• 제목, 요약, 키워드: Railway vehicle

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고속철도차량용 차륜 불평형에 의한 동적 거동 특성 연구 (Study on the Dynamic Behavior Characteristics due to the Unbalance High Speed Railway Vehicle Wheel)

  • 이승일;송문석
    • 한국산학기술학회논문지
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    • v.17 no.7
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    • pp.175-181
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    • 2016
  • 회전체는 질량 중심선이 축의 기하학적 중심선과 일치하지 않을 때 불평형이 발생한다. 윤축은 두 개의 차륜과 한 개의 차축으로 조립되어 철도차량을 주행시키는 회전체 역할을 하고, 차륜 재질의 불균일, 마모, 윤축 조립과정의 오차 등으로 인해 불평형이 발생할 수 있다. 또한 윤축은 축의 직경이 가늘고 고속으로 회전함으로 불평형 질량에 의한 진동의 영향이 더욱 두드러지게 나타나고 이로 인해 철도차량 고속 주행 시 주행안전성 및 주행거동에 영향을 미칠 수 있다. 그러므로 본 연구에서는 차륜 불평형이 고속철도차량의 동적 거동에 미치는 영향을 철도차량 다물체 동역학 해석 도구인 VI-Rail를 이용하여 해석을 수행하였다. 해석결과에서 차륜 불평형량이 증가할수록 철도차량 대차의 임계속도가 감소됨을 확인할 수 있었고, 차륜 불평형량이 주행 중 차량동적거동 악영향을 미침으로 고속주행에서는 반드시 차륜 불평형량에 대한 관리가 필요함을 확인할 수 있었다. 또한 이 연구로 차륜 불평형량의 정적 및 동적 관리 필요성을 국내 철도차량 운영기관에 제시하였다.

복선선로를 통과하는 열차에 의한 철도교량의 동적거동 (Dynamic Behavior of Railway Bridge Due to Trains Moving on Double Tracks)

  • 최창근;송명관;양신추
    • 한국철도학회:학술대회논문집
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    • pp.450-457
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    • 1999
  • In this study, the simplified method for 3-dimensional vehicle-bridge interaction analysis is utilized in the analysis of dynamic behavior of bridges in which the eccentricity of axle loads and the effect of the torsional forces acting on the bridge are included for the more accurate vehicle-bridge interaction analysis. Investigations mainly into the influence of vehicle speed on vehicle-bridge interactions are carried out for case that two trains move respectively on their tracks in the opposite direction.

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윤축의 소음 및 진동과 고속선 궤도불규칙간의 관계에 대한 기초연구 (A Relationship between the Noise and Vibration of a Wheelset and the Irregularity of a High-speed Railway: A Preliminary Research)

  • 이준석;최성훈;김상수;박춘수
    • 한국철도학회:학술대회논문집
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    • pp.409-417
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    • 2009
  • This paper is focused on a relationship between the noise and vibration of a wheelset and the railway irregularity of a high speed railway using a time-varying frequency transform for a preliminary research of the railway condition monitoring by an in-service high-speed railway vehicle. Generally, the monitoring has been performed by a special railway inspection vehicle or industrial engineers for railway maintenance. However, they have been limited at night due to the in-service high-speed railway vehicles, and too slow to monitor all of the section. To solve this problem, the monitoring should be performed by an in-service high-speed railway vehicle. For the research, the noise and vibration of a wheelset are utilized, because they are closely related to the railway condition. They are measured by using some microphones and accelerometers, and stored in an on-board data acquisition system. The signals are post-processed by a time-varying frequency analysis and compared with the result of a railway geometry and profile measurement system. From the comparison, it is able to observe the relationship between the noise and vibration of a wheelset and the irregularity of a high-speed railway. Also, some distinct frequency components are observed, which are not observed in the railway geometry and profile.

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철도차량 설계대안 선정에 대한 GHG 배출량 기반 환경 경제성 통합평가 사례연구 (A Case Study of Integration Assessment of Environmental Aspect and Cost Aspect Based on GHG Emission for Design Alternative Selection of a Railway Vehicle)

  • 최요한;이철규;이재영;김용기;정우성
    • 한국철도학회:학술대회논문집
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    • pp.606-612
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    • 2011
  • At the product design and development stage, the main criteria selecting a design alternative were performance aspect as well as cost aspect of a product. Ongoing new paradigm shifts such as low carbon green growth, climate change mitigation, sustainable society development urged considering environmental aspect of a product at the product design and development stage. Up to recently, only cost aspect except performance of a product was considered at the railway vehicle design process. Therefore, it is needed to develop a method that may consider environmental aspect of a product at the railway vehicle design process. Lee (2011) proposed that a method of an integration assessment of environmental aspect and cost aspect based on GHG emission instead of based on monetary value. This study conducted that apply the method of Lee (2011) to design alternative selection process of a railway vehicle. From the integrated view of environmental and cost aspect, the reference product and design alternatives are assessed and compared.

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김포도시철도 맞춤형 차량시스템 선정을 위한 발주방안 검토 (A study on measures to place an order for selection of tailor-made rolling stock systems for Gimpo urban transit)

  • 최시행;임병국;전서탁;박종혁
    • 한국철도학회:학술대회논문집
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    • pp.816-822
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    • 2010
  • A comprehensive review for the selection of urban rail vehicle systems that best suit Gimpo railway line is taking place with consideration of the project area characteristics in light of line planning, passenger demand, supply of rolling stock, and railway construction and operation. Various aspects of vehicle systems including passenger demand on concerned lines, regional characteristics, vehicle types, and railway construction and operational settings should be taken into consideration. In addition, request for the introduction of customized vehicle systems reflecting the convenience of transit users such as wide and hospitable inner space, low noise, flexible operation of 2 to 4 car train-set and eye catching slim bridge piers is increasing. A study on alternatives to place an order to opt for optimum rolling stock systems considering line characteristics of Gimpo City's urban railway and future passenger demand while meeting the needs of Gimpo City has been conducted.

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Effect of Crosswind on Derailment of Railway Vehicles Running on Curved Track at Low Speed

  • Hosoi, Takahiro;Tanifuji, Katsuya
    • International Journal of Railway
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    • v.5 no.2
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    • pp.93-101
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    • 2012
  • Owing to the lightening of railway vehicles and increased operation speeds, the reduction of running safety in the presence of crosswind is becoming an important problem. In particular, the running safety tends to decrease when vehicles run on curved track. When a crosswind acts on a vehicle negotiating a curve from the outer side, flange climbing can occur. In this study, a full-vehicle model was constructed using the multi-body simulation software SIMPACK, and a simulation of a bogie vehicle with two-axle trucks negotiating a curve was carried out to examine the running safety under the condition where a crosswind acts on the vehicle from the outer side of the curve. As a result, it was verified that the derailment coefficient of the first wheelset becomes large in the exit transition curve and the coefficient of the third wheelset does in the entrance transition curve, and this trend becomes pronounced at low operation speeds in the presence of a stronger crosswind. It was also shown that the critical derailment coefficients obtained by modified Nadal's formula considering the effect of attack angle become close to the actual derailment coefficients at the timing that flange climbing occurs.

철도차량의 곡선부 스킬 소음에 대한 속도의 영향 (Influence of the Speeds on the Curve Squeal Noise of Railway Vehicles)

  • 이찬우;김재철
    • 한국정밀공학회지
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    • v.28 no.5
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    • pp.572-577
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    • 2011
  • Curve squealing of inter-city railway vehicle is a noise with high acoustic pressure and rather narrow frequency spectra. This noise turns out to be very annoying for the people living in the neighborhood of locations and the passenger in railway vehicle where this phenomenon occurs. Squealing is caused by a self-exited stick-slip oscillation in the wheel-rail contact. Curve squeal noise of railway vehicles that passed by a factor of the speed limit, so to overcome in order to improve running performance is one of the largest technology. In the present paper, characteristic of squeal noise behavior at the Hanvit-200 tilting train test-site. Curve squealing of railway wheels/rail contact occurs in R400~ R800 curves with a frequency range of about 4~11 kHz. If the curve is less than the radius of wheel frail contact due to |left-right| noise level difference (dBA) shows a significant effect of squeal noise were more likely.

한국형 고속전철 현가장치 최적설계를 위한 반응표면모델과 유전자 알고리즘 모델에 관한 연구 (A study on the response surface model and the neural network model to optimize the suspension characteristics for Korean High Speed Train)

  • 박찬경;김영국;김기환;배대성
    • 한국철도학회:학술대회논문집
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    • pp.589-594
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    • 2004
  • In design of suspension system for KHST, it was applied the approximated optimization method using meta-models which called Response Surface Model and Neural Network Model for 29 design variables and 46 performance index. These models was coded using correlation between design variables and performance indices that is made by the 66 times iterative execution through the design of experimental table consisted orthogonal array L32 and D-Optimal design table. The results show that the optimization process is very efficient and simply applicable for complex mechanical system such as railway vehicle system. Also it was compared with the sensitivity of some design variables in order to know the characteristics of two models. This paper describes the general method for dynamic analysis and design process of railway vehicle system applied to KHST development, and proposed the efficient methods for vibration mode analysis process dealing with test data and the function based approximation method using meta-model applicable for a complex mechanical system. This method will be able to apply to the other railway vehicle system in oder to systematize and generalize the design process of railway vehicle dynamic system.

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Dynamic response of railway bridges traversed simultaneously by opposing moving trains

  • Rezvani, Mohammad Ali;Vesali, Farzad;Eghbali, Atefeh
    • Structural Engineering and Mechanics
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    • v.46 no.5
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    • pp.713-734
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    • 2013
  • Bridges are vital components of the railroads. High speed of travel, the periodic and oscillatory nature of the loads and the comparable vehicle bridge weight ratio distinguish the railway bridges from the road bridges. The close proximity between estimations by some numerical methods and the measured data for the bridge-vehicle dynamic response under the moving load conditions has boosted the confidence in the numerical analyses. However, there is hardly any report regarding the responses of the railway bridges under the effect of the trains entering from the opposite directions while running at unequal speed and having dissimilar geometries. It is the purpose of this article to present an analytical method for the dynamic analysis of the railway bridges under the influence of two opposing series of moving loads. The bridge structural damping and many modes of vibrations are included. The concept of modal superposition is used to solve for the system motion equations. The method of solution is indeed a computer assisted analytical solution. It solves for the system motion equations and gives output in terms of the bridge deflection. Some case studies are also considered for the validation of the proposed method. Furthermore, the effects of varying some parameters such as the distance between the bogies, and the bogie wheelset distance are studied. Also, the conditions of resonance and cancellation in the dynamic response for a variety of vehicle-bridge specifications are investigated.

Aerodynamic effects of subgrade-tunnel transition on high-speed railway by wind tunnel tests

  • Zhang, Jingyu;Zhang, Mingjin;Li, Yongle;Fang, Chen
    • Wind and Structures
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    • v.28 no.4
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    • pp.203-213
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    • 2019
  • The topography and geomorphology are complex and changeable in western China, so the railway transition section is common. To investigate the aerodynamic effect of the subgrade-tunnel transition section, including a cutting-tunnel transition section, an embankment-tunnel transition section and two typical scenarios for rail infrastructures, is selected as research objects. In this paper, models of standard cutting, embankment and CRH2 high-speed train with the scale of 1:20 were established in wind tunnel tests. The wind speed profiles above the railway and the aerodynamic forces of the vehicles at different positions along the railway were measured by using Cobra probe and dynamometric balance respectively. The test results show: The influence range of cutting-tunnel transition section is larger than that of the embankment-tunnel transition section, and the maximum impact height exceeds 320mm (corresponding to 6.4m in full scale). The wind speed profile at the railway junction is greatly affected by the tunnel. Under the condition of the double track, the side force coefficient on the leeward side is negative. For embankment-tunnel transition section, the lift force coefficient of the vehicle is positive which is unsafe for operation when the vehicle is at the railway line junction.