• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1803-1806
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• 2008

Various efforts of reducing the green house gas in the whole industrial fields including railway industry have been implemented. Tilting train is the key example because it can run more faster on the existing rail than others due to its composite body. The system has an advantage of light weight but also a task to solve, recycling of composite material. To recycle the CFRP(Carbon Fiber Reinforced Plastic), there are two typical methods; chemical and thermal method. In this study, more environmentally friendly recycling method was recommended through the environmental function through comparing both recycling methods.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.5
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• pp.19-26
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• 2014

Concrete guide rail and median barrier are an attached RC member, however they are vulnerable to cracking due to slip form construction and large surface of member. In this study, causes and pattern of cracking are analyzed through assessment and NDT (Non-Destructive Technique) evaluation for concrete guide rail and median barrier on highway structure. For this work, analysis on drying shrinkage and hydration heat are performed considering installation period, and plastic shrinkage is also analyzed considering their environmental conditions. From the evaluation, plastic settlement around steel location, drying/ plastic shrinkage, and aggregate segregation are inferred to be the main causes of cracking in the structures. The crack causes and patterns are schematized and techniques of crack-control are suggested. Furthermore concrete guide rail/ median barrier in the bridge on the sea are vulnerable to cracking at early age so that special attentions should be paid at the stages of material selection and construction.

• Journal of the Korea Convergence Society
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• v.10 no.8
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• pp.145-151
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• 2019

In this study, the effects were analyzed by applying the vibration absorption liner into the guide rail bracket as a part of method to reduce the vibration and noise on the high-rise apartment. As the result of vibration absorption liner performance, it was checked that the level of vibration and noise was reduced around 65.49% in the car side and around 90.05% in the counterweight side. Therefore, the vibration absorption effect by the vibration absorption liner of elevator guide rail bracket became fairly good. In case of the vibration absorption liner application, there was an effect on the reduction of 7.26 to 22.22% at hoistway section area, 3,840,000 to 9,780000 KRW at the cost of material and installation by comparing with the damping beam application. Also, in case of the vibration absorption liner application with light weight instead of damping beam with heavy weight, it was thought to become significant effect at preventing the safety from the accidents on installation site.

• Proceedings of the Korean Powder Metallurgy Institute Conference
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• 2006.09b
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• pp.1305-1306
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• 2006

A new material was developed to achieve improvement of heat durability, improvement of wear resistance, stability of friction coefficient and reduction in aggression to counterpart, because it is difficult to maintain braking properties by using currently available materials in the train wagons used for high-speed transportation. As a result, the new material showed a stable wear resistance even in the speed range of 350km/h, where improvement was also confirmed in reduction of aggression to counterpart material by more than approximately 10%. This development was adopted for the brake lining in the Taiwan High Speed Rail project.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.60 no.3
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• pp.552-559
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• 2011

There is a method for offering continuous information by AF track circuits. Magnetic fields are formed by current through rails in the AF track circuit systems. So, the continuous information is received by the magnetic fields on a on-board antenna. Coating materials of spray on rails are researched to decrease defects such as head check, shelling, corrugation, squats and so on in Germany. Currently, a coating method of rail construction is proposed by using the ceramics in Korea. When deciding physical characteristic of the coating material of spray, researches are required about variation of flux density and resistivity by using the coating material of spray. In case that the flux density is much lower than existing value, the information for train control is not transmitted to the on-board antenna. In this paper, inductance on rails is calculated and a model is presented about variation of the magnetic field intensity and resistivity in the AF track circuit. Standard permeability of the coating material of spray is proposed. Also, standard resistivity of the coating material of spray is presented by analyzing short current.

• Proceedings of the KSR Conference
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• 2000.11a
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• pp.311-318
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• 2000

In this paper, the process of development of resilient sleepers, which improves the train safety, passenger comport and reduces the noise and vibration, is discussed. To determine the required material properties of elastic pad, static and dynamic simulations are performed and is applied in manufacturing. From the experiment results, it is investigated that the displacement is less for sleeper with elastic pad than that in ordinary PC form. The rate of displacement is also shown In be less for the sleeper with elastic pad. These results indicate that the elastic pad can reduce possibility of rail-corrugations and thus resulting in the reduction of maintenance costs.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.603-608
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• 2002

Sound absorbing materials are applied to the exposed surfaces of curved subway tunnel for the reduction of curving noise level. Before the treatment, acoustical engineering simulation is performed to predict the noise level reduction for different kinds and amounts of absorbing material. The principle of geometrical acoustics is utilized to Peform the simulation efficiently and accurately. The noise levels of the inside and outside of running car body are measured to find the noise level reduction. The average noise level reduction of 8 ㏈ has been attained. It has been shown that the simulated results are comparable to the measured ones.

• Journal of the Korean Society of Safety
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• v.18 no.2
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• pp.132-138
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• 2003

The use of long rails in high-speed railway bridges causes additional stresses due to nonlinear behaviours between the rail and bridge decks in the neighbourhood of the deck joints. In the seismic response analysis of high-speed railway bridges, since structural response is highly sensitive to properties of the ground motion, spatial variation of the ground excitation affects responses of the bridges, which in turn affect stresses in the rails. In addition, it is shown that high-speed trains need very long distances to stop when braking under seismic occurrence corresponding to operational earthquake performance level so that verification of the safe stoppage of the train is also required. In view of such additional stresses due to long rails, sensibility of structural response to the properties of the ground motion and braking distance needed by the train to stop safely, this paper proposes and establishes a time domain nonlinear dynamic analysis method that accounts for braking loads, spatial variation of the ground motion and material nonlinearities of rails to analyze long rail stresses in high-speed railway bridges subjected to seismic event. The accuracy of the proposed method is demonstrated through an application on a typical site of the Korean high-speed railway.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.6 no.3
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• pp.75-86
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• 1986

The welded joint of the rail of railroad had shown the complicated behaviour of fatigue crack growth due to the effect of low toughness, residual stress, welding stress and strain etc. resulting from welding. Also, the welding connection has been necessary as making longer the rail, thus fatique fracture has often occurred at welded joints. From above, in this paper, faigue test was done at base metal, gas pressure and thermit welded joints to give the basic data to construct S-N diagrams. From this, it was known that the base metal was better than welded joint and gas pressure better than thermit welded joints in the resistance against the behaviour of fatigue crack growth. And it was also found that it is very dangerous to control fracture only by the method of material mechanics.

• Journal of the Korean Society for Railway
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• v.11 no.4
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• pp.424-432
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• 2008

This paper presents theoretical explanations about the spill-over effects of domestic production of light rail transit and empirically investigates its effects on output, value-added and employment in the Korean economy. We distinguish net gains of domestic production from gross effects that bring about whether localized or imported cars are used. The input-output analysis is employed to fully capture the interaction among various industries involved. The empirical results reveal that net gains of domestic production such as import substitution, improvement of trade balances, and increase in output, value-added and employment are enormous. The cost reduction in construction, E&M systems, cars, management, and tariff and transportation is also significant.