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REFERENCE LINKING PLATFORM OF KOREA S&T JOURNALS
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Journal of the Korean society for railway
Journal Basic Information
Journal DOI :
Korean Society for Railway
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Volume & Issues
Volume 15, Issue 6 - Dec 2012
Volume 15, Issue 5 - Oct 2012
Volume 15, Issue 4 - Aug 2012
Volume 15, Issue 3 - Jun 2012
Volume 15, Issue 2 - Apr 2012
Volume 15, Issue 1 - Feb 2012
Selecting the target year
Impact Test for Measurement of the Carbody Bending Modes of Railway Vehicle
Shin, Bum-Sik ; Choi, Yeon-Sun ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 423~428
DOI : 10.7782/JKSR.2012.15.5.423
As the speed of high speed train increases, the prediction of ride comfort becomes important. The exciting frequencies due to rail irregularity in high-speed train closes to the second and third natural frequencies of the carbody. The dynamic characteristics of railway vehicles should be checked by modal analysis numerically and experimentally. In this study the bending test for railway vehicle is reviewed and the impact test is suggested to find the natural frequencies and the mode shapes of the carbody. The validity of the impact test is checked with the test for a sample plate which reflects the aspect ratio of the original carbody. The bending test by the impact and the displacement methods of JIS E7105 for a prototype carbody were done in the field and compared. The results show that the impact test can find more accurate natural frequencies and the mode shapes of the carbody than those of the displacement method.
A Study on the Estimation and Improvement of the Current Collection Performance for the Next Generation High-Speed Train (HEMU-430X)
Lee, Jin-Hee ; Park, Tae-Won ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 429~435
DOI : 10.7782/JKSR.2012.15.5.429
The HEMU-430X is a world-class railway vehicle which aimed the maximum speed of 430km/h and the operation speed of 370km/h. To maintain high-speed operation condition over 300km/h, various requirements for satisfy exist. However, one of the most important things is a reliable supply of electricity. Especially, the dynamic interaction between the pantograph and overhead contact line at high-speed is a significant matter to pre-evaluate. In this paper, using the dynamic interaction analysis program, current collection performance of the HEMU-430X was investigated. Firstly, based on the international standard, performance of the original specifications was evaluated. In addition, through study on changes in tension and span length, improvement of the performance was considered.
Characteristics Method Analysis of Wind Pressure of Train Running in Tunnel
Nam, Seong-Won ; Kwon, Hyeok-Bin ; Yun, Su-Hwan ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 436~441
DOI : 10.7782/JKSR.2012.15.5.436
Pressure waves are generated and propagate in tunnel when train enters a tunnel with high speed. Compression wave due to the entry of train head propagates along the tunnel and is reflected at tunnel exit as expansion wave. While expansion wave due to the entry of train tail propagates along the tunnel and is reflected at tunnel exit as compression wave. These pressure waves are repeatedly propagated and reflected at tunnel entrance and exit. Severe pressure change per second causes ear-discomfort for passengers in cabin and micro pressure wave around tunnel exit. It is necessary to analyze the transient pressure phenomena in tunnel qualitatively and quantitatively, because pressure change rate is considered as one of major design parameters for an optimal tunnel cross sectional area and the repeated fatigue force on car body. In this study, we developed the characteristics method analysis based on fixed mesh system and compared with the results of real train test. The results of simulation agreed with that of experiment.
A Study on the Development of Practical Systems Engineering Management Plan Template Using the Systems & Software Engineering Infra
Byun, Bo Suk ; Choi, Yo Chul ; Park, Young Taek ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 442~446
DOI : 10.7782/JKSR.2012.15.5.442
This paper is a practical study on the development of SEMP template using SE & SW infrastructures. SEMP, which is a management system for systems engineers, has been developed for the LRT(Light Rail Transit) industry and has been tailored to suit domestic conditions. SE & SW infrastructures were developed to assist in creating an effective and efficient SEMP for the industry of this study. This paper proposes a method to reduce costs, manpower, and time for the LRT industry using SEMP based on SE & SW infrastructures.
A Study on the Geometry Change for the Increased Contact Wire Tension in the Pre-sagged Existing Catenary
An, Seung-Hwa ; Kim, Yoon-Ho ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 447~453
DOI : 10.7782/JKSR.2012.15.5.447
It is studied that the structure of the contact plane geometry of the contact wire would be changed when the contact wire tension is increased in the existing overhead contact lines for the purpose of improving the operation speed temporarily. In this paper, the dropper length formula which could be well applied to the pre-sagged catenary is reviewed first. Second, the changing amount of the pre-sag if the contact wire tension change from 20kN to 23kN or from 20kN to 25kN for the Gyeongbu HSL(high speed line) 49.5m catenary is evaluated by using of the self-written program in accordance with the dropper length formula. Moreover, the increasing tension and measuring the pre-sag change experiment in the Gyeongbu 2 HSL was conducted. The calculated data are compared with the measured data. As a result, it is found that the geometry change is very little and will not make the current collection performance deteriorated.
Performance Analysis on the Impact of Mutual Interference and the Interference Suppression Method for CBTC System in the Presence of WPAN System
Kim, Seong Cheol ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 454~458
DOI : 10.7782/JKSR.2012.15.5.454
The CBTC(Communication based Train Control) and WPAN(Wireless Personal Area Network) systems employed on 2.4GHz ISM band wireless networks provide complementary service within the same environment. Coexistence between the networks will be impaired if the mutual packets are uncertainty associated the timing or gaussian distance. This paper analyzes the impact of the mutual interference and proposed method to minimize the effect of the WPAN system signals on CBTC system. The performance analysis is illustrated by examining the symbol error rate versus signal to noise interference ratio in terms of carrier frequency offset. The method contributes to reduce the symbol error rate drastically. However it can't be a fundamental solution for the impact on the interference problem. It may be needed for railway only frequency after checking the problems of the current railway frequency.
Development Strategies and Feasibility Evaluation of Maintenance Operation System for Railway Bridge Based on Ubiquitous-BIM Technology
Moon, Hyoun-Seok ; Kim, Hyeon-Seung ; Kang, Leen-Seok ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 459~466
DOI : 10.7782/JKSR.2012.15.5.459
Due to the issues such as omission of data, document based management, maintenance based on measurement data and wire-based network, it is difficult existing maintenance system for railway bridges to act to diverse characteristics of site and environmental changes in real time. With these reasons, there are many constraints in establishing active maintenance strategies for railway bridges. To solve these issues, this study suggests an integrated maintenance business model based on practical utilization and information management based on BIM technology to build a smart maintenance operation system based on ubiquitous computing for railway bridges. To secure its development and practical applications, a quantitative evaluation by questionnaire analysis was performed. Therefore, it is expected that the suggested model will be utilized as a framework model in order to build the smart maintenance operation system from collection of maintenance data to action for railway bridges.
Behavior Characteristics of Railway Roadbed Retained by Geosynthetic Reinforced Segmental Wall Under Train Load
Lee, Seong Hyeok ; Choi, Chan Yong ; Lee, Jin Wook ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 467~475
DOI : 10.7782/JKSR.2012.15.5.467
Static and dynamic train load tests were conducted to evaluate the train load transfer mechanism in the roadbed which was retained by two types (fully and partially) of segmental retaining walls reinforced by geogrid. The test roadbed was 2.6m high, 5m wide, and 6m long. A combination of earth pressure gages, displacement transducers, and strain gages were placed in specific locations to measure the responses. Test results showed that the wall displacement pattern as well as the earth pressure for the fully reinforced retaining wall was different from those for the partially reinforced retaining wall. In the dynamic train load test, the strain in the upper part of the wall tended to decrease, and both the residual deformation and the rate of the deformation were significantly lower than those in the current design standard.
Evaluation of Dynamic Properties of Crushed Stones Used as Reinforced Trackbed Foundation Materials Using Midsize Resonant Column Test apparatus
Lim, Yujin ; Lee, SeongHyeok ; Lee, Jinwoog ; Cho, Hojin ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 476~484
DOI : 10.7782/JKSR.2012.15.5.476
In this study, a mid-size RC test apparatus equipped with analyzing program is developed that can test samples up to D=10cm diameter and H=20cm height which is larger than usual samples of D=5cm and H=10cm used mostly in practice. Thus, crushed stones with larger grains up to 38mm in diameter used mostly in Korea as reinforced trackbed materials in track construction could be considered effectively than conventionally used RC apparatus for evaluation of the dynamic properties of the materials by using the newly developed RC apparatus. The RC test apparatus was designed and assembled based on the concept of fixed-free fixity conditions and driving mechanism proposed by Stokoe. Using the developed RC test apparatus, three types of representative crushed reinforced trackbed materials were tested in order to get the dynamic properties of the materials such as
reduction curves and damping ratio D. For comparison purpose, a small RC test apparatus has been used to test the same materials.
Static and Dynamic Behavior at Low-Frequency Range of Floating Slab Track Discretely Supported by Rubber Mounts in Real-Scale Laboratory Test
Hwang, Sung Ho ; Jang, Seung Yup ; Kim, Eun ; Park, Jin Chul ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 485~497
DOI : 10.7782/JKSR.2012.15.5.485
Recently, with increasing social interests on noise and vibration induced by railway traffic, the application of floating slab track that can efficiently reduce the railway vibration is increasing. In this study, to more accurately understand the dynamic behavior of the floating slab track, a laboratory mock-up test has been performed, and the static and dynamic behaviors at frequency range near the system resonance frequency were explored. Based on the test results, the design of the floating slab track and the structural analysis model used in the design have been verified. The analytic and test results demonstrate that the dominant frequency of the floating slab track occurs at the frequencies between vertical rigid body mode natural frequency and bending mode natural frequency, and the dominant deformation mode is close to the bending mode. This suggests that in the design of the floating slab track, the bending rigidity of the slab and the boundary conditions at slab joints and slab ends should be taken into consideration. Also, the analytic results by the two-dimensional finite element analysis model using Kelvin-Voigt model, such as static and dynamic deflections and force transmissibility, are found in good agreement with the test results, and thus the model used in this study has shown the reliability suitable to be utilized in the design of the floating slab track.
Dynamic Characteristics of Simply Supported Single Span Bridges for KTX and HEMU using Design Diagram
Cho, Jeong-Rae ; Cho, Keunhee ; Kwark, Jong-Won ; Kim, Young Jin ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 498~507
DOI : 10.7782/JKSR.2012.15.5.498
This paper presents the ERRI design diagrams of KTX and HEMU applicable to simply supported single span bridges, and analyzes the dynamic characteristics and design considerations of the bridges under KTX and HEMU using the diagrams. The design diagrams of KTX and HEMU are calculated for the bridges with 25m, 30m, 35m and 40m span lengths, which are widely used for simple bridge in Korea. From the design diagrams, the dynamic characteristics of the bridges with the selected span lengths are analyzed. In addition, the design consideration is discussed to satisfy the design requirement of acceleration. It is desirable for the bridge with 25m span length to avoid resonance both for KTX and HEMU. Since larger responses are expected for HEMU in the bridge with 30m span length, and for KTX in the bridge with 35m and 40m span length, the bridges should be planned to have enough mass satifying acceleration requirement at resonance, or to avoid the resonance.
Estimation of the Life-span for Urban Rolling Stock through LCC Analysis (Focused on Seoul Metro)
Chung, Su Young ; Lee, Won Young ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 508~516
DOI : 10.7782/JKSR.2012.15.5.508
The lifespan of a rolling stock is limited to 25 years by the urban railway law. But it can be extended to 40 years by conducting the regular safety test. This gives additional 15 years of lifespan. In Seoul Metro, Many of the rolling stocks were already replaced with new types in 1996 and 2008. New type - VVVF rolling stocks have better safety, maintainability, durability than old types. For this reason, it is desirable to extend the lifespan of new type-rolling stocks. In this paper, we investigated the economical lifespan using LCC (Life Cycle Cost) analysis. This study shows that the economical lifespan comes out 41 years when extra 10% cost has been considered after 25 years of the train service and 46 years when extra 10% cost not considered.
A Study on the Fare Elasticities of DST Applications; An Empirical Analysis
Yun, Donghee ; Lee, Jinsun ; Kim, Ickhee ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 517~523
DOI : 10.7782/JKSR.2012.15.5.517
Double Stack Train(DST) is being used variously around USA and Canada. The greatest advantage of the DST is mass transportation without extending the length of freight train and number of cars. So the DST system can be a kind of innovative train to increase the competitiveness of rail logistic business. As the domestic rail logistic increase, for enhancement of environment friendly green transportation amount, the DST needs more for efficiency. In this study, as the alternative way to introduce the DST to the Kyungbu Line, it's investigated the extensibility of rail freight with the relation of rail fare discount and examined the necessity of pilot business to the Kyungjeon Line which was expected comparatively lower cost. If the DST system is introduced to the Kyungjeon Line, the cost of mass transportation can be much lower and then the comparativeness of rail transportation will be increased, therefore logistic companies can have some margin additionally. In the result of survey to the related companies, if rail transportation fare is 37.7 % cheaper than current road transportation fare, the modal shift can be transferred by maximum 100%.
An Optimization Model for Railway Slot Allocation Reflecting the Operational Policies
Park, Bum Hwan ; Hong, Soon-Heum ; Kim, Chung-Soo ;
Journal of the Korean society for railway, volume 15, issue 5, 2012, Pages 524~530
DOI : 10.7782/JKSR.2012.15.5.524
Recently, open access policy to railway operation has been widely discussed. Compared to the case of Korea, European countries have dealt with this topic over a few decades. The competition on railway slots incurs an important technological problem about how to optimally allocate railway slots requested from RUs to them. In other words, the authority should be able to coordinate the timetables requested from RUs in the non-discriminatory manner. Related with the coordination, compared to the other European countries, which have done many studies and experiments especially on auction mechanisms, Korean railway has paid less attention to this topic and there have not been any related studies. Our study analyses the state-of-the-arts about the railway slot allocation especially focusing on the auction mechanisms and the associated optimization problems. And we suggest a new railway slot allocation mechanism and related optimization model reflecting the adjustment within the tolerance and the operational policies between railway undertakings.