• Journal of Welding and Joining
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• v.23 no.1
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• pp.35-40
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• 2005

In this paper, static and fatigue load tests for the specimens, components and carbody were carried out to investigate the strength of welded joints in aluminum rolling stock. Tensile test results showed that the static strength of welded joint for the heat-treated alloy is reduced significantly and fatigue strength data are scattered by the welding imperfections. Component and whole carbody fatigue test results showed agreements with the design fatigue strength standards for specimens of the same joint detail. Test results revealed that full penetration welding and strict management of welding procedure are crucial for securing the strength of welded joint in aluminum carbody.

• Proceedings of the KWS Conference
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• 2004.05a
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• pp.290-292
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• 2004

In this paper, static and fatigue load tests for the specimens, components and carbody were carried out to investigate the strength of welded joints in aluminum rolling stock. Tensile load test results showed that the static strength of welded joint for heat-treated alloys is reduced significantly and fatigue strengths are scattered by the welding imperfections. Component and whole carbody fatigue test results showed agreements with the design fatigue strength standards for specimens of same joint detail. Test results revealed that full penetration welding and strict management of welding procedure are crucial for securing strength of welded joint in aluminum carbody.

• Proceedings of the KSR Conference
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• 1998.11a
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• pp.489-496
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• 1998

Although the surface of aluminum alloy has good corrosion resistance property, the surface of the aluminum rolling stock should be painted for good appearance and protection of the body. For better painting of the aluminum carbody, the surface must also be well pretreated. In this paper, painting process of the aluminum rolling stock is described and the test results of the painted surface is presented. As accumulated data concerning to the painting technology for the aluminum rolling stocks are absent in our country, the presented test results will be helpful for mass production of aluminum rolling stocks in the near future.

• Journal of the Korean Society for Railway
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• v.5 no.3
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• pp.181-186
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• 2002

Aluminum rolling stocks have been developed for six years in Korea and commercial trainsets are being constructed by the carbuilder. Aluminum alloys are sensitive to various imperfections. In this paper, damages and failures of the aluminum carbody taking place during the process of development are investigated and accumulated data are released. Also, remedies for the failures are suggested and design changes are introduced. It is expected that all informations can contribute to construction of reliable and safe aluminum rolling stocks.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.364-369
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• 2002

The purpose of this paper is to introduce the concept design and the structural strength of the double-deck rolling stock vehicle. Aluminum is very useful material for the carbody structure due to its characteristic of light weight. Large alumillum extrusion profiles(panels) have toe of merits such as easy production of complicated shapes, reduction of welding and cutting lines, and cutting down the labor cost. AED type is being applied to the standard EMUs and the EMUs Kwangju subway in Korea. Light material recommended the double-deck rolling stock vehicle because the center of gravity of the train is higher and its weight is heavier than those of the normal vehicle. So we applied the technology of the large aluminum extrusion profiles(panels) to the double-deck vehicle. We performed the structural strength analysis and examined its safety.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2012.05a
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• pp.1023-1024
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• 2012

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.20 no.5
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• pp.477-485
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• 2010

In this study, we suggested several approaches to evaluate the collision acceleration of a carbody under the article 16 of the Korean rolling stock safety regulations. There are various methods to evaluate the rigid body accelerations such as the displacement comparison method by double integration of filtered acceleration data, the velocity comparison method by direct integration of filtered acceleration data, and the analysis method of a velocity-time curve. We compared these methods one another using the 1D dynamic simulation model of Korean high-speed EMU composed of nonlinear springs or bars, dampers, and masses. From the simulation results, the velocity-time curve analysis method and the displacement comparison method are recommended to filter high frequency oscillations and evaluate the maximum and average accelerations of a carbody after a train collision.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.2040-2045
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• 2008

The priority of Crashworthiness concept for rolling stock is progressively increasing to reduce the damage of drivers and passengers as well as the car. For the first step of this research, the analysis of the crash elements have been performed. Also the longitudinal collapse force and mode is important point for whole carbody structure to guarantee the lower force at end part rather than the main passenger area. The carbody quasi-static collapse analysis and real test has been performed in the research. The crash elements FEA and test has been performed as well. After the initial Analysis and test, the correlation analysis between the FEA and test has been performed by FEA tunning. All this result will be used for real crashworthiness design for carbody structure.

• Proceedings of the KSR Conference
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• 2003.10c
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• pp.446-454
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• 2003

This paper derived a theoretical method to estimate structural characteristics of carbody members when material substitution designs were performed, and verified the theoretical method with finite element analyses. For important factors in rolling stock design, such as bending stiffness, natural frequency, bending strength and buckling strength, some performance indices to estimate structural behaviors were developed in order to derive an equivalent design in spite of material substitutions. The developed method was used to reduce the weights of carbody components, as example problems, by substituting the aluminium alloy for the structural steel. The analysis results of the examples show that the proposed technique gives a reasonable initial guess in the case of a material substitution design.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.37 no.9
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• pp.1099-1107
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• 2013

This study proposes a weight reduction design for urban transit, specifically, a Korean EMU carbody made of aluminum extrusion profiles, according to size optimization and useful material changes. First, the thickness of the under-frame, side-panels, and end-panels were optimized by the size optimization process, and then, the weight of the Korean EMU carbody could be reduced to approximately 14.8%. Second, the under-frame of the optimized carbody was substituted with a frame-type structure made of SMA 570, and then, the weight of the hybrid-type carbody was 3.8% lighter than that of the initial K-EMU. Finally, the under-frame and the roof-panel were substituted with a composite material sandwich to obtain an ultralight hybrid-type carbody. The weight of the ultralight hybrid-type carbody was 30% lighter than that of the initial K-EMU. All the resulting carbody models satisfied the design regulations of the domestic Performance Test Standard for Electrical Multiple Unit.