• 한국정밀공학회지
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• 제32권7호
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• pp.591-595
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• 2015

The roller rig tester for safety performance evaluation of wheel derailment is a test facility which can give the test load condition to the test wheel, similar to the actual dynamic condition in actual running condition. This study describes the evaluation result on the durability of the resilient wheel equipped with the ring damper and the damping material, and installed in the half part of a full scaled bogie in combination with the primary spring when it rotates under the dynamic condition. The evaluation result on durability of resilient wheel after load test of 2 million cycles shows that the safety of wheel is not affected by the applied load in visual inspection and nondestructive test, however, in the bolt used for fastening the ring damper to the wheel the loosening was found. Accordingly the use of self-locking nut and washer is recommended.

• 대한기계학회논문집A
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• 제33권10호
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• pp.1099-1107
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• 2009

Numerical simulation and experimental study to evaluate the critical speed of the railway bogie according to the tread inclination of wheel profile were conducted using 1/5 scale model. It has been shown that the results of the critical speed analysis for the scale bogie model is very close to the test results using scale bogie model and the critical speed is decreased in proportion to the increase of equivalent conicity of wheel profile. Results of this study show that the scale model could be applied to research area relating to vehicle stability as an alternative to overcome the experimental problems caused by full scale test on the roller rig.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2009년도 춘계학술대회 논문집
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• pp.1550-1556
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• 2009

The sophisticated technologies, ensuring both stability and curving performance, are required for the medium high speed train running on conventional railway line where tangent and curved section mixed together. We can hardly meet the both requirements conflicting each other with the conventional type of bogie. Effective solution is to apply stabilizing mechanism for the bogie design, which increase hunting stability or dynamically critical speed while maintaining curving performance. In this research the numerical analysis by means of multi-body dynamic simulation S/W, experiments by using roller test rig and main line running test have been comprehensively performed for the 200km/h Korean Tilting Train with newly developed stabilizer. The paper proposes the effectiveness of stabilizer and its usefulness based on the results of analyses.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.2600-2608
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• 2011

The dynamic stability of railway vehicle has been one of the important issues in railway safety. The dynamic simulator has been used in the study about the dynamic stability of railway vehicle and wheel/rail interface. Especially, a small scale simulator has been widely used in the fundamental study in the laboratory instead of full scale roller rig which is not cost effective and inconvenient to achieve diverse design parameters. But the technique for the design of the small scale simulator for the fundamental study about the dynamic characteristics of the wheel-rail system and the bogie system has not been well developed in Korea. Therefore, the research about the development of the small scale simulator and the bogie has been conducted. As this paper, To predict the dynamic behavior of railway vehicle, we studied running stability test of 1/5 scaled bogie that similarity laws is applied using small scale derailment simulator. For the operation of the small scale derailment simulator, it is required to investigate the performance and characteristics of the system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying of the test results and understanding of the physical behavior of the dynamic system comprising the small scale bogie and the simulator.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 춘계학술대회 논문집
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• pp.1085-1091
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• 2011

The dynamic stability of railway vehicle has been one of the important issues in railway safety. The dynamic simulator has been used in the study about the dynamic stability of railway vehicle and wheel/rail interface. Especially, a small scale simulator has been widely used in the fundamental study in the laboratory instead of full scale roller rig which is not cost effective and inconvenient to achieve diverse design parameters. But the technique for the design of the small scale simulator for the fundamental study about the dynamic characteristics of the wheel-rail system and the bogie system has not been well developed in Korea. Therefore, the research about the development of the small scale simulator and the bogie has been conducted. This paper presents the design of the small-scaled derailment simulator and the example design case of a small scale bogie. The simulator could be used in the study about the effect of diverse parameters such as attack angle, wheelbase and cant on dynamic behavior of the bogie and the safety parameter such as derailment coefficient and critical speed.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 춘계학술대회논문집
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• pp.951-956
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• 2008

The study is to develop a foundation design for a railway vehicle simulator using a scaled model. Although a scaled simulator is limited to manipulate the dynamics of a full-size railway vehicle, it has been known to have an advantage, since a scaled model could provide the fundamental dynamic behavior within a limited space of a laboratory facility and with a low operation cost while an experiment is conducted. This study is to propose a design strategy for a simulator so that a small scaled roller rig could be fabricated in a laboratory based on the design philosophy. The data obtained from the scale model is also experimentally investigated in conjunction with appropriate non-dimensional analysis so that the output results should be interpreted to the railway vehicle.

• International Journal of Railway
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• 제4권1호
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• pp.5-11
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• 2011

The purpose of the present study is to develop conceptual design of a railway vehicle simulator based on a scaled model. Although the scaled simulator is limited in its ability to manipulate the full dynamics of a full-size railway vehicle, it has been known to have an advantage in that it could provide means of testing the fundamental dynamic behavior within a limited laboratory space and at low operation cost. The present study proposes a design strategy for a simulator so that a small scaled roller rig could be fabricated and operated in laboratory setting based on the design philosophy. The data obtained from experimental testing using a scale model can be used to verify and interpret the dynamic performance of full-scale railway vehicle by applying appropriate non-dimensional analysis.

• 한국철도학회논문집
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• 제15권1호
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• pp.9-16
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• 2012

철도차량의 탈선은 발생 시 대형사고로 이어질 수 있어, 철도차량의 주행안전 확보 문제는 철도운영기관 및 시설기관의 주요 현안 사항이다. 현재 대차의 동적 안정성 특성 시험은 대차 주행시험대라는 시험설비를 이용하여 시험을 하고 있다. 그러나 실물을 대상으로 한 실물규모의 주행시험대상에서의 동특성 시험은 시험 준비와 관련된 시험비용 및 시험소요 시간의 증가, 다양한 시험조건 설정 측면에서 어려움이 있다. 이러한 단점을 극복하고자 시험 편의성 측면에서 축소형 주행시험대를 활용하고 있으나 국내에서는 아직까지 축소대차, 축소트랙 등의 기초적인 수준의 연구가 진행되고 있다. 본 연구에서는 철도차량의 동적 거동을 예측하는 방법으로서 소형탈선시뮬레이터를 이용하여 상사기법이 적용된 1/5 축소대차의 주행안정성 시험에 대한 연구를 수행하였다. 또한, 시험데이터와 해석데이터를 비교·검증하기 위하여 상용해석프로그램을 이용하여 해석모델을 구현하고, 이를 이용하여 도향상에 따른 1/5 축소대차의 동적특성을 확인하였다.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2003년도 추계학술대회 논문집(I)
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• pp.125-130
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• 2003

Korean High Speed Train (KHST) designed to operate at 350km/h has been tested on high speed line in JungBu site since it was developed in 2002. The dynamic performances of railway vehicle are generally stability, safety and ride comfort. The stability performance of KHST was proved that it is stable at 400Km/h through Roller Rig test. The safety and ride comfort need to be predicted the capability of it at 350km/h by the on-line test because KHST is testing at 300km/h up to now. Therefor, in this paper, the safety and ride comfort at 350km/h are predicted the performance using the acceleration results at 300kw/h and these results show that the KHST's dynamic performances are very good. Also, it illustrate the two cases occurred the abnormal vibration of KHST during some on-line tests. The first case is that the variation of vertical acceleration of wheel is analyzed when an abrasion occur on wheel. The second case is that the lateral acceleration of wheel, bogie and body are analyzed when the KHST is unstable at high speed. The occurrences of these special phenomena were due to the some faults of the suspension and braking systems and the faults were improved. In present, it is testing with safety.

• 한국철도학회논문집
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• 제10권3호
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• pp.257-263
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• 2007

The critical speed above which the vehicle become unstable is one of the items that should be verified in the development of a new train. In the case of a high speed tilting train, which requires both higher critical speed and higher curving speed, the critical speed should be more carefully treated because the both requirements are in conflict with each other in the conventional train design. The main purpose of the present work is to estimate the linear and non-linear critical speeds of 200km/h Korean Tilting Train 'Hanbit200' under development. The newly developed self-steering mechanism was attached to the tilting train to ensure that the critical speed falls under the lower yaw stiffness which is needed to secure higher curving performance. The simulation for predicting the critical speed was done by a commercially available vehicle dynamics software. A full scale roller rig test was carried out to validate the numerical results and to verify the effectiveness of the self-steering mechanism.