• Title, Summary, Keyword: Rail Stability

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The Study on the Behavior of Curved CWR Track under Thermal Load (곡선부 장대레일 궤도의 거동 특성에 관한 연구)

  • Lee, Won-Gyeong;Sung, Deok-Yong;Kim, Man-Cheol;Park, Yong-Gul
    • Proceedings of the KSR Conference
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    • pp.426-436
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    • 2006
  • The use of the CWR track has increased consistently in the worldwide. Because the use of CWR track not only reduces the track maintenance cost, noise and vibration, but increases the life cycle of track components. Therefore, to increase train speed, improve riding condition and secure running stability, the necessity of study on making CWR is increasing. This study includes the development of a thermal buckling theory in the evaluation of curved track stability. The lateral stability of curved CWR is studied for track buckling prevention through the parameter studies. It studied the lateral buckling of the curved CWR track on the 3-D nonlinear analysis. The parameters include rail size, cant, track curvature.

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Analysis of CWR Track Considering Wheel Loads (열차하중을 고려한 장대레일 궤도 해석)

  • Han, Sang-Yun;Kang, Young-Jong;Han, Teak-Hee;Lim, Nam-Hyoung;Kim, Jung-Hun
    • Proceedings of the KSR Conference
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    • pp.2487-2492
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    • 2011
  • At high rail temperature above the neutral temperature, high compressive axial stresses will occur in the rails. High thermal axial force and vehicle loads cause the track to shift in a lateral direction and the formation of track geometry imperfections (track irregularity). When the thermal stress level and track irregularity with vehicle load reach a critical value, the track loses stability. In many studies, the stability of CWR tracks is analyzed. However these studies are only considered in temperature load. The main objective of this investigation was to estimate a new, comprehensive, realistic, the stability of CWR tracks considering wheel load. The ballast resistance is changed by wheel load. When the wheel load is applied, rails and ties are moved upward or downward. In this case the friction between ties and ballasts is decreased or increased. In this study the change of the ballast resistance of each tie was applied to the nonlinear analysis of CWR tracks.

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The Running Test of the Developed Bogie on the Roller Rig for Korean High Speed Train (한국형 고속전철용 개발대차의 주행시험대에서 주행성능평가)

  • 정훈;김진태
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • pp.218-221
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    • 2004
  • This Research is to test the running stability of the developed bogie with 350km/h of which conventional speed is faster than Korea TGV 300Km/h. The running stability test has been executed in status of a car with the developed bogie on the roller rigger to adjust similar to the actual condition. And the test has been done in the two rail conditions, i.e. excitation and non-excitation, respectively. Running speed of bogie increased by the roller step by step. In consequence, the developed bogie in the non-excitation has run without any unstable point for 400kn0h. Vibration characteristics of carbody also was within the value specified on the UIC 518.

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Shape Optimization for a Jaw Using Design Of Experiments (실험계획법을 이용한 조(Jaw)의 형상최적설계)

  • Bang, Il-Kwon;Kang, Dong-Hun;Han, Dong-Seop;Han, Geun-Jo;Lee, Kwon-Hee
    • Journal of Navigation and Port Research
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    • v.30 no.8
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    • pp.685-690
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    • 2006
  • The rail clamp is the device to prevent that a crane slips along rails due to the wind blast as well as to locate the crane in the set position for loading and unloading containers. The wedge typed rail clamp should be designed to consider the structural stability and the durability because it compresses both rail side with large clamping force by the wedge working as the wind speed increases. In this research, the design of experiments(DOE) and the variation technology(VT) built in ANSYS WORKBENCH are utilized to determine the optimum shape of a jaw. The optimum results obtained by two methods are compared and examined.

Analytical and Experimental Study on the Quality Stability of Multi Roll Forming Process (멀티 롤 포밍 공정의 품질 안정성에 대한 해석 및 실험적 연구)

  • Son, Jae-Hwan;Han, Chang-Woo;Ryu, Kyung-Jin;Kang, Hae-Dong;Kim, Chul-Hong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.16 no.10
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    • pp.6977-6984
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    • 2015
  • It is faced with the necessity of multi roll forming process of the ball slide rail which is made by adding the separate manufacturing processes, piercing, bending, trimming, to the roll forming process of a continuous plastic deformation, to improve the quality. However, the vibration and noise of the press machine in this process leads to the quality degradation of slide rail manufactured in this process. In this study, the roll was designed considering the optimal strain rates by the roll forming program with finite element method. And to estimate the static stability of the multi process the Von-Mises stress and deformation on the press was calculated with a structural analysis program. Also, to avoid driving systems in the resonance region their natural frequencies in the 1st and 2nd mode were calculated through the modal analysis. To verify its dynamic stability improvement the magnitudes of noise and vibration in the existing and studied system were compared using a microphone and accelerometers. And the widths and surface roughnesses of the rails which had been produced in the existing and studied process were measured. Therefore, it is known that multi roll forming process is stable in the analytical and experimental study.

Stochastic stability control analysis of an inclined stay cable under random and periodic support motion excitations

  • Ying, Z.G.;Ni, Y.Q.;Duan, Y.F.
    • Smart Structures and Systems
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    • v.23 no.6
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    • pp.641-651
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    • 2019
  • The stochastic stability control of the parameter-excited vibration of an inclined stay cable with multiple modes coupling under random and periodic combined support disturbances is studied by using the direct eigenvalue analysis approach based on the response moment stability, Floquet theorem, Fourier series and matrix eigenvalue analysis. The differential equation with time-varying parameters for the transverse vibration of the inclined cable with control under random and deterministic support disturbances is derived and converted into the randomly and deterministically parameter-excited multi-degree-of-freedom vibration equations. As the stochastic stability of the parameter-excited vibration is mainly determined by the characteristics of perturbation moment, the differential equation with only deterministic parameters for the perturbation second moment is derived based on the $It{\hat{o}}$ stochastic differential rule. The stochastically and deterministically parameter-excited vibration stability is then determined by the deterministic parameter-varying response moment stability. Based on the Floquet theorem, expanding the periodic parameters of the perturbation moment equation and the periodic component of the characteristic perturbation moment expression into the Fourier series yields the eigenvalue equation which determines the perturbation moment behavior. Thus the stochastic stability of the parameter-excited cable vibration under the random and periodic combined support disturbances is determined directly by the matrix eigenvalues. The direct eigenvalue analysis approach is applicable to the stochastic stability of the control cable with multiple modes coupling under various periodic and/or random support disturbances. Numerical results illustrate that the multiple cable modes need to be considered for the stochastic stability of the parameter-excited cable vibration under the random and periodic support disturbances, and the increase of the control damping rather than control stiffness can greatly enhance the stochastic stability of the parameter-excited cable vibration including the frequency width increase of the periodic disturbance and the critical value increase of the random disturbance amplitude.

Evaluation of Behavior of Direct Fixation Track and Track Girder Ends on Yeongjong Grand Bridge (영종대교 강직결 궤도 및 종형거더 단부의 거동 분석)

  • Choi, Jung-Youl;Chung, Jee-Seung;Kim, Jun-Hyung;Lee, Kyu-Yong;Lee, Sun-Gil
    • Journal of the Korean Society of Safety
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    • v.31 no.6
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    • pp.45-51
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    • 2016
  • The purpose of this study is to investigate the influence of train-induced end rotation of simple supported track girder on the performance of a direct fixation track system (DFTS) in Yeongjong grand bridge. In this study, the influences of deflection of a DFTS and track girder on dynamic rail-track girder interaction forces for the track girder ends currently employed in airport express lines were assessed by performing field tests using actual vehicles running along the service lines. Therefore, the dynamic displacement of rail and track girder and the fastener stress on the center and ends sections of DFTS were measured for two different trains (AREX and KTX) running in Yeongjong grand bridge. A three-dimensional finite element analysis (FEA) model using the time-history function based on the design wheel load was used to predict the train-induced track and track girder displacement, and the FEA and field test results were compared. The analytical results reproduced the experimental results well within about 3-7% difference in the values. Therefore, the FEA model of DFTS on track girder is considered to provide sufficiently reliable FEA results in the investigation of the behavior of DFTS. Using the analytical and experimental results, the influence of train-induced end rotation of simple supported track girder on the interaction behavior of rail and track girder installed on a simple supported track girder ends, i.e., upward displacement of rail-track girder and the fastener stress, was investigated. It was found that the train-induced end rotation effect of track girder was not significantly affected by the upward displacement of rails and the fastener stresses of track girder ends. Further, the interaction behavior of rail and track girder were similar to or less than that of the general railway bridge deck ends, nevertheless the vertical displacement of track was higher than that of conventional DFTS on the general railway bridge. From the results, the dynamic responses of the DFTS on track girder ends were not significantly affected by the safety and stability of DFTS ends.

Brake Lining Can be Applied to Super High Speed Vehicle

  • Nakano, Satoru;Maejima, Takashi
    • Proceedings of the Korean Powder Metallurgy Institute Conference
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    • pp.1305-1306
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    • 2006
  • A new material was developed to achieve improvement of heat durability, improvement of wear resistance, stability of friction coefficient and reduction in aggression to counterpart, because it is difficult to maintain braking properties by using currently available materials in the train wagons used for high-speed transportation. As a result, the new material showed a stable wear resistance even in the speed range of 350km/h, where improvement was also confirmed in reduction of aggression to counterpart material by more than approximately 10%. This development was adopted for the brake lining in the Taiwan High Speed Rail project.

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Geological origin and Structural characteristics of Faults (단층의 지질학적 성인과 구조지질학적 특성)

  • Yoon, Woon-Sang;Rim, Hyoung-Gyu;Jeong, Ui-Jin
    • Proceedings of the Korean Geotechical Society Conference
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    • pp.138-146
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    • 2007
  • The 'Fault' has been common interests to the structural geologists, geotechnical engineers and civil engineers. The 'Fault' is very important factor to evaluate to the geotechnical stability. In this paper, geological origin and classification of faults with structural geological features are described. These geological characteristics of faults are useful to understand and detect of faults for engineering practice.

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A Running Stability Test of 1/5 Scaled Bogie using Small-Scaled Derailment Simulator (소형탈선시뮬레이터를 이용한 1/5 축소대차의 주행안정성 시험)

  • Eom, Beom-Gyu;Kang, Bu-Byoung;Lee, Hi-Sung
    • Journal of the Korean Society for Railway
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    • v.15 no.1
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    • pp.9-16
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    • 2012
  • The dynamic stability of railway vehicle has been one of the important issues in railway safety. The dynamic simulator has been used in the study about the dynamic stability of railway vehicle and wheel/rail interface optimization. Especially, a small scale simulator has been widely used in the fundamental study in the laboratory instead of full scale roller rig which is not cost effective and inconvenient to achieve diverse design parameters. But the technique for the design of the small scale simulator about the dynamic characteristics of the wheel-rail system and the bogie system has not been well developed in Korea. Therefore, the research using the small-scaled derailment simulator and the 1/5 scaled bogie has been conducted. In this paper, we did running stability test of 1/5 scaled bogie using small-scaled derailment simulator. Also, for the operation of the small scaled simulator, it is required to investigate the performance and characteristics of the simulator system. This could be achieved by a comparative study between an analysis and an experiment. This paper presented the analytical model which could be used for verifying the test results and understanding of the physical behavior of the dynamic system comprising the small- scaled derailment simulator and the 1/5 scaled bogie.