• Proceedings of the KSR Conference
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• 2002.05a
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• pp.378-385
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• 2002

오늘날 차량의 경량화를 위해서 알루미늄 차체를 사용하는 것은 필수적인 결정처럼 되어버렸다. 차체에 사용되는 알루미늄 압출재의 형상은 아주 다양하게 제작이 가능하다. 그러나, 다양한 형상이 가능한 만큼 설계 엔지니어에게는 결정하기 어려운 문제가 되어버린다. 이제 알루미늄 차체의 사용이 보편화되어가는 시점에 차체의 개념설계 단계에서 압출재형상의 토폴로지를 결정하는 조직적인 방법이 제시될 시기가 되었다. 본 논문에서는 토폴로지 최적화란 기법을 이용하여 알루미늄 차체의 형상을 결정하는 조직적인 방법에 대한 가능성을 검토하고자 한다. 간단한 예제에서 주어진 하중조건하에서의 압출재의 토폴로지 최적화를 시도하여 몇 가지 결론을 이끌어 내었다.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.370-377
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• 2002

오늘날 차량의 경량화를 위해서 알루미늄 차체를 사용하는 것은 필수적인 결정처럼 되어버렸다. 차체에 사용되는 알루미늄 압출재의 형상은 아주 다양하게 제작이 가능하다. 그러나, 다양한 형상이 가능한 만큼 설계 엔지니어에게는 결정하기 어려운 문제가 되어버린다. 주어진 하중조건하에서 최적의 형상을 설계하는 방법을 찾는 것은 이제 알루미늄 차체의 사용이 보편화되어가는 시점에 매우 중요한 일이 된 것이다. 본 논문에서는 형상최적설계란 도구를 사용하여 압출재 형상을 설계하는 방법에 대한 가능성을 살펴보고자 한다. 몇 개의 간단한 예제를 통하여 가능성을 점검하였고, 분석을 통하여 몇가지 결론에 도달하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.2
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• pp.213-221
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• 2011

In this study, we discussed the weight reducing of a urban railway-car body, in particular, of the Korean EMU, by optimizing topology and size of aluminum extrusion profiles. The heaviest parts of aluminum railway-car bodies, i.e., the base plate of underframe and side panels of side frame composed of double skin structures are considered for optimization. Topology optimization process is applied to obtain get an optimized rib structure for the base plate. The thickness of ribs and plates of the topologically optimized base plate and the existing side panel are also optimized by employing the size optimization process. The results are verified by comparing the maximum von Mises stresses and maximum deformation in the case of the existing design with those in the case of the optimized design. It is shown that the weight of a base plate and side panel can be reduced by 12% and that the weight of the whole car body can be reduced by 8.5%.

• Composites Research
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• v.21 no.4
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• pp.1-6
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• 2008

This paper explains fire safety tests of a hybrid composite train carbody with carbon/epoxy sandwich bodyshell and stainless steel underframe. In this study, a large scale mock-up was used to evaluate the fire safety of the composite train carbody. The test was conducted to the bare composite carbody mock-up without interior facilities and the fully equipped one. Tile fire propagation and temperature distribution of the carbon/epoxy bodyshell and the glass phenol interior panels was evaluated under the real fire accident scenario. The test scenario was based on the DaeGu subway fire accident. From the tests, both the surface temperature of the interiors and the composite bodyshell wore lower than tile ignition temperature. In addition, the fire spread along the surface of the interiors and bodyshell was not occurred.

• Journal of the Korean Society for Railway
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• v.15 no.4
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• pp.323-328
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• 2012

The purpose of this study is to develop automated structural design and analysis aided-program of aluminum extrusion carbody structures for railway vehicle. This developed program is called "AUTO-RAP" and could perform simultaneously structural design and verification for railway carbody structures made of aluminum extrusion independent of expertise and experience of design engineers. Design engineers are able to conduct the knowledge-based design by providing database of existing aluminum extrusion or user-defined function. The design verification is automatically programmed to evaluate its structural integrity according to Korean Railway Safety Law or Urban Transit Safety Law. In addition, this program could automatically generate an executable file of various commercial finite element programs such as ANSYS and ABAQUS and CAD files such as .stp and .iges by GUI environment applications using MFC(Microsoft Foundation Classes). In conclusion, it is expected to contribute to reduce product design cost and time of carbody structures aluminum extrusions in railway industry.

• 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.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.7
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• pp.3197-3202
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• 2013

When car builder designs the large carbody structure of railway vehicles, it is necessary to optimize the damping characteristics through the analysis of structure borne noise such as sound pressure level(SPL). This paper is a study on the structure borne noise analysis by characterizing the damping of double skin aluminum extruded panels for rolling stock carbody. The normalized SPL was calculated based on the simple source theory using measured mechanical mobility parameters from vibration tests(i.e. point, transfer and modal mobility). The reduced SPL was predicted by using finite element method by applying loss factor of damping material into laminated shell elements. It was found out that the damping material coated on the panels like underframe, which part is seriously affected by vibration during train run, took effect to reduce noise level.

• Journal of the Korean Society for Railway
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• v.13 no.2
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• pp.131-138
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• 2010

Recently, extruded aluminium-alloy panels have been used in the car bodies in order to meet the needs for the speed-up and light-weight of the railway vehicles. Most of the car bodies were jointed by arc weldings, like GMAW (GasMetal Arc Welding) and GTAW (Gas Tungsten Arc Welding), but these weldings became fairly worse the mechanical properties of the junction than the base metal. Nowadays, FSW (Friction Stir Welding), which is superior to the arc weldings, has been applied in the railway vehicles. In this study, the mechanical properties of the joints in both FSW and GMAW for A6005 extruded aluminium-alloy sheets have discussed. In addition, the relationships between the welding conditions and the mechanical properties for the joint of FSW have analyzed through the sensitivity analysis. It can be concluded that the mechanical properties for the joint of FSW are better than those of GMAW and the welding speed is the most sensible welding condition in the process of FSW.

• Proceedings of the KIEE Conference
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• 2007.10c
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• pp.18-21
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• 2007

철도차량의 경량화를 위해서 오늘날 알루미늄 압출재의 사용이 증가하고 있는 추세이며, 이를 통한 차체 제작이 일반화되고 있다. 경량화에 대한 요구는 더욱더 가속화되고 있으며, 특히 자기부상열차의 경우 환경규제 및 에너지 효율성 증대의 측면에서 경량화가 더욱 절실히 요구되고 있다. 그러나, 알루미늄 압출의 특성상 폭 대비 두께에 대한 제약이 따르므로 추가 경량화를 위해서는 알루미늄 압출재의 구조적인 연구가 필요하다. 따라서, 본 연구에서는 중공형 알루미늄 압출재의 내부에 Rib 형상에 따른 굽힘 특성을 비교함으로써 알루미늄 압출재의 경량화를 이루고자 하였다.

• Proceedings of the KSR Conference
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• 2011.10a
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• pp.2672-2678
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• 2011

Carbody of rolling stock has been gradually changed as whole wood, steel frame with wood car body, whole steel car body with rivet and whole monocoque carbody with welding. And also mild steel has been used widely to material of structure, but usage of stainless and aluminium which have lightweight and high corrosion resistance is being increased lately. Structure is being commercialized to AED(All Extrusion Design),whole double skin with hollow excluded shape such as aluminium structure from SSD(Sheet Stringer Design), single skin consists of traditional frame and outside plat. Traditional aluminium carbody had many problems from reduced strength in welding combination section because car body is consist of small extruded material affected heat by welding. On this study, we proposed the plan to improve the body strength and quality with large-scale aluminium extruded material by minimizing welding concentration in combination section.