaly detection algorithms for light rail squat localization. Construction and Building Materials, 313. https://doi.org/10.1016/j.conbuildmat.2021.125563Zhang, H., Zhang, S. Y., Zhong, H., Wang, W. J., Meli, E., Cui, X. L., Ding, H. H., & Liu, Q. Y. (2022). Damage mechanism of a long-wavelength corrugated rail associated with rolling contact fatigue. Engineering Failure Analysis, 136. https://doi.org/10.1016/j.engfailanal.2022.106173Zhao, X., Li, Z., & Dollevoet, R. (2013). The vertical and the longitudinal dynamic responses of the vehicle-track system to squat-type short wavelength irregularity. Vehicle System Dynamics, 51(12), 1918–1937. https://doi.org/10.1080/00423114.2013.847466Zhu, H., Li, H., Al-Juboori, A., Wexler, D., Lu, C., McCusker, A., McLeod, J., Pannila, S., & Barnes, J. (2020). Understanding and treatment of squat defects in a railway network. Wear, 442–443, 203139. https://doi.org/10.1016/j.wear.2019.203139EstudiantesInvestigadoresPúblico generalLICENSElicense.txtlicense.txttext/plain; charset=utf-85879https://repositorio.unal.edu.co/bitstream/unal/86845/1/license.txteb34b1cf90b7e1103fc9dfd26be24b4aMD51ORIGINAL1152469557_2024.pdf1152469557_2024.pdfTesis de Maestría en Ingeniería - Materiales y Procesosapplication/pdf6480744https://repositorio.unal.edu.co/bitstream/unal/86845/2/1152469557_2024.pdf979038532efe81291453e57e883adf59MD52THUMBNAIL1152469557_2024.pdf.jpg1152469557_2024.pdf.jpgGenerated Thumbnailimage/jpeg3951https://repositorio.unal.edu.co/bitstream/unal/86845/3/1152469557_2024.pdf.jpg4094a1a639a90a14b06f59adbdae299aMD53unal/86845oai:repositorio.unal.edu.co:unal/868452024-09-19 23:10:08.989Repositorio Institucional Universidad Nacional de Colombiarepositorio_nal@unal.edu.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

Estudio de los defectos tipo squat en los rieles del Metro de Medellín

Publicaciones similares