• Title/Summary/Keyword: Wheel-climbing Derailment

Search Result 6, Processing Time 0.021 seconds

Development of a Theoretical Wheelset Model to Predict Wheel-climbing Derailment Behaviors Caused by Rolling Stock Collision (철도차량 충돌에 의한 타고오름 탈선거동 예측을 위한 단일윤축 이론모델 개발)

  • Choi, Se-Young;Koo, Jeong-Seo;You, Won-Hee
    • Journal of the Korean Society for Railway
    • /
    • v.14 no.3
    • /
    • pp.203-210
    • /
    • 2011
  • This study formulates the theoretical wheel-set model to evaluate wheel-climbing derailments of rolling stock due to collision, and verifies this theory with dynamic simulations. The impact forces occurring during collision are transmitted from a car body to axles through suspensions. As a result of combinations of horizontal and vertical forces applied to axles, rolling stock may lead to derailment. The derailment type will depend on the combinations of the horizontal and vertical forces, flange angle and friction coefficient. According to collision conditions, the wheel-lift, wheel-climbing or roll-over derailments can occur between wheel and rail. In this theoretical derailment model of wheelset, the wheel-climbing derailment types are classified into Climb-over, Climb/roll-over, and pure Roll-over according to derailment mechanism between wheel and rail, and we proposed the theoretical conditions to generate each derailment mechanism. The theoretical wheel-set model was verified by dynamic simulations.

A Basic Study on Wheel Flange Climbing using Model Wheelset

  • Nagumo, Yosuke;Tanifuji, Katsuya;Imai, Junichi
    • International Journal of Railway
    • /
    • v.3 no.2
    • /
    • pp.60-67
    • /
    • 2010
  • This paper deals with an experimental study on the wheel flange climbing of railway vehicles, which is a major factor leading to derailment. An experiment is carried out on a 1/5-scale model wheelset of a truck used on a standard-gauge track, which is placed on a roller rig. The lateral external force acting on the wheelset is ramped up until derailment occurs under the condition of a fixed attack angle and wheel-load unbalance ratio. Three parameters, the height of wheel lift, the lateral force, and the wheel load acting on the outer rail, are measured until derailment occurs. From these measurements, it is possible to observe the behavior of the wheelset and to elucidate how the attack angle, the wheel-load unbalance ratio and the lateral external force affect flange-climb derailment. Then, a numerical simulation is carried out using an analytical model based on a single wheelset. As a result, the flange-climb behavior observed in the experiment can be explained theoretically on the bases of the analytical results, although further improvement of the model is desired.

  • PDF

A Study on Prediction Method of Derailment Behaviors due to Cross-wind Considering Dynamic Effects of Wheel-rail Interaction (차륜-레일의 동적효과를 고려한 측풍 원인 탈선 예측방법 연구)

  • Kim, Myung Su;Koo, Jeong Seo
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.38 no.7
    • /
    • pp.699-709
    • /
    • 2014
  • This paper proposes a new method for predicting the derailment of a running train under cross-wind conditions, using the single wheelset derailment theory. The conventional theories used for predicting the derailment due to cross-winds were developed under the assumption that derailment will always be of the roll-over type, thus neglecting other possible types such as wheel-climbing, which may occur under special driving conditions. In addition, these theories do not consider running conditions such as dynamic wheel-rail interactions and friction effects. The new method considers the effects of dynamic wheel-rail interaction as well as those of lateral acceleration, rail cant, and cross-winds. The results of this method were compared and verified with those of the conventional methods and numerical simulations.

Utilization of wheel derailment test facilities (차륜탈선 시험설비의 활용방안)

  • Ham, Young-Sam;You, Won-Hee
    • Proceedings of the KSR Conference
    • /
    • 2011.05a
    • /
    • pp.1128-1133
    • /
    • 2011
  • This is a testing equipment system to analyze variation of creep force according to wheel-rail tread profile, running speed of vehicle, vertical and lateral force, wheel/rail contact point, attack angle and so on. The creep force affect vehicle derailment, especially climbing derailment. This system is composed of main frame, wheelset and rail disks driver, hydraulic actuator, controller, environmental chamber, safety system and so on.

  • PDF

Technologies for improving the running safety of a tram operating on the concrete embedded track (콘크리트 매립형 궤도를 운행하는 트램의 주행안전성 향상 기술)

  • Seo, Sung-il;Mun, Hyung-Suk;Kim, Sun-Chun
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.18 no.10
    • /
    • pp.717-724
    • /
    • 2017
  • To improve the running safety of a tram operating on a concrete embedded track, a bogie, the core system of the tram, was developed and fabricated. After it was integrated with the prototype car body, a short distance track with a sharp curve and steep gradient was constructed for the test operation. A formula to check the interference of the wheel flange with the track during running was proposed. Based on the results provided by the formula, the track was designed. Another simple formula was derived to estimate the derailment quotient and the wheel unloading ratio. During running on the track, the acceleration of the car body was measured and the interface status between the wheel and the track was monitored by a video system. According to the results calculated by these simple formulas, the derailment quotient and wheel unloading ratio were estimated to be within the safety criteria. In the actual test, no derailment occurred and the measured acceleration satisfied the criteria. Also, there was no interference between the wheel and track. The video monitoring results showed no signs of derailment, such as the climbing of the wheel. The pinion in the center showed good running safety, contacting smoothly with the rack. The measurements of environmental noise proved that the criteria were satisfied.

Validation of the vehicle dynamic model for the static vehicle testing (정차상태 시험 결과를 이용한 차량동특성 해석 모델의 검증)

  • Park, Kil-Bae;Seong, Jae-Ho
    • Proceedings of the KSR Conference
    • /
    • 2011.05a
    • /
    • pp.317-325
    • /
    • 2011
  • Vehicle model validation for the static vehicle testing has been done by comparison of the simulation results and test results and the parameters of the vehicle model to be used in the simulation have been adjusted to reflect the measured behaviour. The vehicle model fort the simulation should be validated by suitable tests and/or practical experience. The static vehicle test used to validate the vehicle model are the weight measurement, the wheel offloading test, the bogie rotational resistance test and the sway test. Finally, the computer simulation model has been validated and using the validated vehicle model the acceptance of the vehicle safety of the resistance to flange climbing derailment at low speed can be examined.

  • PDF