• Journal of KSNVE
• /
• v.7 no.6
• /
• pp.953-958
• /
• 1997

Corrugation of railway track can be caused by the various dynamic behaviors of traveling wheels and track. In this paper, the coupled vibrations of traveling wheel and railway track are analyzed as the cause of corrugations. To analyze the coupled vibration, the track supported by the sleepers and the traveling wheels are identified to the elastically supported infinite beam and the spring-mass system which runs at constant speed. The Hertzian contact spring is considered between the infinite beam and spring-mass system are calculated. The cause and development of rail corrugation are discussed in the view point of contact force fluctuation affected by the elastic supports and the corrugated surface profile on the track. By the obtained results, the possibilities of resonance are checked between the excitation by the corrugated surface profile and the natural frequency of contact spring-mass system. It may be thought to a development of railway corrugation.

• Journal of the Korean Society for Railway
• /
• v.8 no.4
• /
• pp.379-384
• /
• 2005

To maintain the stability during the operation of railway vehicle, the perfect installation of rail, namely the orbit as well as the performance of the railway vehicle itself is required. The orbit of railway needs the intensity and elasticity that stands the shock and vibration due to the weight of the railway vehicle enough, Also, the driving safety during the operation of vehicle should be guaranteed, comfortable feeling of the passenger should be maintained, and the influence of the noise and vibration to the environs should be minimized. Therefore, it is necessary to develop a program that calculates the change of construction cost according to the selection of railway orbit. This study introduces the orbit design automation program according to the selection of railway orbit, and discuss the principle and the way to use of the program.

• Proceedings of the KIEE Conference
• /
• 2008.09a
• /
• pp.72-75
• /
• 2008

The Electromagnetic Interference(EMI) in railway applications is largely due to doing the power conversion for traction and Auxiliary system on the Highspeed Electric Multiple Unit-400X(HEMU-400X). In order to research on EMI in railway applications, it were included how much the HEMU-400X generates it and it has an effect on the equipments of electric system which resulted from Power Line Disturbance (PLD) phenomenon by the loss of contact during its running. In this study, the dynamic characteristic of a contact wire and pantograph suppling electrical power to high-speed trains are investigated. The analysis of the loss of contact based on Power Simulator program software is performed to develop power line disturbance model suitable for high speed operation. It is confirmed that a contact wire and pantograph model are necessary for studying the dynamic behavior of the pantograph system.

• Journal of KSNVE
• /
• v.11 no.2
• /
• pp.354-364
• /
• 2001

The vibration induced by high speed train running on rail is dealt with as an environmental problem. The train induced vibration is characterized by moving loads at specific frequencies and soil conditions. In fact, it is predicted that the vibration sources are involved the wheel distance, number of cars, speed of operation, drift of rails, structural born vibration, etc. In this paper the characteristics of transferring vibration induced by the high-speed train in operation is discussed. Field measurements was conducted at region from Chungnam Yungj So-jung-myan to Chungbuk Chungwon hyun-do-myun. In the near future. these data will be used as the fundamental data for establishment of the countermeasure for vibrational reduction of high speed train using the results of the field measurements and quantitative prediction of the vibration level

• Proceedings of the KSR Conference
• /
• 2004.06a
• /
• pp.778-782
• /
• 2004

Floating floor structure, which is mainly adopted for reducing interior noise of railway vehicle, is known that it is superior to single wall in respect of sound transmission loss. The dynamic characteristic of the support in the floating floor that is one of the important design variables in floating floor structure can change the sound and vibration insulation properties of it. From excitation test, the dynamic stiffness and loss factor of the support are evaluated. They are used as input parameter for analyzing the sound transmission loss of floating floor. Predicted transmission loss is compared with the prototype-car test results.

• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.488-493
• /
• 2001

CWR technology is generally believed to contribute to the increase of train speed and bring a variety of significant advantages, such as the decrease in track works, noise and vibration as well as the improvement of passenger comfort. In CWR technology, welding is considered to be one of the most important element technologies. Among the various welding methods, thermit welding is the most frequently used one for site welding since the operation is simple and the instruments are light as well as easy to deal with. However, it could cause interference with safety operation of trains since thermit welding points, are essentially made of castings and there are potentialities of defects according to the operation conditions, the environment of the site as well as the dexterity of the worker. This study tries to describe the characteristics of thermit welding, defect-causing factors and defect-detection methods at welding points.

• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.544-549
• /
• 2005

To maintain the stability during the operation of railway vehicle, the perfect installation of rail, namely the orbit as well as the performance of the railway vehicle itself is required. The orbit of railway needs the intensity and elasticity that stands the shock and vibration due to the weight of the railway vehicle enough. Also, the driving safety during the operation of vehicle should be guaranteed, comfortable feeling of the passenger should be maintained, and the influence of the noise and vibration to the environs should be minimized. Therefore, it is necessary to develop a program that calculates the change of construction cost according to the selection of railway orbit. This study introduces the orbit design automation program according to the selection of railway orbit, and discuss the principle and the way to use of the program.

• Proceedings of the KSR Conference
• /
• 2000.11a
• /
• pp.468-475
• /
• 2000

An air spring was accepted for rail vehicle secondary suspension to reduce and absorb tile vibration and the noise. The air spring for the electric railway was developed with domestic technology, which consisted of a cord reinforced rubber bellows, a upper plate, a lower plate and a stopper rubber spring The fatigue test was conducted in laboratory by using servo hydraulic fatigue testing system to verify the durability. And to guarantee the adaptation of this air spring, the ride comfort and the air pressure variation were measured in train test on Boondang line.

• Proceedings of the KSR Conference
• /
• 2007.05a
• /
• pp.964-967
• /
• 2007

Tilting trains are now an established feature of railway operations throughout the world. For intercity traffic, tilt provides operators with increasing speeds, and therefore enhanced competitiveness, on existing routes where insufficient traffic or a lack of funds precludes the construction of a dedicated new high-speed railway. Appling the tilting train, we can expect 30% of speed up on existing lines, but the stability of the electric current would be low because of tilting the train. Also, the spark between the catenary and pantagraph cause environmental problems such as noise, radio wave malfunction. Therefore, the tilting on pantagraph for the power suppling device is very essential for stable electric power supply.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.816-822
• /
• 2010

A comprehensive review for the selection of urban rail vehicle systems that best suit Gimpo railway line is taking place with consideration of the project area characteristics in light of line planning, passenger demand, supply of rolling stock, and railway construction and operation. Various aspects of vehicle systems including passenger demand on concerned lines, regional characteristics, vehicle types, and railway construction and operational settings should be taken into consideration. In addition, request for the introduction of customized vehicle systems reflecting the convenience of transit users such as wide and hospitable inner space, low noise, flexible operation of 2 to 4 car train-set and eye catching slim bridge piers is increasing. A study on alternatives to place an order to opt for optimum rolling stock systems considering line characteristics of Gimpo City's urban railway and future passenger demand while meeting the needs of Gimpo City has been conducted.