• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.547-552
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• 2022

In this study, shape-based track management by analyzing track irregularity was studied in terms of force-based track irregularity analysis by numerical analysis of wheel-rail interaction force using by the measured vertical irregularity. The effect of the vertical irregularity of the track due to the difference in track types on the wheel-rail interaction force and the track acceleration in the connecting section of the sleeper floating track and the direct fixation track on concrete bed were analyzed. As the results of this study, the measured vertical irregularity was directly affect the vertical wheel load (the wheel-rail interaction force) and the rail acceleration, and it has been demonstrated to change consistently. In this study, the adequacy and necessity of the force-based track irregularity analysis method was verified based on the wheel-rail interaction analysis using the the measured vertical irregularity.

• Journal of the Korean Society for Railway
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• v.17 no.1
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• pp.14-18
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• 2014

Wheel/rail contact is a significant problem in railway dynamics. In this paper, the wheel/rail contact is examined analytically and numerically as a contact problem between two cylinders where torque and friction have effect. Furthermore, the contact of a real wheel and rail is investigated numerically where the normal and shear force act. This study demonstrates that the wheel/rail contact is a process that generates traction force through creep where rolling and sliding occurs simultaneously depending on the shape of the wheel and rail, and the friction coefficient between them.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2004.05a
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• pp.176-176
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• 2004

21세기 고속철도시대에 진입하면서 차량고속화에 수반하여 주행안전성 면에서 빼놓을 수 없는 문제로 가장 중요한 탈선의 현상이 있다. 철도에 있어서 탈선은 대형사고로 직결되기 때문에 결코 쉽게 간과할 수 없는 부분이며, 철도가 다른 교통수단에 비해 상대적인 장점으로 내세울 수 있는 안전성을 확보하기 위하여 반드시 차륜과 레일 사이에서 발생하는 상호 작용력을 측정하여 탈선가능성을 평가하여야만 한다.(중략)

• Journal of the Korean Society for Railway
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• v.11 no.3
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• pp.311-316
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• 2008

Ratcheting is a cyclic accumulation of strain under a cyclic loading. It is a kind of mechanisms which generate cracks in rail steels. Though some experimental and numerical study has been performed, modeling of ratcheting is still a challenging problem. In this study, an elastic-plastic constitutive equation with non-linear kinematic hardening equation was applied. Contact stresses in wheel-rail were analyzed. Under the tangential stress of the contact stresses, a cyclic stress-strain relation was obtained by using the model. A constant ratcheting strain per cycle was accumulated.

• Journal of the Korean Society for Railway
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• v.20 no.2
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• pp.234-240
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• 2017

In this study, the influences of rail surface roughness on dynamic wheel-rail forces currently employed in conventional lines were assessed by performing field measurements according to grinding of rail surface roughness. The influence of the grinding effect was evaluated using a previous empirical prediction model for dynamic wheel-rail forces; model includes first-order derivatives of QI (Quality Index) and vehicle velocity. The theoretical dynamic wheel-rail force determined using the previous prediction equation was analyzed using the QI, which decreased due to rail grinding as determined through field measurements. At a constant track support stiffness, an increase in the QI caused an increase in dynamic wheel-rail forces. Further, it can be inferred that the results of dynamic wheel-rail analysis obtained using the measured data, such as the variation of QI due to rail grinding, can be used to predict the peak dynamic forces. Therefore, it is obvious that the optimum amount of rail grinding can be determined by considering the QI, that was regarding an operation characteristics of the target track (vehicle velocity and wheel load).

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.363-364
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• 2006

The important factor to evaluate the running safety of a railway vehicle would be the interaction force between wheel and rail(derailment coefficient), for which is one of important factors to check the running safety of a railway vehicle that may cause a tragic accident. In this paper, when interaction force between wheel and rail happens to wheel-set of tilting vehicles, it analyzes stress distribution and verified safety.

• Journal of KSNVE
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• v.8 no.4
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• pp.616-622
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• 1998

An analytical method has been developed to estimate the dynamic contact force between wheel and rail when trains are running on rail with vertical irregularities. In this method, the effect of Hertzian deformation at the contact point is considered as a linearized spring and the wheel is considered as an sprung mass. The rail is modelled as a discretely-supported Timoshenko beam, and the periodic structure theory was adopted to obtain the driving-point receptance. As an example, the dynamic contact force for a typical wheel/rail system was analysed by the method developed in this research and the dynamic characteristics of the system was also discussed. It is revealed that discretely-supported Timoshenko beam model should be used instead of the previously used continuously-supported model or discretelysupported Euler beam model, for the frequency range above several hundred hertz.

• Computational Structural Engineering
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• v.7 no.2
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• pp.77-87
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• 1994

Vibrational analysis of slab tracks for HSR(High Speed Rail) is performed in order to find dynamic characteristics and to control noise and vibration for the tracks. Wheel-rail interactive force is included in the analysis by modelling the vehicle and track as an unsprung mass and elastically-supported-double-beam respectively, and both are assumed to be connected by the Hertzian spring. From this study, it has been found that vibration in the track and the force transmitted to the infrastructure could be reduced by controlling elasticity, mass and stiffness of the track supporting system appropriately.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.219-223
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• 2004

Korea Railroad Research Institute(KRRI) propelled sensing and measurement techniques development for measure of Lateral Force and Vertical Force With Italy to international cooperation research project for laser technology for measurement of wheel/rail interaction force. In this paper, we compared the laser technology for measurement of wheel/rail interaction force with the existing method. And then, we suggests interaction force measurement system procedure of hereafter.

• Proceedings of the KSR Conference
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• 2003.05a
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• pp.674-678
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• 2003

This research is develop the sensing and measurement technology for measure that wheel/rail interaction force to use laser. Investigated existent laser measurement system, and examined transformation by load that action to wheel for achieve research purpose. A proposed to laser measurement system composition plan to analyze existent method that measure wheel/rail interaction force.