• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.1079-1080
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• 2009

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2013.04a
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• pp.438-439
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• 2013

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2011.06a
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• pp.1567-1568
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• 2011

• 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 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.

• Journal of the Korean Society for Precision Engineering
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• v.23 no.5 s.182
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• pp.51-58
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• 2006

The necessities for heightening fuel efficiency as well as lightweight design, lead to an increase of the use of aluminum alloys in the automobile industry. Extruded aluminum profile channels are used widely for the design of frame parts as lightweight assemblies, especially if a high stiffness is needed. While many applications can be realized with forming of hollow square-sectioned extruded profiles such as a stretch bending and a hydro-forming, some applications demand the use of a press bending which can be hardly found in the previous study. In this study, by introducing the use of a press bending into car sub-frames, the demands for higher accuracy as well as higher flexible method than the conventional methods will be satisfied. With respect to the design of sub-frames, the process planning was performed from the shape of a sub-frame product. The designed processes were analyzed by the commercial FEM code, DEFORM-3D. Forming dies for the each process were designed and prototypes of sub-frames were manufactured by the verified farming process. In addition, some of the important features of design parameters in the press bending were reviewed.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.120-120
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• 2012

차세대 가속기용 언듈레이터 진공용기는 In-vacuum 또는 out-vacuum 형태로 제작되며 out-vacuum 언듈레이터 진공용기는 얇고 길이가 긴 모양을 가진다. 이 진공용기는 완전한 비자성체가 요구되므로 주로 알루미늄 합금재로 제작된다. 또한 언듈레이터의 자석 간극은 그 중심에서 자기장의 세기가 극대화 되도록 최대한 근접하게 제작하기 때문에 진공용기의 단면도 이에 따라 매우 작고 또 진공용기의 두께도 매우 얇아야 만 한다. 현재 설계하고 있는 PAL-xFEL x-선 언듈레이터 용 진공용기는 내부 단면의 최대 크기가 5.2 mm, 두께는 $0.5mm{\pm}0.05mm$ 이고 길이 6,000 mm에서 그 평탄도가 0.1 mm 이하가 되어야 한다. 이 같은 진공용기를 제작하기 위하여서는 초정밀 압출, 후 평탄화 공정, 내표면 경면 처리, 초정밀 기계가공, 진공용접이 핵심공정이다. 본 논문에서는 알루미늄 6063-T5을 재료로 이 같은 초정밀 진공용기를 제작하는 전체 공정에 대한 국외 기술 동향과 국내 적용 가능한 공정을 조사하여 보고하고자 한다.

• Composites Research
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• v.32 no.1
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• pp.29-36
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• 2019

The purpose of this paper is to suggest a lightweight design for the aluminum extrusion carbody structure of a double deck high-speed train using material substitution and size optimization method. In order to conduct material substitution, the topology optimization was used to determine the application parts of sandwich composites at the carbody structures. The results of analysis showed that sandwich composites could be applied at roof and 2nd underframe. The size optimization was used to determine thickness of the aluminum extruded and carbon/epoxy composite. The design variable, state constraint and objective function were formulated to solve the size optimization, and then, the feasible design was presented by these conditions. The results of the lightweight design showed that the weight of double deck high-speed train hybrid carbody could be reduced by 2.18(17.70%) tons.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.04a
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• pp.729-733
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• 2012

Frame structures of High speed train are constructed from corrugated panel and aluminum extruded panel, which have high bending stiffness. Transmission loss of those panels, however, is less satisfactory than other panels with same mass per unit area. Therefore, this study predicted transmission loss of aluminum extruded panels using Finite element method. Specifically, we modeled acoustic cavity above a radiation surface and analyzed correlation between T-slot and transmission loss. Moreover, we examined the effect of boundary condition changes of the structure on transmission.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05e
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• pp.44-48
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• 2003

할로겐 난연재료 및 고분자의 연소시 Dioxine의 문제점이 대두되고 있어 유럽국가를 중심으로 할로겐 난연제 사용을 규제하고 있다. 환경과 인체에 대한 안정성을 고려해서 저 유해 가스화, 저 발연화, 저 부식성, 리사이클링 등을 겸비한 제품의 개발로 관심이 모아지고 있는 실정이다. 본 연구에서는 환경친화적인 금속화합(수산화 알루미늄)을 사용하여 연소시 발생할 수 있는 난연성, 무독성, 소연성 등을 함량별로 확인하고 난연재가 증가할수록 취약한 기계적 물성 보완을 위해 moisture cure crosslikable 기술로 케이블절연 및 자켓 피복층 특성을 증가 시켰다. 그러나 수산화알루미늄 함량이 증가할수록 기계적 물성과 기타 특성도 감소하는 경향을 보이고 있어 최적의 난연제 조성함량이 약 130~150 phr정도에서 우수한 결과를 확인하였다. 또한 moisture cure agent는 전선압출 시 표면에 scorch 및 장기 압출에 영향을 주므로 약 1.5~2phr 범위에서 처방하는 것이 우수하다. 원료투입 후 mixing 공정 중에서는 온도관리가 매우 중요하므로 되도록 믹싱 온도를 $130^{\circ}C$ 이하를 유지해야한다. 온도는 수산화알루미늄의 분산성과 케이블 피복압출 시 표면에도 영향을 주기 때문이다 본 연구는 이런 작업방법을 통해 친환경 가교 난연콤파운드가 비(比) 가교된 제품에 비해 특성이 증가되는 것을 입증할 수 있었다.