Longitudinal Train Dynamics

2014 ◽  
pp. 144-213
Keyword(s):  
Train Dynamics

Investigation of Train Dynamics in Passing Through Curves Using a Full Model

Joint Rail ◽  
2004 ◽  
Author(s):  
Mohammad Durali ◽  
Mohammad Mehdi Jalili Bahabadi
Keyword(s):  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Three Dimensional ◽  
Full Model ◽  
Bogie Frame ◽  
Nonlinear Characteristics ◽  
Train Derailment ◽  
Train Dynamics

In this article a train model is developed for studying train derailment in passing through bends. The model is three dimensional, nonlinear, and considers 43 degrees of freedom for each wagon. All nonlinear characteristics of suspension elements as well as flexibilities of wagon body and bogie frame, and the effect of coupler forces are included in the model. The equations of motion for the train are solved numerically for different train conditions. A neural network was constructed as an element in solution loop for determination of wheel-rail contact geometry. Derailment factor was calculated for each case. The results are presented and show the major role of coupler forces on possible train derailment.

Recent Advances in Control-Oriented Modeling of Automotive Power Train Dynamics

2006 ◽  
Vol 11 (5) ◽  
pp. 513-523 ◽  
Author(s):  
J. Deur ◽  
J. Petric ◽  
Asgari ◽  
D. Hrovat
Keyword(s):  
Power Train ◽  
Recent Advances ◽  
Train Dynamics

Comparison of Energy-Saving Driving Style Strategies

2016 ◽  
Author(s):  
Yigit Fidansoy ◽  
Sohejl Wanjani ◽  
Sebastian Schmidt
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Fossil Fuels ◽  
Design Thinking ◽  
Energy Savings ◽  
Driving Style ◽  
Advisory Systems ◽  
Train Dynamics ◽  
Input Variables ◽  
And Training

Due to the increasing scarcity of fossil fuels and the climate change, the importance of energy efficiency is increasing. This importance is major especially in areas where the energy consumption is high. Rail transport depicts such an area. The highest proportion of energy consumed in the railway is the so called traction energy. This energy is required for the train run. In the timetable, allowances leave a margin for the driving style of train run. By the selective use of strategies that change the driving style, it is possible to exploit these allowances and reduce the traction energy consumption. The first objective of this study deals with the development of algorithms for energy-saving driving style. First, the necessary input variables of the algorithms based on the literature research and the formulas of train dynamics were determined. Then the algorithms were developed to create different energy-saving driving styles, resulting choose the best result which should be shown as a driving recommendation. The developed algorithms were used in an application example in order to calculate the potential of energy-savings. The example should represent the influence of the input variables for a comparison of different situations. At last the acceptance of the determined driving strategies in practice was investigated. By implementing the design thinking method it was identified that driver advisory systems and training programs are necessary to facilitate energy-saving driving in practice.

Analysis of Brake Failure and Runaway Accidents in Mountain Terrain in Canada

2013 ◽  
Author(s):  
Daoxing Chen
Keyword(s):  
Dynamics Simulation ◽  
Contributing Factors ◽  
Friction Heat ◽  
Mountain Terrain ◽  
Maintenance Practice ◽  
Train Operation ◽  
Brake Application ◽  
Property Loss ◽  
Train Dynamics ◽  
Mountain Terrains

A number of serious rail runaway accidents have occurred in recent years on long and high grade downhill tracks in mountain terrains in Canada, causing fatal injuries and huge property loss. They were caused by brake failure, misunderstanding of brake features, maintenance deficiency and/or improper brake application on the trains. Train dynamics simulation, brake ratio testing, and dynamometer testing on friction heat fade helped disclose the causes and contributing factors in the cases presented in this paper. Guidelines were revised for safer train operation, equipment requirements and maintenance practice in the mountain terrain conditions.

scholarly journals Comparisons Between Braking Experiments and Longitudinal Train Dynamics Using Friction Coefficient and Braking Pressure Modeling in a Freight Train

2020 ◽  
Vol 14 (1) ◽  
pp. 154-163
Author(s):  
Don Bum Choi ◽  
Rag-Gyo Jeong ◽  
Yongkook Kim ◽  
Jangbom Chai
Keyword(s):  
Friction Coefficient ◽  
Time Integration ◽  
Expansion Method ◽  
Dynamics Simulation ◽  
Dynamic Simulations ◽  
Freight Train ◽  
Emergency Braking ◽  
Braking Distance ◽  
Train Dynamics ◽  
Simulation Results

Background: This paper describes the predictions and validation of the pneumatic emergency braking performance of a freight train consisting of a locomotive and 20 wagons, generally operated in Korea. It suggests the possibility of replacing the expensive and time-consuming train running tests with longitudinal train dynamic simulations. Methods: The simulation of longitudinal train dynamics of a freight train uses the time integration method of EN 14531. For reasonable simulation results, the characteristics of the train and brake equipment must be considered. For the train characteristics, specifications provided by the vehicle manufacturer are used. The braking characteristics are analyzed by friction coefficient tests and a braking pressure model. The friction coefficients of a locomotive and wagons are tested with a dynamo test bench and statistically expanded to account for variability. Freight trains should take into account the braking delay time. To reflect this in the simulation, the brake cylinder pressure pattern model uses pressures and exponential empirical equations measured at selective positions in a train of 50 vehicles. The simulation results are validated in comparison with those of the braking tests of a freight train consisting of 1 locomotive and 20 wagons. Results: The results of the longitudinal dynamics simulation show very similar results to the running test results based on the speed profile and braking distance. Conclusion: In particular, the statistical expansion method of the friction coefficient enables robust prediction of the distribution of the braking distance. The simulation can reduce or make up for costly and time-consuming repeated braking tests and reduce the risks that may arise during testing.

scholarly journals An integrated numerical framework to investigate the running safety of overlong freight trains

2020 ◽  
Vol 235 (1) ◽  
pp. 47-60
Author(s):  
Visakh V Krishna ◽  
Daniel Jobstfinke ◽  
Stefano Melzi ◽  
Mats Berg
Keyword(s):  
Compressive Force ◽  
Radio Communication ◽  
Freight Train ◽  
Running Safety ◽  
Loading Patterns ◽  
Train Operation ◽  
Train Dynamics ◽  
Fail Safe ◽  
P Type ◽  
Brake Block

Long freight trains up to 1500 m in length are currently not in regular operation in Europe. One of the important reasons for the same is high inter-wagon forces generated during the operation, especially when pneumatic (P-type) brake systems are used. For long trains with multiple locomotives at different positions along the train, radio communication with necessary fail-safe mechanisms can be used to apply the brakes. Long freight train operation on a given line is subjected to various attributes such as braking/traction scenarios, loading patterns, wagon geometries, brake-block materials, buffer types, track design geometries, etc., which are referred to as heterogeneities. The complex longitudinal train dynamics arising in the train due to various heterogeneities play a major role in determining its running safety. In this context, the maximum in-train force refers to the maximum force developed between any two wagons along the train during operation. The tolerable longitudinal compressive force is the maximum compressive force that can be exerted on a wagon without resulting in its derailment. Here, the authors adopt a bottom-up approach to model pneumatic braking systems and inter-wagon interactions in multibody simulation environments to study the complex longitudinal train dynamics behavior and estimate maximum in-train forces and tolerable longitudinal compressive forces, subjected to various heterogeneities. These two force quantities intend to facilitate a given freight train operation by providing guidelines regarding the critical heterogeneities, that currently limit its safe operation. In doing so, the authors propose the notion to have an operation-based approval for long freight trains using the simulations-based tool.

Dynamic Simulation and Test for the Valve Train Dynamics

2011 ◽  
Vol 117-119 ◽  
pp. 15-19 ◽  
Author(s):  
Cai Yun Guan ◽  
You Ming Chen ◽  
Wen Jie Qin
Keyword(s):  
Dynamic Model ◽  
Contact Stiffness ◽  
Quantitative Agreement ◽  
Measured Data ◽  
Valve Train ◽  
Parameter Determination ◽  
Cam Follower ◽  
Train Dynamics ◽  
Simulation Results

This paper presents the development of a dynamic model of the valve train of one engine. During the parameter determination of the model, finite element method is used to calculate the contact stiffness of the cam-follower . The simulation results of the model are compared with measured data of the valve train at same speed. Excellent quantitative agreement is found between the numerical and experimental results and the validity of the dynamic model can be verified.

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