• 한국산학기술학회논문지
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• 제14권7호
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• pp.3197-3202
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• 2013

철도차량 차체 설계시 음압레벨에 따른 소음해석을 통한 차체 패널의 감쇠특성을 최적화하는 것이 필요하다. 본 논문은 철도차량 차체용 알루미늄 더블스킨 압출패널의 진동감쇠특성 해석을 통한 철도차량 차체의 구조소음 해석에 관한 연구이다. 주파수응답 가진시험을 통하여 측정된 기계적 모빌리티 값인 포인트 모빌리티, 트랜스퍼 모빌리티, 모달 모빌리티와 단순음원이론을 사용하여 정규화된 음압을 계산하였다. 도포용 감쇠재의 감쇠값을 라미네이티드 쉘요소에 사용하여 유한요소해석을 수행함으로써, 감쇠처리에 의한 소음감소수준 예측을 하였다. 또한 실제 차량 구조와 유사한 고정경계조건의 감쇠특성해석을 통하여 열차주행시 발생하는 진동의 영향을 크게 받는 언더프레임과 같은 부위에 일정 두께의 감쇠재 코팅이 진동 및 소음억제에 큰 효과가 있을 것으로 사료된다.

• 한국자동차공학회논문집
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• 제17권5호
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• pp.115-126
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• 2009

This paper studied on the application of the crashworthiness regulations of Korean Railway Safety Law and Urban Transit Safety Law to the urban Maglev vehicle of KIMM. The Urban Maglev vehicle has to comply with the crashworthiness regulations for urban transit vehicles. The collision load cases have been simulated by using explicit finite element analysis. From the numerical results, the crashworthiness regulations of the Urban Transit Safety Law were completely satisfied, but maximum crash pulse requirement in 25 km/h crash event and no plastic deformation requirement in 10 km/h crash event in the Korean Railway Safety Law were not. If a commercial urban Maglev vehicle is developed in the near future, it is necessary that some soft buffing and energy absorbing devices are adopted in its front end so as to satisfy the crashworthiness regulations of the Korean Railway Safety Law.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.387-392
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• 2005

Double-deck train have studied in the next generation train in KRRI. Double-deck train have more seat capacities compared with single deck vehicles and is a efficient, reliable and comfortable alternative train. Because of heavy weight, weight minimization of double-deck train carbody is imperative to reduce cost and extend life-time of train. Weight minimization problem of the double-deck train car-body is required to decide 66 design variables of thicknesses for large aluminum extruded panel while satisfying stress constraints. Design variables are too many and one execution of structural analysis of double-deck train carbody is time-consuming. Therefore, we adopt approximation technique to save computational cost of optimization process. Metamodels such as response surface model (RSM) and kriging model are used to approximate model-based optimization is described. RSM is easy to obtain and expressed explicit function, but this is not suitable for highly nonlinear and large scaled problems. Kriging model employs an interpolation scheme and is developed in the fields of spatial statistics and geostatistics. Target of this design is to find optimum thickness of AEP to minimize weight of doulbe-deck train carbody. In this study, meta model techniques are introduced to carry out weight minimization of a double-deck train car-body.

• 한국산학기술학회논문지
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• 제11권10호
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• pp.3756-3760
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• 2010

본 논문은 조가선을 이용한 전기철도의 전력선 통신을 위한 네트워크 설계를 제안한다. 전기철도에서 필수적인 전차선 및 조가선을 이용하여 전력선 통신에 대한 타당성 검토를 선행연구로 수행하였다. 이를 위해 우선 무가압상태에서 조가선에 신호결합기를 취부하여 양방향 데이터 통신을 구현하였다. 데이터 전송속도가 양호하게 나타났으며 이를 토대로 전력선 통신을 위한 주요 구성품을 제시하고 네트워크 설계를 제안하였다. 향후 네트워크 설계에 대한 타당성을 확보하기 위해 지속적인 연구를 수행하고자 한다.

• Journal of Mechanical Science and Technology
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• 제19권spc1호
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• pp.437-443
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• 2005

Controlling the friction between wheel and rail is direct and very effective measures to improve the curving performances of railway trucks, because the curving performances depend much on friction characteristics. Authors have proposed a method, 'friction control', which utilizes friction modifier ($KELTRACK^{TM}$ HPF) with onboard spraying system. With the method, not only friction coefficient, but also friction characteristics can be controlled as expected. In this study, MBD simulation is very valuable tool to foresee the effect of the control in advance of experiment with real car. And the creep characteristics of wheel/rail contact with the friction modifier takes very important role in the simulation. In this paper, authors propose a theoretical model of wheel/rail contact condition considering the creep characteristics of friction modifier, which is derived the application of principle tribological theories.

• 한국자동차공학회논문집
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• 제19권5호
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• pp.100-112
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• 2011

This paper studied on a theoretical approach to predict structural performances and weight -reduction rates of hybrid bodyshells in case that the material of underframe structure is substituted. To choose other light-weight materials to be substituted for the original underframe material, compressive, 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. Next, these weight-reduction indices were verified using the finite element analyses of some simplified examples. It is shown that the derived indices to estimate the weight-reduction can be utilized as a good criterion for material substitution of the underframe at a basic design stage.

• 한국전산구조공학회논문집
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• 제17권2호
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• pp.171-181
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• 2004

본 연구에서는 기존의 철도차량구조에 경량소재를 적용하여 설계를 검토할 때, 각 소재의 성질이 차체구조의 경량화에 미치는 영향과 그 정도를 정량적으로 분석하여 개념설계단계에서 소재대체 설계 효과를 예측하는 방법을 개발한다. 전체 차체구조에 대해서는 굽힘변형, 압축변형, 비틀림 변형을 고려하여 소재를 변경할 때, 또 주요 골조 구조 부재에 대해서는 굽힘변형, 압축변형, 좌굴붕괴를 고려하여 소재와 단면형상을 변경할 때 경량화 특성을 분석할 수 있는 방법을 체계화였다. 차체구조 또는 골조부재의 변형 양상에 대한 강성 및 강도 조건을 경량화 지수와 연계하여 표현함으로써 각 재료와 부재의 형상이 가지는 기계적 특성과 장단점을 용이하게 분석할 수 있도록 하였다.

• 대한안전경영과학회지
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• 제12권3호
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• pp.321-326
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• 2010

Government evaluate annually a performance of government's R&D(Research & Development) and decide a budget and progress. So, a performance target setting of R&D is very important at the planning, The basic performance target setting of railroad R&D is clear. However, a scientific and technological performance target setting of railroad R&D is very difficult and a reasonable level of it can not be judged. Therefore, this study will suggest a solution for a scientific and technological performance target setting of railroad R&D through regression analysis of successfully finished railroad R&D, after judging a reasonability of a scientific and technological performance through comparing railroad R&D with the other R&D.

• 한국안전학회지
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• 제31권3호
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• pp.130-135
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• 2016

It is very hard to analyze the train derailment safety quantitatively at the curved section because of the diversified affect parameters including the complex interaction between wheel and rail, the train conditions such as the shape of wheel, suspension system, the track conditions such as the radius of curve, cant, transition curve, and the operation conditions, etc. Two major factors related to the running safety of railway vehicle are classified as the railway vehicle and the track condition. In this study, when the railway vehicle passing through curves of actual track condition of subway line NO.3 in seoul ($Yeonsinnae{\leftrightarrow}Gupabal$), the effect that has influence on running safety depending on rail inclination. The analysis result of 1/40 rail inclination condition is more favorable on running safety than other rail inclination conditions because derailment coefficient and wheel unloading ratio are the lowest.

• 전기학회논문지
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• 제64권12호
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• pp.1804-1809
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• 2015

The study in railway system to apply a fuel cell system with high efficiency and mobility than other renewable energy is being actively conducted. It is needed a analysis on load characteristics and control method of rolling stock in order to apply to rolling stock. This paper presents study on control small-scale prototype power converter electric railway vehicle using fuel cell generation system. Experiment is conducted through real fuel cell generation system and reference speed applying the driving curve of the actual electric railway vehicle was applied. Also, output voltage of boost converter is controlled considering characteristic of fuel cell. And it was confirmed characteristic according to powering and regeneration of inverter.