• Journal of the Korean Society for Railway
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• v.2 no.2
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• pp.6-12
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• 1999

In this study, the most important suspension characteristics of railway vehicle, such as primary and secondary stiffness, are optimized to maximize ride qualify. Critical speed, secondary suspension stroke oil tangent track and derailment coefficient on the maximum curvature, are selected as the performance constraints. Piecewise linear curving model is used to evaluate derailment coefficient where it is assumed that wheel/rail contacts occurs at tread or at idealized flange. The combined design procedure is used to optimize above design variables at the same time.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.745-750
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• 2004

For the safety of railway, it should be evaluated for the running safety by measuring the derailment coefficient. Although railway has run the fixed and maintained rail, some of railway is derailed. This report shows the results that performed the static load test, wheelset manufacturing for test, main line running test on the basis of the derailment theory and experience. It is executed main line test into more than 80km/h for estimating the curving performance and running safety of Gwangju EMU. As the test results, could confirm the curving performance and running safety of Gwangju EMU from the results of the wheel unloading, lateral force, derailment coefficient etc. Derailment coefficient was less than 0.8, and lateral force allowance limit and wheel load reduction ratio were enough safe.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.243-249
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• 2000

This experimental study is shows speed-up possibility for the conventional railway vehicle. We appraise derailment coefficient then increase the velocity of the kyungbu line, honam line, changhang line, kyungjeon line.

• Proceedings of the KSR Conference
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• 2004.10a
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• pp.228-233
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• 2004

A derailment coefficient of railway vehicle is as one of important element that estimate running safety. Derailment coefficient is ratio of lateral load/vertical load happens in contact point between wheel and rail. Lateral load increases, dangerous of derailment can rise. There are ground and vehicle to measurement method of these derailment coefficient. Method of ground is simple, but when vehicles passes data of a point, there is shortcoming that acquire locally. Curved surface style wheel shape that use so far among vehicle method in this research wishes to be not but describe about static load test of wheel-set for derailment coefficient measurement that have plane plate shape that manufacture separate way and correction result etc. to test.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.109-114
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• 2007

For the safety of railway, it should be evaluated for the running safety by measuring the derailment coefficient. Although railway has run the fixed and maintained rail, some of railway is derailed. This report shows the results that performed the static load test, wheelset manufacturing for test, main line running test on the basis of the derailment theory and experience. It is executed main line test to 120 km/h for estimating the running safety of express train in Incheon International Airport. As the test results, could confirm the curving performance and running safety of Incheon International Airport EMU from the results of the wheel unloading, lateral force, derailment coefficient etc. Derailment coefficient was less than 0.8, and lateral force allowance limit and wheel load reduction ratio were enough safe.

• Proceedings of the KSR Conference
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• 2006.11b
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• pp.56-61
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• 2006

For the safety of railway, it should be evaluated for the running safety by measuring the derailment coefficient. Although railway has run the fixed and maintained rail, some of railway is derailed. This report shows the results that performed the static load test, wheelset manufacturing for test, main line running test on the basis of the derailment theory and experience. It is executed main line test into more than 110km/h for estimating the running safety of Incheon Int'l Airport EMU. As the test results, could confirm the curving performance and running safety of Incheon Int'l Airport EMU from the results of the wheel unloading, lateral force, derailment coefficient etc. Derailment coefficient was less than 0.8, and lateral force allowance limit and wheel load reduction ratio were enough safe.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.743-748
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• 2007

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. Especially, a newly developed vehicle that first runs commercially requires necessarily the measurement and evaluation of derailment coefficient for securing the safety of a vehicle while measuring the derailment coefficient in view of securing running safety could be the more important factor than any other factors. In this paper, examined possibility that can forecast derailment possibility to behavior of only vibration and displacement by measuring vibration acceleration and displacement in vehicles that travel actuality rail track, and compares with data of wheel load/lateral force result.

• Journal of the Korean Society for Railway
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• v.10 no.5
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• pp.492-498
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• 2007

For the running safety assessment of Saemaul train passing through curves, an analysis model for multibody system has been developed. By using this model and ADAMS/Rail, sensitivity analyses depending on the variation of parameters related to the derailment coefficients have been conducted. At low speed, the derailment coefficient and the unload ratio of right wheel showed higher than left wheel, while those of left wheel showed higher than right wheel at high speed. According to decrease of curve radius, the derailment coefficient and the unload ratio were increased. When the length of transition curve was increased, the derailment coefficient was increased but there was no change on the unload ratio. According to the increase of cant, the derailment coefficient and the unload rate were increased.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.683-684
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• 2008

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.481-484
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• 2008

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. Element that analyze derailment coefficient is consisted of wheel load and lateral force. In this paper, studied about method that calculate vertical force(wheel load) by bending load of axle in rolling stocks.