The impact of deformation in the zone of welded joints on the force action of the rolling stock on the track

The causes of deformation in the zone of welded joints are considered. Authors experimentally studied changes in hardness on the rolling surface of the rail in the longitudinal and transverse profiles within the thermally affected zone of the welded joint. It is established that the hardness of the...

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Main Authors: V. S. Kossov, O. G. Krasnov, M. G. Akashev
Format: Article
Language:Russian
Published: Joint Stock Company «Railway Scientific and Research Institute» 2020-03-01
Series:Вестник Научно-исследовательского института железнодорожного транспорта
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Online Access:https://www.journal-vniizht.ru/jour/article/view/382
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author V. S. Kossov
O. G. Krasnov
M. G. Akashev
author_facet V. S. Kossov
O. G. Krasnov
M. G. Akashev
author_sort V. S. Kossov
collection DOAJ
description The causes of deformation in the zone of welded joints are considered. Authors experimentally studied changes in hardness on the rolling surface of the rail in the longitudinal and transverse profiles within the thermally affected zone of the welded joint. It is established that the hardness of the rolling surface of the rail in the longitudinal direction in the thermally affected zone of the joint is uneven and is determined by the structures arising from the effects of the thermal cycles of welding and the quality of the local heat treatment. In this case, two "low spots" are clearly traced with a decrease in hardness to 290...300 HB and with a higher hardness up to 350 HB right in the welded joint. Experimentally investigated the change in the depth of the welded joint from the implemented tonnage. At the same time with strain gauge method, using the force method developed by N. N. Kudryavtsev, continuous changes in vertical forces when the wheels move along the welded joint zone were recorded. Average values of vertical forces from loaded cars were established. Experimental distributions of vertical forces were approximated by theoretical laws according to the Kolmogorov — Smirnov matching criterion. Recommendations are given on minimizing the harmful impact of rolling stock on the track in areas of lowering welded joints.The following conclusions were made.1.            Geometry of the joint irregularity is in the form of a W-shaped deformation with an influx of metal on the receiving rail and lowering on the directing rail. The width of the upper part of the deformation varies between 160...200 mm along the axis of the rail.2.            Deformation zone of the welded joint is a source of increased dynamic impact from the wheels of the rolling stock on the elements of the upper track structure. According to the results of experimental studies it was found that the greatest increase in dynamic effects was observed from locomotive wheels up to 45..               . 70 kN, maximum values reached 180...210 kN, from the wheels of loaded freight cars the values of vertical forces increased by 35..     .45 kN, maximum values reached 145...170 kN, from the wheels of empty cars increase dynamic impacts amounted to 14...16 kN, maximum values reached 32...36 kN.
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id doaj-art-ccb13c70fbc24c1f92be8dd968cf9e14
institution Kabale University
issn 2223-9731
2713-2560
language Russian
publishDate 2020-03-01
publisher Joint Stock Company «Railway Scientific and Research Institute»
record_format Article
series Вестник Научно-исследовательского института железнодорожного транспорта
spelling doaj-art-ccb13c70fbc24c1f92be8dd968cf9e142025-08-20T03:59:08ZrusJoint Stock Company «Railway Scientific and Research Institute»Вестник Научно-исследовательского института железнодорожного транспорта2223-97312713-25602020-03-0179191610.21780/2223-9731-2020-79-1-9-16271The impact of deformation in the zone of welded joints on the force action of the rolling stock on the trackV. S. Kossov0O. G. Krasnov1M. G. Akashev2Joint Stock Company "Research and Design Institute of Rolling Stock" (JSC "VNIKTI")Joint Stock Company "Research and Design Institute of Rolling Stock" (JSC "VNIKTI")Joint Stock Company "Research and Design Institute of Rolling Stock" (JSC "VNIKTI")The causes of deformation in the zone of welded joints are considered. Authors experimentally studied changes in hardness on the rolling surface of the rail in the longitudinal and transverse profiles within the thermally affected zone of the welded joint. It is established that the hardness of the rolling surface of the rail in the longitudinal direction in the thermally affected zone of the joint is uneven and is determined by the structures arising from the effects of the thermal cycles of welding and the quality of the local heat treatment. In this case, two "low spots" are clearly traced with a decrease in hardness to 290...300 HB and with a higher hardness up to 350 HB right in the welded joint. Experimentally investigated the change in the depth of the welded joint from the implemented tonnage. At the same time with strain gauge method, using the force method developed by N. N. Kudryavtsev, continuous changes in vertical forces when the wheels move along the welded joint zone were recorded. Average values of vertical forces from loaded cars were established. Experimental distributions of vertical forces were approximated by theoretical laws according to the Kolmogorov — Smirnov matching criterion. Recommendations are given on minimizing the harmful impact of rolling stock on the track in areas of lowering welded joints.The following conclusions were made.1.            Geometry of the joint irregularity is in the form of a W-shaped deformation with an influx of metal on the receiving rail and lowering on the directing rail. The width of the upper part of the deformation varies between 160...200 mm along the axis of the rail.2.            Deformation zone of the welded joint is a source of increased dynamic impact from the wheels of the rolling stock on the elements of the upper track structure. According to the results of experimental studies it was found that the greatest increase in dynamic effects was observed from locomotive wheels up to 45..               . 70 kN, maximum values reached 180...210 kN, from the wheels of loaded freight cars the values of vertical forces increased by 35..     .45 kN, maximum values reached 145...170 kN, from the wheels of empty cars increase dynamic impacts amounted to 14...16 kN, maximum values reached 32...36 kN.https://www.journal-vniizht.ru/jour/article/view/382welded jointthermally affected zonerolling surface hardnessvertical forcestheoretical laws of distribution
spellingShingle V. S. Kossov
O. G. Krasnov
M. G. Akashev
The impact of deformation in the zone of welded joints on the force action of the rolling stock on the track
Вестник Научно-исследовательского института железнодорожного транспорта
welded joint
thermally affected zone
rolling surface hardness
vertical forces
theoretical laws of distribution
title The impact of deformation in the zone of welded joints on the force action of the rolling stock on the track
title_full The impact of deformation in the zone of welded joints on the force action of the rolling stock on the track
title_fullStr The impact of deformation in the zone of welded joints on the force action of the rolling stock on the track
title_full_unstemmed The impact of deformation in the zone of welded joints on the force action of the rolling stock on the track
title_short The impact of deformation in the zone of welded joints on the force action of the rolling stock on the track
title_sort impact of deformation in the zone of welded joints on the force action of the rolling stock on the track
topic welded joint
thermally affected zone
rolling surface hardness
vertical forces
theoretical laws of distribution
url https://www.journal-vniizht.ru/jour/article/view/382
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