• International Journal of Naval Architecture and Ocean Engineering
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• v.10 no.3
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• pp.348-359
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• 2018

A series of indoor simulation tests on a large-sized shaking table was performed, which was used to simulate the earthquake ground motion for the pipe-soil interaction system to be tested. The purpose of this study is to examine the dynamic characteristic and seismic response of a length of PVC pipeline lay on a clay seabed under seismic load. The pipeline was fully instrumented to provide strain and acceleration responses in both transverse and in-line. Dynamical modal tests show that corresponding mode shapes vertically and horizontally are basically the same. But the absolute values of the natural frequencies vertically are all higher than those corresponding values in transverse. It turned out that the geometry configuration of riser affects its stiffness. Seismic response of pipeline depends significantly on the waveform, and Peak Ground Acceleration (PGA). As the seismic loading progressed, the strain response was severe around both TDZ and catenary zone. Additionally, strain responses in top and bottom positions were more severe than the result in left or right side of the pipeline in the same section.

• Journal of Ocean Engineering and Technology
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• v.27 no.1
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• pp.59-66
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• 2013

A suction anchor is one of the most popular anchors for deepsea floating systems. An anchor used for catenary mooring is predominantly under a horizontal load. In this study, the behavior of a suction anchor installed in cohesionless soil was investigated when the anchor was mainly subjected to a horizontal load induced by a catenary line. In order to study the behavior of the suction anchor, 3D FEM analysis models were developed and analyzed. Depending on the location of the load (padeye), the ultimate horizontal load was monitored. The distributions of the reaction forces around the anchor induced by the seabed were analyzed using the circumferential stress to understand the behavior of the suction anchor under a horizontal load.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.701-704
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• 2006

The catenaries must guarantee the constant electricity to the trains, so that the safety and the estimate of fatigue degree and the inspection of abrasion degree should be done rapidly. This thesis proposes the system that can manage the performance/failure of the catenaries using the image process as the solution for the weak points of the existing inspection such as the decrease of immediateness and the lack of constancy in the human resources. This study simulates the ALD using VHSV (Virture HSV) which is the unreal HSV images, not getting the real HSV in ages to the image processing technique that repeats the erosion and the expansion of the images as the methods that can monitor the slight/critical defects of the catenaries as dealing with the result of the catenaries inspection images. The final ALD (Abnormal Line Detection) system is designed based on this simulation. I have demonstrated it with the VHSV (Virture HSV) virtual images as the materials of the test and inspected it through testing the defects of the catenaries for the thesis.

• Proceedings of the KSR Conference
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• 2007.05a
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• pp.816-823
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• 2007

Electric car tract plays the role of supply high electric power to the electric car from the substation by using Pantograph of the electric car. It is always exposed to the external atmosphere, which results in quite substantial fluctuations in current and voltage during operation of electric car. This generates possibility of occurrence of accident at all times. Since range of wiring metallic globe installed on the catenary cannot achieve complete electrical contact, accidents are occurring due to circulating current caused by arc caused by incomplete contact due to occurrence of hairline fracture of Pantograph due to pressure or vibration of wiring. Furthermore, rapid increase in the operational current due to increase in the operational frequency of the electric car is causing erosion and short circuit of the metallic globe at the contact points. This study on arc is generated as current transmitted out of the substation courses through power line or wiring metallic globe other than the main circuit as the current is being collected at the electric car through feeder and feeder divergence device. Accordingly, since heat generated by the arc becomes the cause for generation of circulating current due to melting of metal or softening of metal due to increase in temperature accompanying increase in contact resistance, this research shall describe causes and measures against occurrence of circulation current.

• Journal of the Korean Society for Railway
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• v.14 no.3
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• pp.222-227
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• 2011

The dropper supports the contact wire and is attached using various types of dropper clips on the catenary. Droppers are subject to mechanical stress from buckling during the passage of pantographs. In order to investigate failure causes for the high speed line dropper, theoretical analyses and experiments have been carried out. In this paper, mathematical formulas are derived for the pre-sag of the dropper static load. The measured values in the experiment were similar to the theoretical predictions. To analyze the cause on fracture of dropper wire, we have conducted analysis such as SEM(Scanning Electron Microscope) of fractured specimens in the field and new specimens. Finally, we performed measurement for the variation of dynamic load on the dropper when a pantograph moved at 300km/h under the Korean high speed overhead line. If such mechanical load occur repeatedly with every passing pantograph, it is possible that the dropper wire will break due to fatigue. This results will be used for special management of high speed catenary system maintenance and life estimation of dropper.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2998-3006
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• 2011

This paper is about the relations between the electric multiple unit and ESS(Energy Storage system, here after) applying bi-direction Buck-Boost Converter. ESS may be possible to suppress the line voltage drops and the power loading fluctuations and to save the regeneration power lapses. This paper confirm for simulation that ESS reusing regenerative power generated during braking in train. Also, presents the influence of regenerative power variation of train and catenary acceptability for energy saving obtained by applying the ESS to Daejeon Metro line 1.

• Proceedings of the KSR Conference
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• 2004.06a
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• pp.595-601
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• 2004

The pantograph for Korean High Speed Train was developed and had been evaluating by through 'G7-R&D project' for home grown high speed train technology. In this paper, from the point of view in mechanical aspect, comparison study on the current collection characteristics between the KHST pantograph and contact wire in catenary system on the High-Speed Line and Ho-Nam/Kyoung-Bu conventional lines is conducted. A measuring system for the performance and mechanical characteristics of the KHST pantograph is used for this study, which was developed and installed on the Proto-type Korean High Speed Train, and physical characteristics were measured while the KHST runs on the High-Speed Line and conventional lines. Through this study, remarkable variations of characteristics which can affect to a current collection quality of high-speed train are found and analyzed from measured mean contact forces in both tracks.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.671-676
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• 2006

A measurement system was developed in this study. It conducts on-line testing and evaluation of tilting train express(TTX). The measurement system is installed in each train for the performance measurement during the test run. It is composed of software part, hardware part and can measure various signals such as vehicle velocity, catenary voltage, motor temperature. The software controls the hardware of the measurement system, performs the analysis and calculation of measurement data and acts as interface between users and the system hardware. The hardware is consisted of 7 DAMs(Data Acquisition Modules) and 6 monitoring modules.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1381-1383
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• 2000

A multi-train operation simulation software is under development, in this G7 Project for a High Speed Train System, to simulate the running performance, power consumption, signalling and operation. In the first stage, a Train Performance Simulation (TPS) software is introduced in this paper. This is a core module of whole system and gives some parameters of a train, e.g., its position, speed traction and braking power and electric power system state, etc. In this paper, calculation technique was used for voltage drop at the train's positions and major posts along the catenary line. The final program will be used as an evaluation tool for system performance in constructing a new line or introducing a new train system.

• Proceedings of the KSR Conference
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• 2010.06a
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• pp.810-815
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• 2010

Since a long time ago, many railway engineers analyze and discuss the interface between the sub-system of railway, such as a wheel/rail interface, pantograph/catenary interface etc. The verifying of the system interface could help to achive the optimized performance and safety of the railway system considering that the railway system is constructed by various engineerings, such as civil, mechanical, electrical, etc. A rolling stock with distributed drive system, which will be developed by HEMU-400x project, is capable of running on high speed line and conventional line in Korea. To verify the performance of rolling stock, test run will be done with revenue service line. And the test items of the system interface have to be selected to verify a functional compatibility and physical force between rolling stock and infrastructure. In this paper, the authors will indicates the test items to verify system interface. To achive the conclusion, the authors analyze a specification of the development train and the design value of Seoul-Busan high speed line, which will be used for testing of the development train, and also, study the various case of high speed train commissioning.