Influence of the railway vehicle properties in the running safety against crosswinds

2021 ◽  
Vol 217 ◽  
pp. 104732
Author(s):  
R. Heleno ◽  
P.A. Montenegro ◽  
H. Carvalho ◽  
D. Ribeiro ◽  
R. Calcada ◽  
...  
Keyword(s):  
Railway Vehicle ◽  
Running Safety

The effect of train composition on the running safety of low-flatcar wagons in braking and curving manoeuvres

2016 ◽  
Vol 231 (6) ◽  
pp. 666-677 ◽  
Author(s):  
Egidio Di Gialleonardo ◽  
Gabriele Cazzulani ◽  
Stefano Melzi ◽  
Francesco Braghin
Keyword(s):  
Numerical Simulations ◽  
Dynamic Behaviour ◽  
Good Alternative ◽  
Critical Conditions ◽  
Railway Vehicle ◽  
Freight Train ◽  
Running Safety ◽  
Experimental Campaign ◽  
Important Impact ◽  
Truck Transportation

Low-flatcar wagons represent a good alternative to freight truck transportation. In fact, the whole truck can be easily loaded on these wagons. However, due to the railway vehicle gauge, these vehicles present a particular design with an important impact on the dynamics of the trainset and on its derailment risk. The present work aims at analysing the dynamic behaviour of the trainset and the influence of the freight train composition on the derailment risk. Numerical simulations have been performed to identify the most critical conditions. Then, an experimental campaign has been carried out to evaluate the derailment risk associated to these conditions.

scholarly journals Influence of Suspension Parameters Changes of a Railway Vehicle on Output Quantities

2019 ◽  
Vol 10 (1) ◽  
pp. 20-29 ◽  
Author(s):  
Ján Dižo ◽  
Miroslav Blatnický ◽  
Stasys Steišūnas ◽  
Gediminas Vaičiūnas
Keyword(s):  
Dynamic Response ◽  
Ride Comfort ◽  
Suspension System ◽  
Railway Vehicle ◽  
Running Safety ◽  
Suspension Parameters ◽  
System A ◽  
Dynamic Analyses ◽  
Computer Analyses ◽  
Important Input

Abstract This article deals with computer analyses of output quantities of a railway vehicle depending on changing of parameters of suspension system. A passenger car was chosen for dynamic analyses. An analysed passenger railway vehicle uses two stage suspension system composed of coil springs and hydraulic dampers. Stiffness of coil springs of primary and secondary suspensions were defined for two states and its influence on output values in terms of quality and quantity was evaluated. As output variables, values of forces in a wheel/rail contact and accelerations in several locations on a wagon body floor were chosen. Values of forces in a wheel/rail contact indicate dynamic response of a railway vehicle running in terms of running safety and values of accelerations serve as important input for evaluation of passenger ride comfort.

scholarly journals Influence of stiffness characteristics of a railway track on output parameters in a multibody model

2020 ◽  
Vol 318 ◽  
pp. 01003
Author(s):  
Ján Dižo ◽  
Miroslav Blatnický
Keyword(s):  
Indirect Method ◽  
Ride Comfort ◽  
Direct Method ◽  
Point Of View ◽  
Railway Track ◽  
Railway Vehicle ◽  
Running Safety ◽  
Multibody Model ◽  
Stiffness Characteristics ◽  
Stiffness And Damping

The article is aimed at the research of the influence of stiffness characteristics included in a model of a railway track, which is the part of a multibody system. The other part of the multibody model is a railway vehicle. Authors are focused on the investigation of response of some selected output parameters under various values of input of stiffness and damping coefficients. The interaction of a railway vehicle and a railway track is studied. A passenger railway vehicle has been chosen for presented research. Outputs parameters are chosen in the passenger ride comfort point of view and the running safety point of view. The passenger ride comfort can be evaluated either by the direct method, when a real vehicle runs on a track and passengers evaluate a vehicle by means of their feelings during the ride or by means of the indirect method, when accelerometers are used for measuring accelerations in various positions of a tested wagon and subsequently values of accelerations are processed in required way. Then, the ride comfort is calculated and indexed by means of ride comfort indices. In the presented work, the indirect method has been used. In the computer multibody model of the wagon accelerations on a floor have been detected and the mean ride comfort for a person is assessed. The ride safety is most often determined by waveforms of vertical wheel forces, lateral wheel forces and the derailment quotient.

Running Safety Estimation of Korean Style High Speed Railway Vehicle

2004 ◽  
Vol 270-273 ◽  
pp. 1989-1994 ◽  
Author(s):  
Young Sam Ham ◽  
Jai Sung Hong ◽  
Taek Yul Oh
Keyword(s):  
High Speed ◽  
Railway Vehicle ◽  
High Speed Railway ◽  
Running Safety ◽  
Safety Estimation

scholarly journals Prediction of Theoretical Derailments Caused by Cross-Winds with Frequency

2021 ◽  
Vol 11 (7) ◽  
pp. 2947
Author(s):  
JunWoo Kim ◽  
InHo Song ◽  
JeongSeo Koo
Keyword(s):  
High Speed ◽  
Technical Specification ◽  
Design Stage ◽  
Railway Vehicle ◽  
International Union ◽  
Running Safety ◽  
Wind Speeds ◽  
Rail Irregularities ◽  
Wind Frequency ◽  
Theoretical Results

In this paper, theoretical derailment equations for cross-wind with frequency were derived to assess running safety. For a KTX (Korean high-speed train) unit, the wheel unloading ratios, which are the criteria for evaluating derailments in UIC (International union of railways) and TSI (Technical Specification for Interoperability) regulations, were calculated through the formula under the driving regulations according to cross-wind speeds, and the theoretical results were compared and evaluated through a multibody dynamics (MBD) simulation. In addition, the wheel unloading ratios were calculated for various frequencies of cross-winds. As a result of the formula and MBD, the wheel unloading ratios were shown to increase rapidly regardless of the dampers in suspension when the cross-wind frequency and the natural frequency of a vehicle were in agreement. Finally, we calculated the changes of wheel unloading ratio for different track gauges and found that these theoretical equations could calculate more accurate results than the existing Kunieda’s formula. The formula derived in this study has the advantage of considering various variables, such as fluctuant cross-winds, rail irregularities, and derailment behaviors, which were not considered in previous studies or Kunieda’s formula. It could be used for setting suspensions or railway vehicle specifications in the initial design stage.

Running Safety and Comfort Analysis of Railway Vehicles Moving on Curved Tracks

2014 ◽  
Vol 14 (04) ◽  
pp. 1450004 ◽  
Author(s):  
Yung-Chang Cheng ◽  
Chin-Te Hsu
Keyword(s):  
Degrees Of Freedom ◽  
Lateral Displacement ◽  
Equations Of Motion ◽  
Creep Model ◽  
Railway Vehicle ◽  
Nonlinear Creep ◽  
Running Safety ◽  
Comfort Index ◽  
Vertical Displacements ◽  
Index Formulas

Using a heuristic linear creep model, this study derives the governing differential equations of motion for the railway vehicle traveling on curved tracks. The railway vehicle is modeled as a car system with 27 degrees-of-freedom (DOFs), taking into account the lateral and vertical displacements, roll and yaw angles of the wheelsets and truck frames, as well as the lateral displacement, roll and yaw angles of the car body. The effects of railway vehicle speeds on the derailment quotients and offload factors related to running safety are evaluated by both the linear and nonlinear creep models for various radii of curved tracks. Using the Sperling and modified Sperling index formulas, the effects of railway vehicle speeds on lateral riding quality and comfort are illustrated for the two models with various radii of curved tracks. Furthermore, the effects of railway vehicle speeds on the lateral Sperling comfort index of the 27-DOF car model are presented and compared for various suspension parameters. Finally, the acceptable region for riding quality and comfort are drawn.

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