• Title/Summary/Keyword: Wheel Impact Test

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The Evaluation of Track Impact Factor on the Various Track Type in Urban Transit (도시철도 궤도구조별 궤도충격계수 평가)

  • Choi, Jung-Youl;Park, Yong-Gul;Lee, Sang-Min
    • Journal of the Korean Society for Railway
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    • v.14 no.3
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    • pp.248-255
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    • 2011
  • Impact factor of concrete and ballast track which has been used in Korea railway was applied to equation (1+0.513V/100) from AREA. As the use of this equation, overcapacity of track design might be occurred. Therefore, this study compared impact of ballast track (well, bad) and concrete track (sleeper embeded system, rail floating and sleeper floating) by field test to analyzing dynamic effect of track structure's characterstic and wheel load on service line. In addition, it suggested a method to generate reasonable impact factor on each track type.

Characteristics of Curved Track Behaviors according to Traveling Tilting Train (틸팅차량 주행에 따른 기존선 곡선 궤도의 거동 특성)

  • Park, Yong-Gul;Choi, Jung-Youl;Sung, Deok-Yong;Chun, Dae-Sung
    • Journal of the Korean Society for Railway
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    • v.10 no.6
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    • pp.692-700
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    • 2007
  • A trial run of locally-developed tilting train has been in process on Chungbuk line since the test vehicle was first produced. For the system stabilization, interface verification among the systems including track, structure, catenary and signaling system, not to mention the rolling stock, is very crucial. In the area of wayside structure, the stability of track structure and train run shall be evaluated through the review of impact by increased speed by developed train on track structure. The study thus was intended to evaluate the impact on track while a tilting train is running the curve section, which is vulnerable to accelerated train speed. The analysis of tilting train test running the part of Chungbuk line and Honam line was conducted to identify the impact on existing track performance by tilting train. To identify the movement behavior of each part of track while tilting train, high speed train and traditional train (Mugunghwa and freight train) were running the existing line, wheel load, lateral wheel load, rail bending stress, vertical and lateral displacement of rail and vertical displacement of sleeper were compared and analyzed so as to evaluate the expected impact by tilting train for improving the train speed.

Analysis for Optimal Rail Grinding Amount by Rolling Contact Fatigue Test in High Speed Railway (구름접촉피로시험을 통한 고속철도 레일연마량 분석)

  • Chang, Ki-Sung;Sung, Deok-Yong;Park, Yong-Gul;Choi, Jin-Yu;Lee, Dong-Hyung
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.2115-2124
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    • 2011
  • The rail surface defects which are generated on repeated rolling contact fatigue are getting increased according to high speed, high density, and minimum weight. In addition, Increasing noise and vibration are affected by these also impact load generated as well. Because of this phenomenon, more serious and critical damages were occurred. In fact, in order to control them, the rail grinding were conducted. However, there are not enough researches to make an criteria of generating optimal rail grinding amount in Korea. This study evaluated how depth of hardening on rail surface is formed and suggested optimal rail grinding amount by RCF(rolling contact fatigue) test with generated contact pressure between KTX wheel and UIC60 rail by applying FEM analysis. Therefore, the amount was generated approximately 0.2mm/20MGT to maintain integrity of rail surface by getting rid of depth of hardening on rail according to rail accumulated passing tonnage.

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Reliability Assessment of Tubular Markers Used for Road Safety Facilities (도로안전시설용 시선유도봉의 신뢰성 평가)

  • Koo, Hyun-Jin;Yoon, Ye-Seok
    • Journal of Applied Reliability
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    • v.12 no.2
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    • pp.91-103
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    • 2012
  • Tubular markers for road safety facilities are used to lead the driver's sight line and separate the lanes on the road. Such tubular markers are usually installed on the road and frequently hit by vehicles, they are accordingly requested to assure the product durability. The traditional evaluation method of tubular markers include only quality tests of the material properties. However, most of consuming agencies in charge of road management at fields have proposed problems on long-term performance of the products hit by vehicles under various weather conditions. Therefore, the objectives of this study are to develop the reliability test methods and equipments to simulate the product failures of tubular markers due to vehicle collision and wheel compression and the delamination and discoloration of reflection sheets attached on the surface of the products under high and low temperatures.

Analytical Behavior of Concrete Derailment Containment Provision(DCP) according to Train Impact Loading (열차 충돌하중에 대한 콘크리트 일탈방호시설물(DCP)의 해석적 거동 검토)

  • Yi, Na-Hyun;Kim, Ji-Hwan;Kang, Yun-Suk
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.11
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    • pp.604-613
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    • 2018
  • In recent years, numerous train derailment accidents caused by deterioration and high speed technology of railways have increased. Guardrails or barriers of railway bridges are installed to restrain and prevent the derailment of the train body level. On the other hand, it can result in a high casualties and secondary damage. Therefore, a Derailment Containment Provision (DCP) within the track at the wheel/bogie level was developed. DCP is designed for rapid installation because it reduces the impact load on the barrier and inertia force on the steep curve to minimize turnover, fall, and trespass on the other side track of the bridge. In this paper, DCP was analyzed using LS-Dyna with a parameter study as the impact loading location and interface contact condition. The contact conditions were analyzed using the Tiebreak contact simulating breakage of material properties and Perfect bond contact assuming fully attached. As a result, the Tiebreak contact behaved similarly with the actual behavior. In addition, the maximum displacement and flexural failure was generated on the interface and DCP center, respectively. The impact analysis was carried out in advance to confirm the DCP design due to the difficulties of performing the actual impact test, and it could change the DCP anchor design as the analysis results.

Study on the Behavior of Curved Track in Honam High-Speed Line considering the Running Performanace for HEMU 430-X (HEMU 430-X 주행특성을 고려한 호남고속철도 곡선궤도구조의 거동연구)

  • Kang, Yun-Suk;Um, Ki-Young;Kim, Seog-Won
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.4068-4076
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    • 2013
  • The wheel-rail interaction forces are influenced by the velocity of vehicle, wheel load, alignment (curve radius, cant etc). For the safety of track structure, it is required to evaluate the influences for track and influential factors. Recently, the HEMU 430-X, which was developed by Next Generation High-Speed Rail Development R&D Project, achieved 421.4km/h in a test run of Daegu.Busan section of the Gyeongbu high speed rail on March in 2013. In the case of additional speed-up test on Test-Bed Section(Gongju.Jeongeup: KP 100~128km Osong starting point), the analysis of track forces is required for outer rail by the increase of dynamic force and centrifugal force of vehicle. In this paper, the vehicle speed variation on HSL line is evaluated by TPS analysis considering the tractive effort of HEMU 430-X, tested running resistance and alignment of Honam HSR. And the track forces are evaluated by centrifugal force and impact factor on curved track.

Comparison of the Fatigue Behaviors of FRP Bridge Decks and Reinforced Concrete Conventional Decks Under Extreme Environmental Conditions

  • Kwon, Soon-Chul;Piyush K. Dutta;Kim, Yun-Hae;Anido, Roberto-Lopez
    • Journal of Mechanical Science and Technology
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    • v.17 no.1
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    • pp.1-10
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    • 2003
  • This paper summarizes the results of the fatigue test of four composite bridge decks in extreme temperatures (-30$^{\circ}C$ and 50$^{\circ}C$ ). The work was performed as part of a research program to evaluate and install multiple FRP bridge deck systems in Dayton, Ohio. A two-span continuous concrete deck was also built on three steel girders for the benchmark tests. Simulated wheel loads were applied simultaneously at two points by two servo-controlled hydraulic actuators specially designed and fabricated to perform under extreme temperatures. Each deck was initially subjected to one million wheel load cycles at low temperature and another one million cycles at high temperature. The results presented in this paper correspond to the fatigue response of each deck for four million load cycles at low temperature and another four million cycles at high temperature. Thus, the deck was subjected to a total of ten million cycles. Quasi-static load-deflection and load-strain responses were determined at predetermined fatigue cycle levels. Except for the progressive reduction in stiffness, no significant distress was observed in any of the composite deck prototypes during ten million load cycles. The effects of extreme temperatures and accumulated load cycles on the load-deflection and load-strain response of FRP composite and FRP-concrete hybrid bridge decks are discussed based on the experimental results.

A Study on Stability Assessment of Vehicle and Track on Transition between Conventional and Zero-Longitudinal Resistance Rail Fastener (일반체결구/활동체결구 접속구간 차량 및 궤도 안정성 평가에 관한 연구)

  • Yang, Sin-Chu;Jang, Seung-Yup;Yoo, Eun;Kim, Jin-Young;Hong, Sung-Mo
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.1078-1083
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    • 2008
  • In this paper, assessed are the stability of vehicle and track according to vertical support stiffness difference on the transition between conventional and zero-longitudinal resistance (ZLR) rail fastener on bridge. For this, the spring constants of rail fastener have been determined according to different load ranges - KTX load (with or without impact factor) and test load of EN standards - from results of laboratory test on rail pad, the stability analysis of vehicle and track has been performed according to numbers or installation length of ZLR fasteners using vertical vehicle-track coupled model to consider train-track interaction. The analysis results reveal that only the wheel load variation slightly exceed the limit value when 2 ZLR fasteners are used with spring constant determined within the EN test load range, but, in all other cases, all evaluation items are satisfied. Thus, it can be said that the stability of vehicle and track will not be degraded by ZLR fastener.

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Attitude analysis induced by the disturbances on COMS using the received telemetries during normal mode (정상모드에서 수신된 텔레메트리를 이용한 외란에 의한 천리안위성 자세영향 분석)

  • Park, Young-Woong;Park, Bong-Kyu
    • Aerospace Engineering and Technology
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    • v.11 no.1
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    • pp.27-41
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    • 2012
  • In this paper, there is analyzed the disturbances to impact on COMS attitude and the attitude error using the received telemetries in KARI ground station during normal mode of COMS. COMS was launched successfully at Kourou, French Guiana on the 26th of June, 2010. Up to now after IOT(in-orbit test), COMS is performing well the main mission to measure meteorology and ocean during about half and one year. The disturbances to impact on COMS attitude are mostly by the Sun, by the motion of payload mirror and by the spike happened during operation of earth sensor mirror and wheel. The analysis result on the other cases happened rarely during the nominal operation, is summarized.

Effects of Mechanical Properties on Wear Resistance of 0.27C-0.70Ni-1.42Cr-0.20Mo Steel (0.27C-0.70Ni-1.42Cr-0.20Mo 내마모강의 기계적 성질에 따른 마모특성)

  • Lee Y. H.;Han C. H.;Shin J. H.;Jang B. L.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2001.10a
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    • pp.260-263
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    • 2001
  • Mechanical properties have been accepted to be major factor to improve wear resistance. The effect of mechanical properties on wear resistance of 0.27C-0.70Ni-1.42Cr-0.20Mo steel was studied under various test conditions. It is clear that yield strength, tensile strength, impact value, and hardness are strongly related each other. Wear resistance tests as pin on plate type and dry sand / rubber wheel type proved to be that wear depends on mechanical properties. Microstructures were also observed to make clear the wear properties. At quenching and low temperature tempering, the specimen has a good wear resistance.

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