• International Journal of Railway
• /
• v.6 no.4
• /
• pp.160-168
• /
• 2013

A spiral lattice girder-reinforced Bi-block sleeper which has enhanced durability against increasingly growing impact force and vibration by wheel load and improved structural performance while train runs at 350km/h high speed is hereby proposed. The section of a spiral lattice girder has stable and superior structural performance thanks to its confinement effect. To compare and analyze the structural performance of spiral lattice girder-reinforced bi-block sleeper, strain and stress distribution were evaluated after applying same load condition as existing triangular lattice girder-reinforced biblock sleeper, and to compare the structural performance of triangular lattice girder and spiral lattice girder, structural analysis of lattice girder was performed separately. As a result, a spiral lattice girder proved to have had superior structural characteristics to bi-block sleeper, and furthermore as a result of evaluating the fastener interface and constructibility with shape-improved lattice girder, no interference with existing railroad structure was found and in terms of cost efficiency, a spiral lattice girder appeared to be superior to existing lattice girder.

• International Journal of Railway
• /
• v.5 no.3
• /
• pp.129-134
• /
• 2012

Contact fatigue damages on the rail surface, such as head checks and squats are a growing problem. The fatigue cracks forming on the contact surface grow according to load and lubricating conditions and may end up breaking the rail. Rail fracture can be avoided by preventing the cracks from reaching the critical length. Therefore, the crack growth rate needs to be estimated precisely according to the conditions of the track and load to develop a maintenance plan against rail damages. Therefore, it is important to understand the mechanism of cracks initiation and growth on a rail due to repetitive rolling contact. In this study, we have investigated the crack growth behavior on the rail surface by using the twin-disc tests and the finite element analysis.

• The Transactions of The Korean Institute of Electrical Engineers
• /
• v.62 no.6
• /
• pp.886-890
• /
• 2013

Uplift of contact wire and dynamic characteristics between pantograph and contact wire are key interaction performance of OCS (Overhead Catenary System). These two evaluation items are the approval criteria for the performance between OCS and pantograph. A telemetry system or DAQ (Data Acquisition) System based on wireless communication make it monitor a dynamic behavior which is measured directly in a 25 kv like parts. While permissible working time is too short time to install is too long. In this paper, it is described that optimization the telemetry measurement system for OCS and increasing accuracy, easy adaptation, and faster handling can be also achieved through the study.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.17 no.1
• /
• pp.119-125
• /
• 2016

This study examined the running dynamic characteristics of a hybrid type wheel-rail high speed train, in which the propulsion method of maglev is applied. A wheel-rail high speed train propelled by a superconducting linear synchronous motor (SC-LSM) is expected to be superior to a maglev train regarding economical and interoperable aspects, still having powerful thrust force as maglev. In this paper, regarding the two methods of applying the SC-LSM to an existing wheel-rail train, to investigate the influences of SC-LSM propulsion on the dynamic characteristics of wheel-rail high speed train, the dynamic model of train including interaction between the rotor and stator of SC-LSM is established. Through the simulation using the model, the influence of the interaction between the rotor and stator of SC-LSM on stability, ride comfort and the effect of guideway irregularity are investigated.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.7
• /
• pp.673-678
• /
• 2013

Driving gear units can be affected by various problems, including those associated with external or internal defects in the bearing, problems with the lubricant oil, high-loading of the railway, and frequent impacts generated by rail joints. Temperature monitoring is a basic method in diagnosing abnormal conditions in the reduction gear and other components. This paper describes a new wireless monitoring system for the temperature diagnosis of abnormal conditions of the reduction gear. Integrated circuit (IC)-type temperature sensors were installed in the reduction gear box of a high-speed railway car. The temperature data from the reduction gear were acquired and analyzed in situ during high-speed rail operation. Analysis of these data was used to alert the driver and/or maintenance personnel when problems occurred.

• Journal of the Korea Safety Management & Science
• /
• v.16 no.2
• /
• pp.1-9
• /
• 2014

This study tried to propose plan to prevent human error of railroad driver among human error of railroad worker which takes great share in railroad accident. For this, in order to maintain correlation between the accident actually occurred after the opening of high-speed railroad and experience of accident that did not happened, survey on respondent was analyzed by conducting survey on KTX captain who is working in driving work of high-speed railroad, and instruction management team manager who manages KTX captain and captain. This thesis classified the factors by human factor, job factor, environment factor, organization factor, and established human error management model by comparing and analyzing how each factors have spatial interrelations with a railroad accident. The purpose of this study is to contribute to make safe railroad, and reliable railroad by preventing human error accident by minimizing human error of high-speed railroad drivers, and improving driving workers to cope accurately and fast with irregularities through various institutional improvement, improvement of driving facilities, improvement of operating room environment, and improvement of education system.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2000.11a
• /
• pp.518-523
• /
• 2000

As the delay of the Kyungbu High Speed Railroad, HST should use conventional line through Daegoo to Pusan until the new railroad build. High speed railroad noise is one of the main causes of environmental impact. Whenever HST on conventional railroad line is planned or a housing project near an existing railroad is proposed, an estimate of the relevant noise levels is usually required. For this, it is necessary to Quantify those parameters that affect the railroad noise. This paper deals with an estimation of high speed railroad noise on conventional line.

• Journal of Mechanical Science and Technology
• /
• v.20 no.10
• /
• pp.1548-1556
• /
• 2006

Appropriate contact force is required for the pantograph on the high speed train to collect current from the catenery system without separation. However, at high speed, large aerodynamic lifting force is generated by the contact plate and the body of pantograph, which may cause wear of the contact wire. In this study, to confirm the interface performance of the pantograph on Korea High Speed Train, a method to measure the contact force of the pantograph was proposed and the related measuring system was developed. The forces acting on the pantograph were clarified and a practical procedure to estimate the forces was proposed. A special device was invented and applied to measure the aerodynamic lifting force. Measured contact forces were displayed by the developed system and evaluated based on the criteria.

• 제어로봇시스템학회:학술대회논문집
• /
• 2005.06a
• /
• pp.1374-1378
• /
• 2005

Appropriate upward force is crucial for the pantograph on high speed train to collect current from the catenery system without separation. However, at high speed, large aerodynamic lifting force is generated by the contact plate and the arms of pantograph, which may cause wear of the contact wire. In this study, to confirm the interface performance of the pantograph on Korea High Speed Train, a method to measure the contact force of the pantograph was proposed and the related measurement system was developed. The forces acting on the pantograph were clarified and a procedure to calculate the aerodynamic lifting force was proposed. A special device was invented and applied to measure the lifting force. Measured contact forces were displayed by the developed system and evaluated according to the criteria. Countermeasures were also taken to reduce the contact force based on the results.

• Journal of the Korean Society for Precision Engineering
• /
• v.30 no.7
• /
• pp.694-701
• /
• 2013

The gear-reduction units of Korean high-speed trains consist of a motor reduction unit, an axle gear box reduction unit, and a tripod joint shaft. A reduction gear unit is a gearbox used to reduce the rotational speed of the input shaft to a slower rotational speed on the output shaft. This reduction in output speed helps to increase torque. Defective reduction gear units in high-speed trains are caused by damage to the gear or by gear fatigue. To diagnose potential problems, it is important to know the vibration characteristics of the reduction gear units. In this study, we analyzed the vibration characteristics of reduction gears under various conditions. The test setup included a full-scale test rig to evaluate reduction gear under both normal and extreme operating conditions.