scholarly journals Determining Effects of Wagon Mass and Vehicle Velocity on Vertical Vibrations of a Rail Vehicle Moving with a Constant Acceleration on a Bridge Using Experimental and Numerical Methods

2015 ◽  
Vol 2015 ◽  
pp. 1-15 ◽  
Author(s):  
C. Mızrak ◽  
İ. Esen
Keyword(s):  
Moving Loads ◽  
Anova Analysis ◽  
Constant Acceleration ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Taguchi Experiment Design ◽  
Vehicle Velocity ◽  
Roller Rig ◽  
Vertical Vibrations ◽  
Derailment Safety

Vibrations are vital for derailment safety and passenger comfort which may occur on rail vehicles due to the truck and nearby conditions. In particular, while traversing a bridge, dynamic interaction forces due to moving loads increase the vibrations even further. In this study, the vertical vibrations of a rail vehicle at the midpoint of a bridge, where the amount of deflection is expected to be maximum, were determined by means of a 1 : 5 scaled roller rig and Newmark-βnumerical method. Simulations for different wagon masses and vehicle velocities were performed using both techniques. The results obtained from the numerical and experimental methods were compared and it was demonstrated that the former was accurate with an 8.9% error margin. Numerical simulations were performed by identifying different test combinations with Taguchi experiment design. After evaluating the obtained results by means of an ANOVA analysis, it was determined that the wagon mass had a decreasing effect on the vertical vibrations of the rail vehicle by 2.087%, while rail vehicle velocity had an increasing effect on the vibrations by 96.384%.

scholarly journals Effect of Rail Vehicle–Track Coupled Dynamics on Fatigue Failure of Coil Spring in a Suspension System

2021 ◽  
Vol 11 (6) ◽  
pp. 2650
Author(s):  
Sunil Kumar Sharma ◽  
Rakesh Chandmal Sharma ◽  
Jaesun Lee
Keyword(s):  
Mathematical Model ◽  
Fatigue Fracture ◽  
Suspension System ◽  
Railway Vehicle ◽  
Coil Spring ◽  
Internal Resonances ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Stress Result ◽  
Wheel Track

In a rail vehicle, fatigue fracture causes a significant number of failures in the coil spring of the suspension system. In this work, the origin of these failures is examined by studying the rail wheel–track interaction, the modal analysis of the coil springs and the stresses induced during operation. The spring is tested experimentally, and a mathematical model is developed to show its force vs. displacement characteristics. A vertical 10-degree-of-freedom (DOF) mathematical model of a full-scale railway vehicle is developed, showing the motions of the car body, bogies and wheelsets, which are then combined with a track. The springs show internal resonances at nearly 50–60 Hz, where significant stresses are induced in them. From the stress result, the weakest position in the innerspring is identified and a few guidelines are proposed for the reduction of vibration and stress in rail vehicles.

scholarly journals Assessment of a rail vehicle running with the damaged wheel on a ride comfort for passengers

2018 ◽  
Vol 157 ◽  
pp. 03004 ◽  
Author(s):  
Ján Dižo ◽  
Miroslav Blatnický ◽  
Stasys Steišūnas ◽  
Blanka Skočilasová
Keyword(s):  
Ride Comfort ◽  
Railway Wheel ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Dynamic Analyses ◽  
Wheel Flat

In certain conditions rail vehicles wheels can be during operation damaged. Then, the profile of wheels is no longer circular, but it is changed depending on the type and severity of defects. When such rail vehicle with the damaged wheel operates, the quality of a ride comfort for passenger is degraded. This article is focused on the assessment of ride comfort for passenger based on results obtained from dynamic analyses. Simulations and calculations were carried out in commercial multibody software. In our research we considered one type of the railway wheel untrueness – wheel-flat. This type of wheel damaging is relatively common and has such influence on the ride comfort for passenger worsening, which needs to be detected and investigated.

Selected issues of automation of rail vehicles operation

2019 ◽  
Vol 126 ◽  
pp. 75-85
Author(s):  
Emilia Koper ◽  
Andrzej Kochan ◽  
Przemysław Ilczuk
Keyword(s):  
Traffic Safety ◽  
Probability Estimation ◽  
Functional Classification ◽  
Legal Analysis ◽  
Vehicle Traffic ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Scientific Technical

This article presents a synthesis of the assessment opportunities for the implementation of automation of rail vehicles in Poland. The evaluation was to identify the threats to the implementation of automation of the above mentioned vehicles and then to assign to them the effects and probabilities of occurrence. For the purpose of probability estimation, a review of selected scientific, technical, formal and legal sources was carried out. Definitions of grades of automation (GoA) were given, assigning technical and safety functionalities to them. Functional classification has been made with regard to traffic safety. The problem of passengers' and drivers' social feelings towards the introduction of automatic vehicles has been pointed out. A formal and legal analysis of the possibility of implementing automatic rail vehicle traffic in Poland was also carried out.

Selected issues of automation of rail vehicles operation

2019 ◽  
Vol 127 ◽  
pp. 37-47
Author(s):  
Emilia Koper ◽  
Andrzej Kochan ◽  
Przemysław Ilczuk
Keyword(s):  
Traffic Safety ◽  
Probability Estimation ◽  
Functional Classification ◽  
Legal Analysis ◽  
Vehicle Traffic ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Scientific Technical

This article presents a synthesis of the assessment opportunities for implementing the automation of rail vehicles in Poland. The evaluation was to identify the threats to the automation of the above-mentioned vehicles and then assign to them the effects and probabilities of occurrence. A review of selected scientific, technical, formal, and legal sources was carried out for probability estimation. Definitions of Grades of Automation (GoA) were given, assigning technical and safety functionalities to them. The functional classification has been made concerning traffic safety. The problem of passengers' and drivers' social feelings towards introducing automatic vehicles has been pointed out. A formal and legal analysis of the possibility of implementing automatic rail vehicle traffic in Poland was also carried out.

Dynamics Analysis and Power Allocation Strategy Research for a New Hybrid Electric Urban Rail Vehicle

2013 ◽  
Vol 300-301 ◽  
pp. 93-98 ◽  
Author(s):  
Yan Qiu Chen ◽  
Ji Ye Zhang ◽  
Xiao Xi Chen ◽  
Ming Li
Keyword(s):  
Power Allocation ◽  
General Structure ◽  
Point Of View ◽  
Allocation Strategy ◽  
Electric Locomotive ◽  
Strategy Research ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Urban Rail ◽  
Hybrid Electric

In order to improve the efficiency and environment-friendliness of urban rail vehicles, a new hybrid electric locomotive is proposed. The general structure of the proposed hybrid electric locomotive is given and analyzed from a dynamics point of view. The calculation method of power output and its allocation strategy is discussed. A simulation is conducted in HELSP(Hybrid Electric Locomotive Simulation Platform) to verify the performance of the power allocation strategy. The result indicates that the function of allocating power can be properly realized, and the regeneration energy from frequent braking can be absorbed by the power storage of the vehicle.

scholarly journals Rail Vehicle Localization Exploiting Rail Track Georeferenced Coordinates

2015 ◽  
Vol 1 (2) ◽  
pp. 1-12
Author(s):  
António João Ferreira ◽  
José Miguel Almeida ◽  
Eduardo Silva
Keyword(s):  
Dead Reckoning ◽  
Satellite System ◽  
Vehicle Localization ◽  
Rail Vehicle ◽  
Position Errors ◽  
Railroad Tracks ◽  
Rail Vehicles ◽  
Global Navigation Satellite ◽  
Global Uncertainty

A novel dead reckoning algorithm conceived for localization of small inspection rail vehicles in Global Navigation Satellite System (GNSS) denied environments is presented. This work focus on simplifying the rail vehicle localization task, taking into account restrictions on movement imposed by the railroad tracks. Considering that dead reckoning techniques accumulate errors over time, leading to increasing global uncertainty, a method was designed to correct the estimates and also smooth trajectory errors backwards in time, through visualization of global landmarks. Results show the effectiveness of this approach in reducing long-term position errors. The current document reports real railroad experiments, featuring a specially designed non-motorized mobile modeling vehicle.

scholarly journals Study of rail vehicles movement characteristics improvement in curves using fuzzy logic mechatronic systems

2019 ◽  
Vol 294 ◽  
pp. 03019 ◽  
Author(s):  
Mikhail Kapitsa ◽  
Evgen Mikhailov ◽  
Sergii Kliuiev ◽  
Stanislav Semenov ◽  
Maksim Kovtanets
Keyword(s):  
Fuzzy Logic ◽  
Horizontal Plane ◽  
Position Control ◽  
Navigation Systems ◽  
Mechatronic Systems ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Movement Characteristics ◽  
Curved Section ◽  
System Operating

The article deals with the effectiveness of reducing the level of force interaction of the rail vehicle wheels with rails in curved sections of the track through the use of mechatronic position control systems for wheel pairs in the rail gauge in the horizontal plane. The approaches to the creation of such a mechatronic system operating on the principles of fuzzy logic are described. To determine the angles of attack of wheels on the rails, it was proposed to use the acoustic emission indicators of the contact of the wheel with the rail. To determine the direction of curvature of the rail track, it is advisable to use data from navigation systems. The study of the dynamics of the rail vehicle during the passage of a curved section of the track in real time was carried out using the Matlab/Simulink software package. The proposed mechatronic control system for the position of the wheel sets in the horizontal plane allows to ensure their optimal installation under various driving conditions in the rail gauge. This makes it possible to minimize the angles of attack of the wheels and reduce the forces of the horizontal interaction of the wheels with the rails.

scholarly journals Benefits of mechatronically guided vehicles on railway track switches

2018 ◽  
Vol 234 (3) ◽  
pp. 276-288 ◽  
Author(s):  
Nabilah Farhat ◽  
Christopher P Ward ◽  
Roger Dixon ◽  
Roger M Goodall
Keyword(s):  
High Speed ◽  
Simulation Software ◽  
Railway Track ◽  
Ride Quality ◽  
Switching Function ◽  
Vehicle Model ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Conventional Rail ◽  
Multi Body

Conventional rail vehicles struggle to optimally satisfy the different suspension requirements for various track profiles, such as on a straight track with stochastic irregularities, curved track or switches and crossings, whereas mechatronically guided railway vehicles promise a large advantage over conventional vehicles in terms of reduced wheel–rail wear, improved guidance and opening new possibilities in vehicle architecture. Previous research in this area has looked into guidance and steering using multi-body simulation models of mechatronic rail vehicles of three different mechanical configurations – secondary yaw control, actuated solid-axle wheelset and driven independently rotating wheelsets (DIRW). The DIRW vehicle showed the best performance in terms of reduced wear and minimal flange contact and is therefore chosen in this paper for studying the behaviour of mechatronically guided rail vehicles on conventional switches and crossings. In the work presented here, a mechatronic vehicle with the DIRW configuration is run on moderate and high-speed track switches. The longer term motivation is to perform the switching function from on-board the vehicle as opposed to from the track as is done conventionally. As a first step towards this, the mechatronic vehicle model is compared against a conventional rail vehicle model on two track scenarios – a moderate speed C type switch and a high-speed H switch. A multi-body simulation software is used to produce a high fidelity model of an active rail vehicle with independently rotating wheelsets where each wheel has an integrated ‘wheelmotor’. This work demonstrates the theory that mechatronic rail vehicles could be used on conventional switches and crossings. The results show that the mechatronic vehicle gives a significant reduction in wear, reduced flange contact and improved ride quality on the through routes of both moderate and high-speed switches. On the diverging routes, the controller can be tuned to achieve minimal flange contact and improved ride quality at the expense of higher creep forces and wear.

scholarly journals An investigation into intermittent electrification strategies and an analysis of resulting CO2 emissions using a high-fidelity train model

2021 ◽  
Author(s):  
Bilal M. Abdurahman ◽  
Tim Harrison ◽  
Christopher P. Ward ◽  
William J. B. Midgley
Keyword(s):  
Diesel Engine ◽  
High Fidelity ◽  
Vehicle Model ◽  
Rail Vehicle ◽  
Fast Estimation ◽  
Rail Vehicles ◽  
Self Powered ◽  
Near Term ◽  
Reduce Emissions ◽  
Fidelity Model

AbstractA near-term strategy to reduce emissions from rail vehicles, as a path to full electrification for maximal decarbonisation, is to partially electrify a route, with the remainder of the route requiring an additional self-powered traction option. These rail vehicles are usually powered by a diesel engine when not operating on electrified track and are referred to as bi-mode vehicles. This paper analyses the benefits of discontinuous electrification compared to continuous electrification using the CO2 estimates from a validated high-fidelity bi-mode (diesel-electric) rail vehicle model. This analysis shows that 50% discontinuous electrification provides a maximum of 54% reduction in operational CO2 emissions when compared to the same length of continuously electrified track. The highest emissions savings occurred when leaving train stations where vehicles must accelerate quickly to line speed. These results were used to develop a linear regression model for fast estimation of CO2 emissions from diesel running and electrification benefits. This model was able to estimate the CO2 emissions from a route to within 10% of that given by the high-fidelity model. Finally, additional considerations such as cost and the embodied CO2 in electrification infrastructure were analysed to provide a comparison between continuous and discontinuous electrification. Discontinuous electrification can cost up to 56% less per reduction in lifetime emissions than continuous electrification and can save up to 2.3 times more lifetime CO2 per distance electrified.

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