• 한국방재학회 논문집
• /
• 제10권6호
• /
• pp.27-34
• /
• 2010

최근 친환경 운송수단인 고속철도에 대한 관심이 증가하고 있으며, 그에 따른 고속철도 교량이 많이 건설되고 있다. 하지만 기존의 일반 철도 교량에 비해 고속철도 교량은 고속주행하는 열차의 동적 하중에 의한 영향이 증가하게 되므로, 이에 대한 고려가 필요한 실정이다. 따라서 본 연구에서는 고속주행하는 열차의 주행 안정성을 확보하기 위해 고속철도 교량의 구조물-궤도 상호작용 및 동적 안전성을 동시에 고려하여 설계하는 방법을 제안하였고, 제안한 알고리즘의 효율성을 입증하기 위하여 기존의 재래식 설계에 의하여 설계, 시공되어진 단순 5경간 250 m 교량을 대상으로 수치해석을 수행하여 비교하였다. 수치해석 결과, 교량-궤도 상호작용 및 교량-차량 상호작용을 동시에 고려한 최적설계가 기존의 제안된 여러 설계 방법들과 비교했을 때, 최적화의 목적함수로 설정한 생애주기비용이 가장 경제적임을 확인하였다.

• Tribology and Lubricants
• /
• 제31권2호
• /
• pp.42-49
• /
• 2015

Because of the growing need for high-speed transport options such as trains and aircraft, there is increasing demand for technology related to high-speed trains. Among them, braking systems are important in high-speed trains in terms of reliability. Especially, the disk brake system, in use in most high-speed trains, transforms kinetic energy into thermal energy and noise. Therefore, the material properties of both the friction materials and disks are expected to influence the tribological characteristics. In this paper, the tribological characteristics depend on the hardness of the brake disks between the Cu-based sintered metallic friction material and the heat-treated heat-resisting steel disks. A lab-scale dynamometer used to perform braking tests at a variety of braking speeds using dry conditions. The test results revealed that the hardness of the disks affects the friction coefficients, friction stabilities, and wear rates. Thus, the brake system using the heat-resisting steel disk requires proper heat-treatment. These differences are considered to be caused by the change in tribological mechanisms and the generation of an oxide layer on the friction surfaces. The oxide layers on the friction surfaces are confirmed to Fe₂O₃ by x-ray diffraction (XRD) and scanning electron microscope-energy dispersive spectroscopy (SEM-EDS) analysis.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.296-300
• /
• 2007

Roller rigs have been built widely to study and evaluate the dynamic behaviors of railway vehicles, and they have particularly been applied to the development and routine maintenance of high-speed trains. However, there is no roller rig for routine maintenances of high speed train in Korea, although high speed train is running on the lines. Therefore, it is very important issue to check and evaluate the dynamic responses of high speed train after several years of operation. This paper presents a study on the conceptual design and dynamic model to develop the roller rig for the routine maintenances of high speed trains. The roller rig has two independent electronic motor and maximum speed of 350km/h, which can simulate running on straight and curved track. CATIA V5 was used to design the 3D geometrical models and ADAMS was used to verify and analyze the dynamic behaviors of roller rig.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 추계학술대회 논문집
• /
• pp.90-94
• /
• 2007

There are the high-speed train of two types in Korea, KTX and KHST(Korean High Speed Train). The characteristics of interior noise appear differently because the car bodies of the trains are designed with the different materials. In this study, we measure the interior noise for KTX and KHST. The experimental results show that the interior noise of KTX is equal to KHST in open territory and tunnel and interior noise in tunnel with concreted track increase about $3{\sim}4dB(A)$ compared to tunnel with ballasted track. We also know that interior noise level of KHST is higher then KTX in range of high frequency (above 630Hz).

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2005년도 추계학술대회 논문집
• /
• pp.1005-1009
• /
• 2005

The On Board Computer System (ORCS) used for rolling stocks is one of the core equipments in trains, which deals with collecting real-time data of a train to display and record the train's statuses, control the train, and support the driver and maintenance function. Resides, due to high reliability and high speed communication required lately for various electronics including signal1ing devices, train protection system, and multimedia, the necessity of a more robust train communication network is on the lise. This study aims at understanding the technological trend of the current train communication network in order to rapidly cope with the tendency above and providing fundamental data for designing a more advanced communication network for high-speed trains hereafter.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2007년도 춘계학술대회 논문집
• /
• pp.81-84
• /
• 2007

THE THERE HAS BEEN AN INCREASING DEMAND FOR THE NOISE IMPACT ASSESMENT BY HIGH-SPEED TRAINS DUE TO THE EXPANSION OF HIGH-SPEED RAILWAY. THIS PAPER PROVIDES STRATEGIES FOR THE EVALUATION AND THE ASSESSMENT OF THE POTENTIAL NOISE IMPACT RESULTING FROM PROPOSED HIGH-SPEED RAILWAY. FIRSTLY THE NOISE TECHNICAL SPECIFICATIONS FOR THE RAILWAY NOISE HAVE BEEN REVIEWED, AND THE STRATEGIES OF THE NOISE IMPACT ASSESMENT FOR HIGH-SPEED RAILWAY NOISE ABATEMENT HAVE BEEN DESCRIBED.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 2003년도 추계학술대회 논문집(II)
• /
• pp.297-304
• /
• 2003

As the high speed rail to be opened at 2004, the. railroad will dominate over the transportation market in the Seoul-Busan corridor compared to road transport. But, it is obvious that the LOS(level of service) of railroad at 2004 will be worse in the areas that are not served KTX. For the speed-up of conventional line, it is a worldwide trend that tilting trains are served on the conventional railway line. That is the reason serving tilting trains is very efficient to use existing facilities and improve cruise time when capacity is available. In this paper, we suggest 10 routes are replaced with present operating trains(saemaeul, mugunghwa) by the tilting train.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1995년도 창립기념학술대회
• /
• pp.5-29
• /
• 1995

A three-dimensional flow field induced by two trains passing by each other inside a tunnel is studied based on the numerical simulation of the three-dimensional compressible Euler/Navier-Stokes equations formulated in the finite difference approximation. Domain decomposition method with the FSA(fortified solution algorithm) interface scheme is used to treat this moving-body problem. The computed resluts show basic characteristic of the flow field created when two trains passing by each other. History of the pressure distributions and the aerodynamic forces acting on the trains are mailnly discussed. The results indicate that the phenomenon is complicated due to the interaction of the flow induced by two trains. Strong side force occurs between the two trains when the front portion of the opposite train passes by. It fluctuates rapidly and maximum suction force occurs when two trains are aligned side by side. The results also indicate the effectiveness of the present numerical method for moving boundary problems.

• 한국생산제조학회지
• /
• 제23권3호
• /
• pp.310-317
• /
• 2014

The Next-generation High-speed Rail Technology Development Project was started in 2007 by the Korean Government with the aim of developing the core technologies for a high-speed electric multiple unit (EMU) railway system. This is the first attempt to develop a high-speed EMU railway. High-speed EMU trains have superior acceleration and deceleration compared to push-pull high-speed railways such as KTX(Korean Train eXpress). A prototype train was developed and tested on a high-speed line starting in 2012. The new train must maintain running safety during the test. Generally, the international standard (UIC518) is adopted to evaluate the running safety of trains. This method suggests that the test zone must have over 25 sections, and the length of each section must be 500 m. However, it is difficult to implement these test conditions for a real high-speed line. In this study, we analyzed the running safety using several test section lengths (100 m to 500 m) and compared the results. The results of this study will be used to establish a running safety evaluation method for high-speed EMU railways.

• International Journal of Railway
• /
• 제4권3호
• /
• pp.74-79
• /
• 2011

Recent years have witnessed speed up of moving vehicles such as high-speed of trains. Increase in speed entails concomitant increase in turbulent air flow which contributes toward increased aerodynamic noise. The proposed method for aerodynamic noise reduction is based on a biomimetic design of owl feather. The five morphological parameters of the owl feather are extracted from close observation, and simulation cases are constructed by applying design of experiments methodology. Swirling strength for each case is obtained through steady-state CFD analysis, and key morphological parameters that affect the turbulence are identified. Large eddy simulations (LES) are then performed on selected cases to predict the air turbulence. Different cases show varying vortex distributions which are expected to lead to varying aerodynamic noise levels.