• Title, Summary, Keyword: 철도차량 동역학

Search Result 89, Processing Time 0.04 seconds

Prediction of Optimal Catenary Tension by Dynamic Characteristic Measurement and Dynamic Analysis of Pantograph in High-Speed Train (고속열차 팬터그래프 동특성 측정 및 동역학 해석을 통한 최적 전차선 장력 예측)

  • Oh, Hyuck Keun;Yoo, Geun-Jun;Park, Tae-Won
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.11
    • /
    • pp.350-356
    • /
    • 2018
  • The contact force, which is the dynamic interaction between the pantograph and the catenary, is an important indicator for evaluating the current collecting quality, which is a stable power supply characteristic to the vehicle. In this study, dynamic contact force characteristics of pantograph of HEMU-430X vehicle, which is a power-distributed high-speed train test vehicle, were analyzed according to the catenary tension and compared with the analytical results using the pantograph-catenary interaction model. As a result of comparing the test results with the analytical results, it was confirmed that the average contact force and the standard deviation of the contact force, which are the main dynamic contact force characteristics, coincide relatively well. Using the analytical model, the relationship between the catenary tension and the contact force is presented according to the vehicle speed, and the optimal catenary tension for each operation speed is presented and compared with the international standard. As a result, it was found that the results obtained from the analysis are comparable to those recommended by international standards.

Development of the All-Wheel-Steering Algorithm using Dynamic Analysis of the Bi-modal Vehicle (저상굴절차량의 주행해석을 이용한 전차륜 조향 알고리즘 개발)

  • Jeon, Yong-Ho;Park, Tae-Won;Lee, Soo-Ho;Kim, Duk-Gie;Moon, Kyung-Ho
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.16 no.1
    • /
    • pp.144-151
    • /
    • 2008
  • The bi-modal vehicle is composed of two car-bodies and three axles. Each axle of the vehicle has an independent suspension and all wheels are steerable. Since the bi-modal vehicle has longer wheelbase than most urban buses, the All-Wheel-Steering(AWS) system is adapted for to ensure safe driving and proper turning radius on a curved road. This paper proposes an AWS control algorithm for stable driving of bi-modal vehicle. Steering angles and directions of each axle of bi-modal vehicle changed according to the driving environment and steering modes. In the case that front and rear axles should be steered in opposite directions is a negative mode, and the other case that the axles should be steered in the same direction is a positive mode. For example, in the positive mode, front and real axles are steered in the same direction, while in the negative mode, they are steered in the opposite direction. A multibody model of the vehicle is used to verify the performance of the steering algorithm and simulation results of 2WS are compared with those of AWS under the same condition.

NUMERICAL ANALYSIS FOR THE EFFECT OF BLOOD FLOW RATE AND BIFURCATION ANGLE ON THE LOCATION OF ANTERIOR CIRCULATION ANEURYSM AND THE CHANGE OF BLOOD FLOW CHARACTERISTICS AFTER ANEURYSM FORMATION (전방순환동맥류 발생 위치에 대한 혈류량 및 분지각의 영향 및 동맥류 발생 전후의 유동 변화에 관한 수치해석 연구)

  • Kim, S.Y.;Ro, K.C.;Ryou, H.S.
    • Journal of computational fluids engineering
    • /
    • v.16 no.4
    • /
    • pp.64-71
    • /
    • 2011
  • Cerebral aneurysm mostly occurs at a bifurcation of the circle of Willis. When the cerebral aneurysm is ruptured, a disease like subarachnoid hemorrhage and stroke is caused and this can be even deadly for patients. Generally it is known that causes of the intracranial aneurysm are a congenital deformity of the artery and pressure or shear stress from the blood flow. A blood flow pattern and the geometry of the blood vessel are important factors for the aneurysm formation. Research for several hemodynamic indices has been performed and these indices can be used for the prediction of aneurysm initiation and rupture. Therefore, the numerical analysis was performed for hemodynamic characteristics of the blood flow through the cerebral artery applying the various bifurcation angle and flow rate ratio. We analyze the flow characteristics using indices from the results of the numerical simulation. In addition, to investigate the flow pattern in the aneurysm according to the bifurcation angle and the flow rate ratio, we performed the numerical simulation on the supposition that the aneurysm occurs.

A study on the Vibration Reduction of the Commercial High-speed Train (운영 중인 고속열차의 진동저감에 관한 연구)

  • Jeon, Chang-Sung;Choi, Sunghoon
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.11
    • /
    • pp.697-704
    • /
    • 2017
  • This study was carried out to investigate and alleviate the vibration problem of commercial high-speed trains. First, the measurement of the carbody vibration was performed, in order to determine the vibration level of the high-speed train. The measurement result showed that the vibration level of the driver cab was higher than that of the passenger car and that the vibration became bigger toward the trailing end of the train. The vertical vibration of the driver cab and passenger car was larger than the transverse vibration, and the maximum value of the vibration in the ballast section was larger than that in the concrete section. A dynamic analysis was carried out to improve the vibration of the KTX-Sancheon train. The results of the analysis showed that it is necessary to reduce the vibration of the driver cab and both ends of the passenger cars. To reduce the vibration of the driver cab, it was recommended that the stiffness of the secondary coil spring be reduced and the damping coefficient of the secondary vertical damper be increased. It was found that the failure of the suspension system could be the origin of the vibration problem of the high-speed train. The proper management of wheel wear plays an important role in the improvement of the operation efficiency and reduction of the carbody vibration of high-speed trains, and research is underway to change the present wheel profile to increase the mileage between wheel turning.

A Study on the Ride Quality Enhancement of the High-speed Electric Multiple Unit (동력분산형 고속열차의 승차감 개선에 관한 연구)

  • Jeon, Chang-Sung;Kim, Sang-Soo;Kim, Seog-Won
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.19 no.11
    • /
    • pp.561-567
    • /
    • 2018
  • This study was carried out to improve the ride quality of high-speed electric multiple unit. Through dynamic analysis of the HEMU-430X, the range of the equivalent conicity with a critical speed of 300 km/h was between 0.05 and 0.25. The initial adopted wheel profile of HEMU-430X was S1002. The equivalent conicity of S1002 with the mileage of more than 40,000 km was about 0.033 and it was confirmed that XP55 is more suitable for stable operation because XP55 has the equivalent conicity of over 0.061. In order to improve ride quality of high-speed electric multiple unit, the change of installation angle of the yaw damper was suggested from $7.35^{\circ}$ to $0^{\circ}$. From sensitivity analysis and optimization, the air spring lateral and vertical stiffness was suggested to be reduced by 30% and the secondary vertical and lateral damper damping coefficient was increased by 50%. By applying this, it was expected that the car body acceleration could be improved by about 20% on average. The HEMU-430X's yaw damper installation angle was changed to $0^{\circ}$ and the damping coefficient of the lateral damper was increased by 30%. When the test run was carried out at the speed of 300 km/h on the Kyungbu high-speed line, the vehicle lateral acceleration had improved by 34.3%. The effect of additional improvement measures proposed in this paper will be tested in the on track test. The riding quality improvement process used in this study can be used to solve ride quality problems that can occur in commercial operation of high-speed electric multiple unit in the future.

A Study on the Dynamic Behavior of the High Speed Railway Tracks (고속철도(高速鐵道)의 궤도(軌道)에 대한 동특성(動特性) 연구(研究))

  • Moon, Je Kil;Kang, Kee Dong
    • Journal of The Korean Society of Civil Engineers
    • /
    • v.12 no.1
    • /
    • pp.97-105
    • /
    • 1992
  • The purpose of this study is to provide the cause and countermeasure for track problems in the high speed railways due to the irregularly increasing dynamic wheel loads running over the speed range of 300 km/h. It has long been recognised that the track problems encountered on high speed railways are associated mainly with vertical dynamic loads which are related to the unsprung mass of vehicles and track irregularities. In addition to these parameters for the estimation of the dynamic wheel load variation, however, the dynamic characteristics of track structures are discussed in this paper with reference to mathematical modelling of the tracks and vehicle. From the results of the more detailed analyses, the effects of track stiffness and damping characteristics are considered to be significant for reducing the dynamic wheel loads. To make this point clear and appraise the overall performance of the track components, the theoretical analysis on the dynamic behavior of the tracks and wheel set impact tests on several track structures are performed. The experimental results from different track components are compared with each other. The track stiffness and damping characteristics are also presented quantatively.

  • PDF

A Study on Critical Speed Enhancement of High-speed Train Passenger Car (고속열차 객차의 임계속도 향상에 관한 연구)

  • Jeon, Chang-Sung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.17 no.12
    • /
    • pp.603-610
    • /
    • 2016
  • Over 12 years have passed since the first commercial operation of a Korean high-speed train. Since then, the transport capacity of the high-speed lines has become almost saturated. Therefore, studies have been carried out to increase the operating speed of the trains in order to increase their transportation capacity. This study was carried out to improve the critical speed of the KTX-Sancheon, Korean high-speed train, in order to increase its operating speed. A dynamic analysis of the KTX-Sancheon train was performed using the contact data obtained from the wheel wear profiles that were measured from a KTX-Sancheon train in commercial operation. The analysis results were verified by comparing them with the measurement acceleration data obtained from KTX-Sancheon. The suspension parameters were optimized to improve the operation speed. The critical speed of KTX-Sancheon was increased by 9.4% after the optimization by the response surface method. The optimized suspension parameters are expected to be used for the new bogie design to increase the operating speed of KTX-Sancheon from 300km/h to 350km/h.

Parametric Study on 3-way Switch Design Considering Levitation Stability of Maglev Train (자기부상열차의 부상안정성을 고려한 3방향 분기기의 설계 파라미터 연구)

  • Lee, Younghak;Han, Jong-Boo;Lim, Jaewon;Lee, Jong-Min
    • Journal of the Korean Society for Railway
    • /
    • v.19 no.2
    • /
    • pp.135-144
    • /
    • 2016
  • It is essential to lighten the weight of switch girders in order to reduce their costs of manufacturing and make it easier to use them in construction. Lightening the weight of switch is also important to the Maglev 3-way switches system, however, the design variables should be considered very carefully if lightening is to be applied to the system, because these variables are vitally related to the levitation stability. Because Urban Maglev trains have a structure in which train bogie wraps around the guiderail, the adjustment of a girder's height is a possible way to reduce the weight. The safety of the application of this concept is ensured by repeated experiments in a test bed, however, due to a lack of space and budget limits, the design parametric study for the system model can substitute for actual application. The purpose of this paper is to study the design parameters that are concerned with levitation stability while a Maglev train is running on the Maglev 3-way system depending on the weight of the switch girders. In this study, switch girder weight is reduced by adjustment of girder height and girders are and modeled as a flexible body. The effect of the adjustment of girder height on the levitation stability can be analyzed by comparing the velocity of the train when it passes the switch girders, with the lateral gap, and the levitation gap which are obtained from the co-simulation of the Maglev train's dynamics model and flexible switching system. The results of this research will be used to design a Maglev switch.

Evaluation of Running Performance of the Composite Bogie under Different Side Beam Stiffness (사이드 빔 강성에 따른 복합소재 대차의 주행성능 평가)

  • Kim, Jung-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.4
    • /
    • pp.86-92
    • /
    • 2017
  • In this study, a running performance evaluation and roller rig test was conducted to evaluate the applicability of a composite bogie frame, which has the role of the primary suspension. The composite bogie frame was made of a GEP224 glass/epoxy prepreg. Vehicle dynamic analysis was carried out on the composite bogie with three different kinds of side beam thicknesses (50 mm, 80 mm, and 150 mm). From the results, the composite bogie with a side beam thickness of 80 mm satisfied all the dynamic design requirements. Although the composite bogie with the side beam thickness of 50mm also met the design requirements, its critical speed was just a 2% margin to the requirement. In contrast, the model of the side beam thickness of 150mm did not meet the ride comfort. In addition, a composite bogie frame with the side beam thickness of 80 mm was fabricated and installed on a complete bogie. Moreover, the roller rig test using the fully equipped bogie was performed to evaluate the critical speed. During the test, the lateral excitation was imposed on the wheelsets to realize the rail irregularity. There was no divergence of the lateral displacement of the wheelsets while increasing the speed. The measured critical speed was similar to the predicted result.