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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean society for railway
Journal Basic Information
Journal DOI :
Korean Society for Railway
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Volume & Issues
Volume 6, Issue 4 - Dec 2003
Volume 6, Issue 3 - Sep 2003
Volume 6, Issue 2 - Jun 2003
Volume 6, Issue 1 - Mar 2003
Selecting the target year
Estimation of critical speed and running performance for swing motion bogie of railway freight car
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 215~220
In this paper the dynamic characteristics of a Swing Motion Bogie, such as a critical speed and a carbody vibration, are investigated in reply to the request of the Meridian Rail Corporation in the United States. Also described are experimental results of the maximum speed, the derailment coefficient, the lateral force, the vertical force, the vibration acceleration and steady state lateral acceleration measured from main line tests.
Design of the Multi-Discipline Simulator for the Urban Rail Transit with Object-Based Concept
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 221~231
Most rail system related simulators currently used are designed to simulate only one discipline system. This obviously assumes the other discipline systems are running regularly not being affected by the system being simulated. In this paper a multi discipline simulator is proposed and its design concept is presented. A multi discipline simulator is the simulator in which major subsystems with different technical discipline are simulated simultaneously. The advantage of the simulator is in that it makes it possible to analyze the systems behavior while other discipline system vary. With this we can identify the possible multi-discipline problems and even find their solutions. A proto type simulator has been developed using object oriented programming. Object concept was judged best suitable to model the various multi-discipline self-controlling railway subsystems. It was applied to the target system, which is under development by the Korea Railroad Research Institute. The test results shows it is very useful in designn verification. It could also be a good tool in research and development work to improve the system.
A Study on the calibration of health monitoring system installed in rail infrastructures
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 232~238
A health monitoring system becomes a very useful tool to obtain information on long term behavior of the important railway structures such as very long span and special type bridges. It can be also used to give a warning signal to the maintenance engineer when the structure shows abnormal behavior. However, due to long term use and temperature changes, the health monitoring system needs to be calibrated periodically. In this study, calibration and gauge factor readjustment process made for the health monitoring system installed in the railroad bridges and tunnel are reviewed and a few findings are updated. Future work will be concentrated on the long-term analysis of the measurement data and on the database structures so that the assessment of the structure is possible
Evaluation of Track Impact Factor in the Conventional Line
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 239~245
In this paper, the track impact factor of conventional line was evaluated using the data for wheel load measured in field and the properties of current operating trains. The equation for track impact factor was presented through the statistical analysis of variational ratio in wheel load and compared with other design equations in domestic and foreign countries. A review on the safety of track system in conventional line was made from the relationship between the velocity and the corresponding impact factor. It was found that the impact factor from the proposed equation is a little less than the values from the equations adopted in both AREA and domestic railway, while it is same as the equation for continuous welded rail(CWR) in Japan. Therefore it could be said that the track satisfies a criteria for dynamic load caused by the train and the corresponding level of safety is guaranteed for dynamic load of the train
Allowable Speed of Tilting Car in the Conventional Line
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 246~251
A quantitative analysis on the amounts of cant and lateral displacement of gravitational center due to the introduction of high-speed tilting car was carried out, based on the current alignment of the conventional line. In addition, the maximum allowable speed in curve and the level of improvement in maximum speed of tilting car were evaluated through the comparison with the maximum speed of locomotive. It was found that the tilting car produces an equivalent amount of cant, which corresponds to 47.5 % of current actual cant. This effect could be explained by the fact that 1.34 m, which is the height of gravitational center of tilting car from the rail level, is much lower than that of locomotive and thus guarantees much higher level of safety in curve. The equivalent amount of cant due to the lateral displacement of gravitational center followed by tilting in curve was 2.4 mm. It was small but not enough to be neglected and must be included in calculating the maximum speed in curve. It could be concluded that the 15 % speed-up of the conventional line is reasonable under the current condition of alignment.
Advanced Railway Vehicle Technology using Smart Materials
Kim, Jae-Hwan ; Kang, Bu-Byoung ; Kim, Kyeong-Jin ; Chung, Heung-Chai ; Choi, Sung-Kyu ;
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 252~256
Smart materials can adapt to changes of environment like living organs in nature such that they can maximize the performance and minimize the maintenance expense of engineering systems. Such materials have been paid attention ten years ago and applied in the area of industry, aerospace, transportation and civil structures. This paper summarizes smart material technology and shows some application examples in railway vehicles. Also, its future of smart material technology in railway vehicle technology is envisaged based on its possibility and practical aspect.
Anti-Slip Control by Adhesion Effort Estimation of Railway Vehicle
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 257~264
In electric motor coaches, the rolling stocks move by the adhesive effort between rail and driving wheel. Generally, the adhesive effort is defined by the function of both the weight of electric motor coach and the adhesive effort between rails and driving wheel. The characteristics of adhesive effort is strongly affected by the conditions between rails and driving wheel. When the adhesive effort decreases suddenly, the electric motor coach has slip phenomena. This paper proposes a re-adhesion control algorithm which uses the maximum adhesive effort by instantaneous estimation of adhesion force using load torque disturbance observer. Based on this estimated adhesive effort, the re-adhesion control is performed to obtain the maximum transfer of the tractive effort.
Program Development for the Determination of Equivalent Load for Accelerated Fatigue Testing and the Estimation of Fatigue Life
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 265~272
The computer program for the accelerated life testing technique of a machine part under the service conditions is developed under the GUI environment so that the user can easily obtain the results by selecting the program module. Also, the theoretical backgrounds for the computer program and the procedures of the accelerated testing method are introduced by testing the specimens made of the stainless steel 316L under the high temperature and random loading. The reliability of the program is discussed by the experimental results of the fatigue life, age degradation and accelerated testing conditions.
A Study on Structural Analysis of An Aluminum Bodyshell with A Modular Front End Made of Composite Materials
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 273~278
In this study, an aluminum bodyshell with a modular front end made of composite materials is numerically evaluated applying the standard specifications for the urban EMU (Electric Multiple Unit) train. Structural analyses under compressive load, torsional load and free vibration satisfy the standard specifications, but analysis under normal load doesn't. By the way, the aluminum bodyshell of the car except the modular front end is almost same to that of the Korean standard EMU, which satisfy the standard specifications. It is presumed that the stiffness of the modular front end made of composite materials has some influence on the strength of the aluminum bodyshell.
Simulation-based Parametric Study of the Current Collection System of High Speed Trains
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 279~285
In an electric traction system in which power is supplied from a catenary via a pantograph, the mechanical design of the catenary and pantograph is clearly of importance in relation to the problem of current collection at high speed. A computer-simulation technique is used to study the effects of changing parameters of pantograph and catenary on the quality of current collection at high speed. The current collection system is evaluated on the basis of the contact-force variations and displacement responses of the pantograph and contact wire. This study shows that current-collection quality is determined primarily by the overhead line parameters rather than by the pantograph. The results can be applied to optimize the design of current-collection systems.
Analysis and Evaluation of Body Vibration Characteristics for Korean High Speed Train through On-line Test
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 286~293
The prototype of Korean high speed train (HSR350), composed of two power cars, two motorized cars and three trailer cars, has been designed, fabricated and tested. In this paper, the body vibration has been reviewed from the viewpoint of the vehicle's safety and the vibration limits for components and sub-assemblies mounted on the car-body using by the experimental method. And, the dynamic characteristics, such as jerk, natural mode and kinematic mode, have been reviewed. The KHST has been run to 300 km/h in the KTX line and the results of on-line test show that it has no problems in the vehicle's safety and the vibration limits. And the characteristics of body vibrations has been predicted at 350 km/h by fitting curve about the measured acceleration signals.
Parametric Study of a Bogie Tilting Mechanism
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 294~299
Using a conventional railway, a tilting train was applied as a means of improving vehicle speed during curve negotiation without any modification of infrastructure. As a study for the optimum design of the tilting mechanism of a tilting vehicle, the kinematics sensitivity of the tilting mechanism was analyzed. Using the geometric relationship of the linkage-type tilting mechanism, the relationship of the parameters and the performance index was defined using nonlinear algebraic equations. With the defined relation, the effect of change in the parameters on the performance was analyzed. The analysis result can be used in the optimum design of a tilting mechanism that considers the track environment, vehicle and operational condition in which the tilting vehicle is applied.
Dynamic Analysis of a Bogie Tilting Mechanism
Journal of the Korean society for railway, volume 6, issue 4, 2003, Pages 300~307
Using a conventional railway, a tilting train was applied as a means of improving vehicle speed curve negotiation without any modification of infrastructure. In order to achieve the optimal car-body position control through the tilting mechanism, a dynamics analysis was required after the kinematics analysis of the tilting mechanism. For this, the geometric relationship of the linkage-type tilting mechanism was defined. Then, the equations of motion for the half car-body were derived. With the derived equations, the effect of the parameter change on performance was analyzed. The analysis result can be used in the optimum design of a tilting mechanism that considers the track environment, vehicle and operational conditions in which the tilting vehicle is applied.