• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.20 no.5
• /
• pp.598-604
• /
• 2011

In guard rail crashes, the development of guard rail structure to ensure the maintenance of safety for passengers is very important. So, this paper focuses on understanding the possibility of efficient structural development considering crash strength of guard rail through computer simulation using the commercial code, LS-DYNA3D at the initial stage of guard rail development. For this study, guard rail structure was modeled using shell elements to represent major structural members and passenger car was modeled using plate elements of simple shape to do not have the drawing, and impact boundary conditions required by regulation was applied. In order to confirm the validity of the computational results, they were compared with the test results.

• International Journal of Railway
• /
• v.5 no.2
• /
• pp.71-76
• /
• 2012

Recently, axle load, operating speed and traffic density on railroads have had a tendency to increase and thereby cause additional pressure applied on used track. These operating conditions frequently result in service failure due to wear caused by wheel-rail contact and fatigue damage under cyclic loading. Among rail defects, the transverse crack, which has been the most dangerous type of fatigue damages, is developed from the subsurface crack near the rail running face and grows perpendicular to the rail surface. Therefore, it is necessary to investigate systematically the growth behavior of transverse crack for rail steel under mixed mode. In this study, the fatigue crack growth behavior of the transverse crack in rail steel was experimentally investigated under mixed-mode variable amplitude loadings.

• International Journal of Railway
• /
• v.2 no.2
• /
• pp.80-92
• /
• 2009

Successful market adoption of rail freight transport innovations that might offer opportunities for market share increase is the focus of this paper. Firstly, seen from a theoretical point of view, it is not incremental innovations but radical organizational and transformation innovations that are likely to increase the market share of rail freight transport. Secondly, the particular inovations that offer some success potential for market adoption are: dedicated infrastructure, the fixed timetable, locomotive upgrades, and INTERFACE. Thirdly, unfortunately, the opportunities to increase the market share of rail freight transport appear to be limited.

• 제어로봇시스템학회:학술대회논문집
• /
• 2003.10a
• /
• pp.1741-1744
• /
• 2003

This study is a kind of preliminary research in order to propose and suggest the plan of performance improvement for the speed-up through the examination of operational condition on the field for signal system facility on the conventional railway, in order to obtain the elemental technology from the technical development for utilization of high speed train which will be run on the Korea Conventional Line and, finally, in order to propose the specification of signal system using for high speed and the scheme of establishment for the optimal signal system.

• Proceedings of the KSR Conference
• /
• 2001.10a
• /
• pp.534-539
• /
• 2001

This paper presents the critical speed analysis of geogrid-reinforced rail roadbeds on soft soil. A rail roadbed on soft ground must be designed to avoid intolerable stress in the underlying soil and to give sufficient support for the rail system. At high speeds, the deformation of rail systems will gain dynamic amplification, and reach excessive values as a certain speed, here termed critical speed is approached. The elastic Winkler foundation model was used to predict the critical speed of geogrid-reinforced rail roadbeds on soft soil and the model properties were determined by the in-situ cyclic plate load test. Based on the parametric study of elastic beam on Winkler foundation model, the critical speed increase with the increase of the flexural risidity of subgrade EI and the stiffness coefficient of Winkler foundation k. From the in-situ cyclic load tests and analysis of elastic beam on Winkler foundation model, the critical speed increase with increase in number of reinforced layer and non-dimensional value for depth of first geogrid layers and the thickness of reinforced rail roadbed u/d.

• Journal of KSNVE
• /
• v.8 no.4
• /
• pp.616-622
• /
• 1998

An analytical method has been developed to estimate the dynamic contact force between wheel and rail when trains are running on rail with vertical irregularities. In this method, the effect of Hertzian deformation at the contact point is considered as a linearized spring and the wheel is considered as an sprung mass. The rail is modelled as a discretely-supported Timoshenko beam, and the periodic structure theory was adopted to obtain the driving-point receptance. As an example, the dynamic contact force for a typical wheel/rail system was analysed by the method developed in this research and the dynamic characteristics of the system was also discussed. It is revealed that discretely-supported Timoshenko beam model should be used instead of the previously used continuously-supported model or discretelysupported Euler beam model, for the frequency range above several hundred hertz.

• Journal of the Korean Society for Railway
• /
• v.6 no.1
• /
• pp.58-65
• /
• 2003

Wheel/Rail geometric constraint relationships, such as effective conicity and gravitational stiffness, strongly influence the lateral dynamics of railway vehicles. In general, these geometric contact characteristics are nonlinear functions of the wheelset lateral displacement. There is a need to develop a wheel/rail geometric contact simulation program for wheels and rails with arbitrary profiles for the prediction of the dynamic behavior of railway vehicles. An algorithm to simulate any combination of wheels and rails is employed and a GUI for easy analysis is constructed. The simulation program is applied to KTX which will run on both KTX and conventional rails, two rail standards having different rail profiles. The results show that the two rail systems have different geometric contact characteristic

• International Journal of High-Rise Buildings
• /
• v.7 no.2
• /
• pp.95-109
• /
• 2018

Since the concept was first introduced in the 1970s, transit-oriented-development (TOD) has greatly expanded in East Asian cities such as Hong Kong. Rail stations are built together with clusters of residential-commercial towers and government services to form a new style of living - a "rail village." This paper examines the composition, scale, spatial form, organization and operation of several typical rail villages in Hong Kong. The cases range across those planned from the mid-1990s to 2015. Based on the analysis of the rail village composition, the paper derives a development ratio to indicate the density, effectiveness and efficiency of a rail village catchment area. The ratio provides a useful and direct figure for the comparison of different stations, cities and development modes.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
• /
• 2006.10a
• /
• pp.115-120
• /
• 2006

The rail clamp is the device to prevent the crane slips along rails from the wind blast as well as to locate a container crane in the set position in operating mode. In this study we conduct the research for the sliding distance of rail clamp and the proper position of supporter with respect to the wedge angle in the wedge type rail clamp. The sliding distance to display the clamping force of the jaw pad corresponding to the design wind speed criteria is determined by the total displacement of the rail clamp at the roller center and the wedge angle. And the supporter is the device to prevent the overload which is applied on each part of the rail clamp by wind speed increment, because a clamping force is generated by the sliding of the wedge due to the wind. Accordingly the position of the supporter to prevent the overload is determined by analyzing the forces applied to the rail clamp. In order to analyze the sliding distance and the proper position of supporter with respect to the wedge angle as the wind speed is 40m/s, 5-kinds of wedge angles, such as 2, 4, 6, 8, $10^{\circ}$, were adopted as the design parameter.

• Transactions of the Korean Society of Automotive Engineers
• /
• v.24 no.3
• /
• pp.338-344
• /
• 2016

The study is actively being performed to increase fuel injection pressure of common rail system among countermeasures to meet the emission regulation strengthen of the Diesel engine. The common rail fuel injection tube in such ultra high pressure common rail system has the weakest structural characteristics against vibration that is generated by fuel injection pressure and pulsation during engine operation and driving. Thus the extreme durability is required for common rail fuel injection tube, and the drawing process is being magnified as the most important technical fact for strength of seamless pipe that is the raw material of common rail tube. In this respect, we analyzed the characteristic of dimension and stress variation of the ultra high pressure common rail fuel injection tube by variation of Die and Plug angle in drawing process. Based on the analysis, we tried to obtain the raw material strength of common rail fuel injection tube for applying to the ultra high pressure common rail system. As a result, Plug angle is more important than entry angle of Die and we could obtain the target dimension and strength of the ultra high pressure common rail fuel injection tube through optimization of Plug angle.