• 한국지반공학회:학술대회논문집
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• 한국지반공학회 2008년도 춘계 학술발표회 초청강연 및 논문집
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• pp.587-598
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• 2008

In the trackbed design using elastic multi-layer model, the stress-dependent resilient modulus is an important input parameter, which reflects substructure performance under repeated traffic loading. The resilient moduli of crushed stone and weathered granite soil were developed using nonlinear dynamic stiffness, which can be measured by in-situ and laboratory seismic tests. The prediction models of resilient modulus varying with the deviatoric or bulk stress were proposed (Park et al., 2008). To investigate the performance of the prediction models proposed herein, the elastic response of the test trackbed near PyeongTaek, Korea was evaluated using a 3-D nonlinear elastic computer program (GEOTRACK) and compared with measured elastic vertical displacement during the passages of freight and passenger trains. The material types of the test sub-ballasts are crushed stone and weathered granite soil, respectively. The calculated vertical displacements within the sub-ballasts are within the order of 1mm, and agree well with measured values with the reasonable margin. The prediction models are thus concluded to work properly in the preliminary investigation. The prediction models proposed for resilient modulus were verified by the comparison of the calculated vertical displacements with measured ones during train passages.

• 한국정밀공학회지
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• 제18권3호
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• pp.84-89
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• 2001

Studied in this paper was the vehicle dynamics simulation for development of single axle bogie using the multi-body dynamics simulation program(VAMPIRE). Single axle bogie vehicle is to the crew of freight vehicle. Method of analysis for dynamic behaviors of vehicle having single axle bogie was carried by UIC(International Union of Railways) code 518 and results of analysis were presented in terms of the hunting stability and the derailment ratio and the sum of wheel/rail lateral force. The results of analysis meet the criteria proposed by UIC.

• 한국철도학회논문집
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• 제20권3호
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• pp.299-310
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• 2017

본 연구에서는 3-piece 마찰 웨지 화차의 주행성능을 예측하기 위해 ADAMS/View에서 독립하중 마찰 웨지 모델을 개발하였다. 마찰 웨지 모델은 볼스터의 좌우, 수직방향에 따른 마찰을 각각 구현해줄 수 있다. 개발된 마찰 웨지 모델은 ADAMS/Rail 차량 모델에 적용하여 동역학 해석 결과를 얻었다. 대상차량은 임계속도 210km/h를 가진다. 직선 안정성 해석에서 UIC518에 근거해 차체의 횡, 수직방향 한계 가속도에 만족하는 것을 확인하였다. 300R 곡선에서 해석 적용 속도는 70km/h로 UIC518에 근거해 차체, 대차의 한계 가속도에 만족하였다. 또한 "철도차량 안전기준에 관한 규칙"의 윤중감소율, 횡압, 탈선계수에 만족하는 것을 확인하였다.

• Structural Engineering and Mechanics
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• 제60권2호
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• pp.237-249
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• 2016

There are constraints on truck weight, axle configurations and size imposed by departments of transportation around the globe due to structural capacity limitations of highway pavements and bridges. In spite of that, freight movers demand some vehicles that surpass the maximum size and legal weight limits to use the transportation network. Oversized trucks serve the purpose of spreading the load on the bridge; thus, reducing the load effect on the superstructure. For such vehicles, often a quick structural analysis of the existing bridges along the traveled route is needed to ensure that the structural capacity is not exceeded. For a wide vehicle having wheel gage larger than the standard 1830 mm, the girder distribution factors in the design specifications cannot be directly used to estimate the live load in the supporting girders. In this study, a simple approach that is based on finite element analysis is developed by modifying the AASHTO LRFD's girder distribution factors for slab-on-steel-girder bridges to overcome this problem. The proposed factors allow for determining the oversized vehicle bending moment and shear force effect in the individual girders as a function of the gage width characteristics. Findings of the study showed that the relationship between the girder distribution factor and gage width is more nonlinear in shear than in flexure. The proposed factors yield reasonable results compared with the finite element analysis with adequate level of conservatism.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.12-15
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• 2005

In April 1, 2004, age of high-speed railway was opened to korea railroad. The railroad is a means of large transportation which has many talents such as a safety and a regularity. That is a results from various confidential performance tests and evaluations of the system. The railroad system consist of various subsystems - vehicle, power supply, signal, communications, track structures, operations, etc. Among them, as an item of safety evaluation there is a measurement of wheel/rail farce, so called a measurement of derailment coefficient. This is a very important item because a derailment of a train will bring about a big accident. Especially it is more important in high speed rail of which operation speed is over two times as fast as existing rail. In this paper, examined speed elevation possibility use the korean style high speed railway vehicle for reduce the running time of high-speed railway between high speed line and conventional line.

• 한국정밀공학회지
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• 제33권9호
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• pp.739-744
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• 2016

The truck that is used as running equipment for tank freight car support is a core structural part that supports the load of the car body and significantly influences the safety of freights and vehicles, as well as their running performance. Running equipment is composed of truck frames, wheels and wheel axles, independent suspensions, and brakes. Among these components, the truck frame supporting the load of the vehicles and freights may be the most important component. This study was carried out to analyze the structure of truck frames and to determine whether they are safe when the maximum vertical load, braking part load, and the front and rear load are applied to truck frames. This was achieved by subjecting the truck frames to stress tests and then measuring the stress on each part. The results of the stress tests showed that truck frames have a safe vehicle load design.

• 한국철도학회논문집
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• 제10권6호
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• pp.692-700
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• 2007

국내에서 개발된 한국형 틸팅열차는 현재 시제차량 제작을 마치고, 충북선을 시작으로 시운전 시험이 단계적으로 진행되고 있다. 시운전 시험에서는 한국형 틸팅열차의 시스템 안정화를 위해 차량 외에 궤도, 구조물, 전차선, 신호 등 각 시스템 상호간의 인터페이스 검증이 필요하며, 선로구축물 분야에서는 개발차량의 증속이 궤도구조에 미치는 영향을 비롯한 궤도부담력 검토를 통해 궤도구조의 안정성과 주행안정성 평가가 수행되어야 한다. 따라서 본 연구에서는 틸팅차량이 기존선 선로중 취약개소인 곡선부를 증속할 때 궤도에 미치는 영향을 검토하고자, 현재 시운전 시험이 진행되고 있는 충북선 및 호남선 구간 중 일부 선호를 대상으로 틸팅차량 주행이 기존선 궤도성능에 미치는 영향을 분석하였다. 틸팅열차, 고속열차 및 일반열차(무궁화, 화물)가 기존선 주행시 궤도각부의 거동특성을 파악하기 위해 윤중, 횡압, 레일 휨응력, 레일 수직 횡변위, 침목 수직변위 등을 측정하여 비교 분석함으로써 향후 기존선 속도향상을 위해 투입될 틸팅차량이 궤도에 미치는 영향을 평가하였다.