• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 추계학술대회 논문집
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• pp.435-442
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• 2004

Tilting train allow the train to pass curve at higher speed without affecting passenger comfort. As the tilting trains run curve track about 30$\%$ higher than non-tilting trains, the centrifugal force and dynamic force will be higher. Therefore it is very important for tilting train to ensure safety against derailment, and to reduce the lateral track forces by applying light-weight design, optimized suspension design and steering mechanism. The 180 km/h Korean Tilting Train(TTX) which is now developing as a part of the Korean National R & D project, was designed and analytically verified to meet these special requirements. This paper describes the analytic study to verify the safety against derailment, especially on the wheel unloading in case of tilting actuation. The severest curve geometry and curving speed was assumed, the tilting control pattern was also assumed as trapezoidal force function applied to tilting bolster and bogie frame. For the comparison, the operation with the speed of tilting train without tilting actuation was numerically simulated and the operation with the balanced speed without tilting actuation was also numerically simulated. Through the numerical simulation of various operating case, we found that derailment quotients, wheel unloading and Q/P was not affected by tilting actuation and that the bogie of TTX was nicely designed to satisfy the safety against the derailment.

• 한국지진공학회논문집
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• 제13권3호
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• pp.29-38
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• 2009

지진 발생시 교량 상판 연결부의 상대변위로 레일에 발생하는 부가응력으로 인한 레일의 좌굴과 파손은 열차의 탈선을 유발할 수 있다. 교량의 지진응답 증가에 영향을 미치는 지반의 탈선취약요소와 교량의 구조적인 요소를 고려하여 고속철도교량 장대레일의 지진응답을 평가하였다. 연약층이 있는 지반, 상하역전형 지반과 같은 지반 탈선취약요소를 고려하기 위해서 지반을 평행층상지반으로 모델링하여 부지효과가 고려된 자유장운동을 구하고 이를 입력지진으로 사용하였다. 교각 높이나 적용 도상을 변화시키면서 구조적 특성이 레일의 지진응답에 미치는 영향을 분석하였다.

• International Journal of Railway
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• 제4권2호
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• pp.50-55
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• 2011

The dynamic stability of railway vehicle has long been one of the important issues in railway safety. The dynamic simulator has been used as a tool for investigating the dynamic stability of railway vehicles and wheel/rail interfaces. In particular, small scale simulators have been widely used in laboratory studies instead of full scale roller rigs which can be quite costly and rather inconvenient for testing out the effect of diverse design parameters. But techniques for design of a small scale simulator for the fundamental study about the dynamic characteristics of the wheel-rail systems and the bogie systems have not been well developed in Korea. Therefore, a research on the development of a small scale simulator for investigating bogie dynamics needs to be undertaken. The present paper investigates design of a small-scaled derailment simulator and the design of a small scale bogie. The simulator developed can be used to investigate the effect of diverse parameters such as attack angle, wheelbase and cant on dynamic behavior of the bogie and key dynamic performance parameters such as derailment coefficient and critical speed.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2011년도 정기총회 및 추계학술대회 논문집
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• pp.1914-1921
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• 2011

When a railway vehicle passes through curves & transitions, the running speed must be improved by proposing the standards on the maximum running possibility speed of each section on conventional line (Dongdaegoo-Namsunghyun) considering derailment safety. In this paper, To improve the maximum running possibility speed of railway vehicle which passes through curves which have high risk of derailment, the track alignment conditions of conventional line (Dongdaegoo-Namsunghyun) that present transition curve length in current railway construction regulations are controlled. We presented elevation way about the section maximum running possibility speed in conventional line by analysis result.

• 한국소음진동공학회논문집
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• 제20권6호
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• pp.537-545
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• 2010

This study presents a method to evaluate overturning safety and derailment safety of korean tilting train using kinematic analysis of four-bar linkage tilting mechanism. The safety is evaluated considering tilting vehicle body CG displacement. The design sensitivity for stable and safe maximum speed is evaluated around current korean tilting train design data. The current design shows minimum center of gravity displacement. Higher speed can be achieved with larger center of gravity displacement.

• Structural Engineering and Mechanics
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• 제49권3호
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• pp.329-353
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• 2014

Increasing usage of tank cars and their intrinsic instability due to sloshing of contents have caused growing maintenance costs as well as more frequent hazards and defects like derailment and fatigue of bogies and axels. Therefore, varieties of passive solutions have been represented to improve dynamical parameters. In this task, assuming 22 degrees of freedom, dynamic analysis of partially filled tank car traveling on a curved track is investigated. In order to consider stochastic geometry of track; irregularities have been derived randomly by Mont Carlo method. More over the fluid tank model with 1 degree of freedom is also presented by equivalent mechanical approach in terms of pendulum. An active suspension system for described car is designed by using linear quadratic optimal control theory to decrease destructive effects of fluid sloshing. Eventually, the performance of the active suspension system has been compared with that of the passive one and a study is carried out on how active suspension may affect the dynamical parameters such as displacements and Nadal's derailment index.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.507-512
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• 2003

The railroad is a means of large transportation which has many latents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail force, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, it is introduced to preprocess the wheelset for measuring wheel/rail force of high speed rail, such as to treat a measuring wheelset, its finite element analysis, adhesion of strain gauges and static toad test, running test result of main line.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2010년도 춘계학술대회 논문집
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• pp.1703-1712
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• 2010

The safety of tilting train running on curved track is, in general, evaluated with a derailment coefficient calculated by the ratio of wheel load and lateral force, Particularly on curve, the wheel load and lateral force on rail may cause trackbed to be deformed, depending on their intensity, and moreover, often result in critical accident such as derailment. This study hence was intended to identify the cause of wheel load and lateral force so as to suggest the allowable wheel load reduction rate, lateral force limit and derailment coefficient, thereby quantitatively evaluating the operational safety of tilting train. This study therefore was aimed to analyze the wheel load and lateral force occurred during tilting train's operation on circular curve in such a way of comparing with traditional trains, by axle and speed, in a bid to eventually evaluate the operational safety of tilting train.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2008년도 춘계학술대회 논문집
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• pp.1518-1523
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• 2008

Train collision and derailment are types of accident with low probability of occurrence, but they could lead to disastrous consequences including loss of lives and properties. The development of the risk assessment model has been called upon to predict and assess the risk for a long time. Nevertheless, the risk assessment model is recently introduced to the railway system in Korea. The classification of the hazardous events and causes is the commencement of the risk assessment model. In previous researches related to the classification, the hazardous events and causes were classified by centering the results. That classification was simple, but might not show the root cause of the hazardous events. This study has classified the train collision and derailment based on the relevant hazardous event including faults of the train related the accidents, and investigates the causes related to the hazardous events. For the risk assessment model, FTA (fault tree analysis) and ETA (event tree analysis) methods are introduced to assess the risk.

• 한국철도학회논문집
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• 제7권4호
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• pp.367-373
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• 2004

The investigation of running stability of the train for curved track is necessary in view of preventing the train from derailment caused by unbalanced forces transferred from the wheel and guaranteeing moderate level of running safety in curve sections. This paper carried out an analysis of running stability of tilting trains in conventional line which the test operation of tilting trains under development are scheduled. For this purpose, the wheel load and lateral pressure to the rail are evaluated. The criteria for the calculated wheel load and derailment coefficient are compared to the design criteria for running stability. It is founded that the running stability of tilting trains for curved track is guaranteed to have sufficient safety and the train speed in curve is governed by the geometric layout of track rather than the criteria for running stability.