• Proceedings of the KSR Conference
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• 2010.06a
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• pp.315-323
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• 2010

It is suggested that the service life of the continuous welded rail(CWR) is estimated by the relationship between the rail surface irregularity according to the accumulated passing tonnage and bending fatigue of welded part in CWR. In this study, it measured bending stress of rail according to the rail surface irregularity in the concrete track on the Seoul Metro. In addition, the relationship between rail surface irregularity and bending stress in concrete track is analyzed by results of the field test. Finally, this study clarified the relationship among bending stress(Y) of rail, train speed(U), rail surface irregularity(v, w) in concrete track. The result of this study is able to use the basis data to establishing the periodic replacements criterion of CWR.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.988-991
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• 2006

Rolling Stock running are making Rail Head Surface damage(corrugation, flaking, shelling, etc). It's coming out Rail Head Surface Irregularity. It increases Rolling Stock and structure vibration. Therefore, this paper analyzes the influence of Rail Head Surface Irregularity to railway vibration. And, It introduces the management method of Rail Head Surface and proposes its R&D direction in railway-run organization.

• Journal of the Korean Society for Railway
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• v.14 no.6
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• pp.535-544
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• 2011

The rail surface defects can cause the high impact load on the track and lead to the progress of the rail fatigue damage and the rail break. In case of the rail break, there is a great deal of risk for derailment, and thus the maintenance criteria for the rail surface defects are of great importance. In this study, using the dynamic train-track interaction analysis program, the impact wheel loads and rail bending stresses according to the depths of the surface defects have been calculated with the input data of the rail surface irregularities measured at 43 spots with surface defects in the ballasted track of high-speed railway. Considering the irregularity of track geometry, the allowable limits of wheel load and rail bending stress have been set, and the maintenance criteria for the rail surface defects was suggested by analyzing the relationship of the maximum values of wheel load and rail bending stress versus depth and width of rail surface defect. The analysis results suggest that the allowable depth of the surface defect is determined approximately 0.2mm from the limit of the impact wheel load.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.64-71
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• 2010

It is suggested that the service life of the continuous welded rail(CWR) is estimated by the relationship between the rail surface irregularity according to the accumulated passing tonnage and bending fatigue of welded part in CWR. In this study, based on the results of bending fatigue tests of rail and results of measuring tests in situ of rail bending stress, this study estimated the bending fatigue life of welded rail in concrete track, adopting a Haibach's rule. The bending fatigue life of CWR considered the rail surface irregularity, train speed and the S-N curve by types of rail welding. In addition, this study estimated it for the fracture probability 1%, 0.1%, 0.01%. Therefore, this study proposed bending fatigue life of CWR in concrete track.

• Proceedings of the KSR Conference
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• 2009.05b
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• pp.369-375
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• 2009

The Periodic replacements criterion of rail is calculated on the basis of the research result of RTRI in Japan. It is suggested that the service life of the continuous welded rail(CWR) is estimated by the relationship between the rail surface irregularity according to the accumulated passing tonnage and bending fatigue of welded part in CWR. In order to establish the periodic replacements criterion of CWR, this study measured the rail surface irregularity according to the accumulated passing tonnage, the types of track system and welding. Therefore, it is analyzed that the gas pressure welding is the worst one of the others. In addition, it is analyzed that the rail surface irregularity growth rate in ballast track is about $0.02{\sim}0.03mm$/100MGT and its in concrete track is about $0.005{\sim}0.02mm$/100MGT Finally, the result of this study is able to use the basis data to establishing the periodic replacements criterion of CWR considering rail grinding.