• Proceedings of the Korean Society For Composite Materials Conference
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• 2005.11a
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• pp.251-255
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• 2005

본 연구는 한국형 틸팅 차량의 하이브리드 복합재 차체에 대한 비용 모델링과 전주기 평가{LCA}를 기존 차체 재질인 스틸 및 알루미늄 재질과 병행하여 수행였다. 원자재 생산에서 차체제작, 수명이 끝나는 시점까지의 사용에 대한 모든 단계에서의 비용을 분석했다. 개발과정을 거쳐 향후 양산 예정인 5년 동안 년간 90대정도의 생산량에 대해 금속 차체, 2종의 복합재 차체에대해 비교하였다. 2종의 복합재 차체는 하이브리드 스틸-복합재 구조와 전체 복합재 차체를 나타낸다. 또한, 이 두 경우 모두에 대해 오토클레이브, 진공 성형, 레진 인퓨젼 공법의 성형에 대해 분석하였다. 제작시의 모든 성형 공법에 대해 하이브리드 차체는 전체 복합재 차체보다 4${\sim}$6 % 비용이 낮았다. 전체 복합재 차체의 경우, 레진 인퓨젼의 경우가 오토클레이브에 대해서는 11%낮은 가장 낮은 제작 비용이 소요되었다. 비용-전주기 분석을 통해 전체 복합재 차체는 가장 높은 제작비용이 소요되고 사회 경제학적 측면에서 전체 전주기 비용과 환경영향은 단순 차량 구입 비용보다 더 중요한 변수이며 전체 복합제 차체가 분명한 최적의 해답 임을 확인하였다.

• Proceedings of the KSR Conference
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• 2005.11a
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• pp.1103-1108
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• 2005

본 연구는 한국형 틸팅 차량의 복합재 적용 차체에 대한 비용 모델링과 전주기 평가(LCA)를 수행하였다. 원자재 생산에서 차체 제작, 수명이 끝나는 시점까지의 사용에 대한 모든 단계에서의 비용을 분석했다. 5년 동안 년간 90대의 생산량에 대한 금속 차체, 2종의 복합재 차체에 대해 비교하였다. 2종의 복합재 차체는 하이브리드 스틸-복합재 구조와 전체 복합재 차체를 나타낸다. 또한, 이 두 경우 모두에 대해 오토클레이브, 진공 성형, 레진 인퓨젼 공법의 성형에 대해 분석하였다. 제작시의 모든 성형 공법에 대해 하이브리드 차체는 전체 복합재 차체 보다 $4\~6\%$ 비용이 낮았다. 전체 복합재 차체의 경우, 레진 인퓨젼의 경우가 오토클레이브에 대해서는 $11\%$ 낮은 가장 낮은 제작 비용이 소요되었다. 비용-전주기 분석을 통해 전체 복합재 차체는 가장 높은 제작비용이 소요되고 사회 경제학적 측면에서 전체 전주기 비용과 환경영향은 단순 차량 구입 비용보다 더 중요한 변수이며 전체 복합재 차체가 분명한 최적의 해답 임을 확인하였다.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.36 no.11
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• pp.1335-1343
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• 2012

In this study, the lightweight modular design of hybrid railway carbody structures made of sandwich composites and aluminum extrusions was investigated by using topology and size optimization techniques. The topology optimum design was used to select the best material for parts of the carbody structure at the initial design stage, and then, the size optimum design was used to find the optimal design parameters of hybrid carbody structures using first-order and sub-problem methods. Through the topology optimization analysis, it was found that aluminum extrusions were suitable for primary members such as the underframe and lower side panel module to improve the stiffness and manufacturability of the carbody structures, and sandwich composites were appropriate for secondary members such as the roof and middle side panel module to minimize its weight. Furthermore, the results obtained by size optimization analysis showed that the weight of hybrid carbody structures composed of aluminum extrusions and sandwich composites could be reduced by a maximum of approximately 17.7% in comparison with carbody structures made of only sandwich composites.

• 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.

• Composites Research
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• v.17 no.1
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• pp.18-28
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• 2004

In order to evaluate the strength of carbody structures of railway rolling stock made of laminated fiber-reinforced composite materials, total laminate approach was introduced. Structural analyses were conducted to check the basic design of hybrid composite carbody structures of the Korean Tilting Train eXpress(TTX) with the service speed of 180km/h. The mechanical tests were also conducted to obtain strengths of composite laminates. The results show that all stress components of composite carbody structures are inside of failure envelopes and total laminate approach is recommended to predict the failure of hybrid composite carbody structures at the stage of the basic design.

• 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.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.28 no.6
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• pp.807-815
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• 2004

In order to evaluate the static stability of hybrid carbody structures of Korean Tilting Train eXpress(TTX) caused by degradation of composites under ground environments, T300/AD6005 graphite/epoxy composite specimens were exposed to accelerated environmental conditions including ultraviolet radiation, temperature and moisture fer 2000 hours. It was found that the stiffness and strength of composites after aging were lower than those of unexposed specimens, and decreased as the aging time increases. The values of the degraded properties were used in the static analysis to check the static stability of hybrid carbody structures caused by environmental degradation of composites. The results shown that the structural stability of hybrid carbody structures was affected by the degradation of composites after exposure to accelerated aging environments.

• Composites Research
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• v.18 no.6
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• pp.19-25
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• 2005

This paper has performed an experimental study on the hybrid composite carbody of Korean tilting railway vehicle. The hybrid composite carbody has the length of 23m and is comprised of a 40mm-thick aluminium honeycomb core and 2mm-thick woven fabric carbon/epoxy face sheet. In order to evaluate the structural behavior and safety of the hybrid composite carbody, the static load tests such as vertical load, end compressive load, torsional load and 3-point support load tests have been conducted. The test was performed under Japanese Industrial Standard (JIS) 17105 standard. from the tests, the maximum deflection was 12.3mm and the equivalent bending stiffness of the carbody was $0.81\times10^{14}\;kgf{\cdot}mm^2$. The maximum strain of the composite body was below $20\%$ of failure strain of the carbon/epoxy face sheet.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1634-1642
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• 2009

본 연구는 자체재질로 복합재 적용한 경우를 기존의 금속구조 차체와 25년 운행기간을 기준으로 환경영향을 비교평가하였다. 본 연구는 알루미늄, 스틸, 하이브리드 복합재, 전체 복합재 인 종 4종의 자체를 고려하였다 네가지 차체 시나리오에 대해 원자재 생산, 차체 제작, 25년 사용 단계, 폐기까지의 환경영향에 대해 LCA 기법을 사용하여 평가하였다. 모든 시나리오 경우, 사용단계가 환경영향 카테고리를 좌우했다. 전제 복합재 시나리오가 매립 또는 소각에 대한 가장 낮은 영향을 주었다. 복합재 차체는 금속자제와 비교해 환경영향 측면에서 30$\sim$50 % 개선효과를 보였다.

• Journal of the Korean Society for Railway
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• v.9 no.6 s.37
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• pp.635-643
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• 2006

In this paper, a theorectical approach is studied to predict structural performances and weight-reduction rates of hybrid bodyshells in case that the materials of roof structures are substituted. To determine other light-weight materials to be substituted for the original roof materials, bending and twisting deformations are considered under constant stiffness and strength conditions, which derive some new weight-reduction indices from a structural performance point of view. The indices derived to estimate the weight-reduction can be utilized as a good criterion at the conceptual design for material substitution of the roofs.