• Proceedings of the KSR Conference
• /
• 2005.05a
• /
• pp.362-368
• /
• 2005

The KTX is now operating to the commercial purpose at Gyeong-Bu high speed railroad and Ho-Nam conventional railroad to be started on April, 2004. The trains were not found any problems at high speed railroad, but at Ho-Nam line were known to be have the few problems due to operating no planed. In this report should be studied for the effects of the lateral forces and wheel bases, brake distances etc., that high speed trains should be considered on curve running at the conventional railroad. The studied contents for operating at the conventional railroad shall be checked for the technical requirements from design stage, and the trains should be supplied and manufactured to car system to have the good running performances.

• Proceedings of the KSR Conference
• /
• 2010.06a
• /
• pp.1464-1469
• /
• 2010

In this paper, the dynamic stability evaluation of special bridge for high speed railway under ground excitation is performed. The mass, damping, stiffness matrices of bridge are derived from the modal frequencies and mode shape vectors which can be obtained by commercial program. And the high speed train is modeled as multi-single d.o.f models for the sake of vehicle-bridge interaction analysis. In the vehicle-bridge interaction analysis, the vertical directional interaction is only considered. As a numerical example, the 3 span Extradosed bridge which is expected to be installed in Ho-Nam high speed railroad is considered. The analysis results show that the example bridge satisfies the criteria of dynamic stability.

• Journal of the Korean Society for Railway
• /
• v.10 no.5
• /
• pp.540-545
• /
• 2007

The tilting train is able to tilt its body towards the center of the turning radius, preventing roll-over of the train as it runs on a curved rail at high-speed. This train, widely accepted for commercial purpose internationally, is very beneficial in that the operating time is shortened without much capital investment to the infrastructure where there are many curved rails. Over several years, the Korea Railroad Research Institute (KRRI) has developed such a train. In this paper, the safety of the Korean tilting train express (TTX) is investigated using a dynamic simulation model. Since proper safety standards have not been established for the TTX, those for the Korean train express (KTX) is employed to analyze the safety and ride comfort of the TTX. This study is useful in predicting the behavior of the TTX and ride comfort, and conforms that designed TTX is stable enough to satisfy the safety standards. It would be useful to recommend proper normal operating speed and determine the maximum safety speed, according to the result. Furthermore, it would be possible to provide basic reference data when analyzing the dynamic effect of the catenary system and the fatigue of the bogie.

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.35 no.7
• /
• pp.827-833
• /
• 2011

In this study, a simulation model to estimate the current-collection performance of a high-speed train was developed by using a commercial finite element analysis software, SAMCEF. A three-dimensional springDdamperDmass model of a pantograph was created, and its reliability was validated by comparing the receptance of the model to that of the actual pantograph. The wave propagation speed of the catenary model was compared with the analytical wave propagation speed of the catenary system presented in the UIC 799 OR standard. The length of the droppers was controlled, and the pre-sag of the contact wire due to gravity was considered. The catenary and the pantograph were connected by using a contact element, and the contact force variation when the pantograph was moved at velocities of 300 km/h and 370 km/h was obtained. The average, standard deviation, maximum, and minimum values of the contact force were analyzed, and the effectiveness of the developed simulation model was examined.

• Proceedings of the KSR Conference
• /
• 2011.05a
• /
• pp.1563-1571
• /
• 2011

In the commercial trains, there are monitors hung on the ceiling which simply display broadcasted contents so a passenger in a cabin has only one choice of passively watching them or not. To lead the application of IT in railway, keep a passenger from tedious journey, or help a passenger having a productive time, an MCS(Multimedia Contents System) was analyzed, designed, and implemented. A passenger can select and use a content from a smart terminal that is attached at the passenger's seat. A smart terminal is one that has its own memory and processor to handle informations and interact with a user. In this paper, the contents, such as train schedule, transfer information, traveling information, e-book, TV, music, and game, that the MCS can provide were introduced. To validate the applicability of the MCS on a next generation high-speed train, a testing environment will be set on a pre-production car and tested. The successful installation of the MCS will boost up the competitive power of the next generation train in the world market.

• Proceedings of the KSR Conference
• /
• 2006.11b
• /
• pp.1270-1275
• /
• 2006

Korean Train Express (KTX) has opened to commercial traffic since 2004 at maximum speed 300km/h, and Korea High-speed Railway (HSR-350x) was developed by Korean government, several institutes, and related companies. HSR-350x is now being investigated its performance and tested at the high speed line. In 2004 December, HSR-350x was run over 350km/h and proved its running performance. In vehicle system, the faster the vehicle runs, the more vibration increases. To improve the riding comfort of high-speed trains, it needs to devise the vibration absorber. In this paper, we propose the installation of the semi-active damper to the power car of HSR 350x and present the specification and the damping characteristics.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 1998.04a
• /
• pp.97-107
• /
• 1998

Three different kinds of brake discs including two coated brake discs and one steel disc were tested under the same experimental conditions on a reduced scale braking test bench. Braking test bench was specially designed to analyse thermo-mechanical and frictional behaviors of two sizes of brake discs in stop and hold braking modes. And Plasma spray coating technique was used to coat ceramic powder on the discs. In the test four commercial brake pads were coupled with discs. Ceramic coated discs had shown good stability in friction coefficient at high speed and high energy braking conditions. But they caused large pad mass wear loss compared with the steel disc. It was shown that thermal barrier effect in ceramic coated discs adjusted the thermal partition between pad and disc. For a steel disc, it had shown fluctuating friction coefficient at high speed but a fittie pad mass wear loss compared with ceramic coated discs.

• Tribology and Lubricants
• /
• v.23 no.6
• /
• pp.266-271
• /
• 2007

The brake performance of sintered friction materials for the high speed train was studied. In this study, newly developed sintered materials based on copper were compared with the commercial products for high speed trains. They were tested on a 1/5 scale dynamometer using low carbon steel disks. Effectiveness, fade, and recovery tests were carried out to examine friction performance and the change of disk thickness variation (DTV) during brake applications and noise propensity were also evaluated. Results showed that the two sintered friction materials exhibit similar friction coefficients and braking performance, whereas the newly developed friction material was superior in terms of DTV generation and noise propensity to the commercial friction material. The improvement of the newly developed friction material was attributed to the high graphite content which reduced the stick-slip phenomena and prevented uneven disk wear by producing friction films on the counter disk.

• Journal of the Korean Society for Railway
• /
• v.16 no.4
• /
• pp.305-310
• /
• 2013

In general, it is difficult to measure dynamic responses of a bridge with stepwise increasing speed of a train during commercial service on a high speed railroad. However, before opening the 2nd stage of the Gyeongbu high speed railroad, there was an opportunity for field tests and measurements of the bridge with stepwise increasing speed(from 170km/ h to 315km/h). The measured responses were compared with the results of a developed bridge/train interaction analysis. Although good agreement was found throughout almost the entire range of speeds, relatively large differences were found in the vicinity of the critical speed at which resonance behavior of the bridge occurs. To investigate the cause of this, reanalyses are performed with re-estimated damping ratios from field tests.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.25 no.1
• /
• pp.7-13
• /
• 2016

With the increasing running speed of trains, new railway lines in metropolitan areas, and the rising demand for green transportations, the number of underground and tunnel sections are constantly becoming larger, and installations of overhead rigid conductor systems are becoming wider. However, domestic commercial products for overhead rigid conductors are limited to 120 km/h train speeds. In this study, to develop a high-speed (250 km/h) overhead rigid conductor, R-Bar (Rigid Bar), the electrical and mechanical stability was enhanced through the improvement of the cross sectional shape of the R-Bar; the transition structure was also designed for flexibility and natural frequency isolation. In addition, the evaluation of contact forces between a pantograph and the overhead rigid conductor system for 250 km/h train speeds was performed using dynamic analysis.