scholarly journals Modeling the longitudinal dynamics of electric multiple units with Xcos/Scilab software

2021 ◽  
Vol 1199 (1) ◽  
pp. 012066
Author(s):  
J Jackiewicz
Keyword(s):  
Dynamic Modeling ◽  
Computer Simulations ◽  
Longitudinal Dynamics ◽  
Longitudinal Dynamic ◽  
Vibration Protection ◽  
Dynamic Forces ◽  
Multiple Units

Abstract During the traction and braking of trains, substantial longitudinal dynamic forces might occur in couplers. The method of modeling these forces for two different electric multiple units (EMUs) is presented in this study. For the EMUs consisted of independent vehicles, each of which rests on two bogies, computer simulations were carried out. Simulations were also executed for EMUs with Jacobs bogies, which support bodies of two adjacent carriages. The dynamic modeling of vibration protection train systems includes nonlinearities.

scholarly journals Influence of resistance to motion of railway vehicles on the longitudinal trains dynamics

2018 ◽  
Vol 178 ◽  
pp. 06003
Author(s):  
Camil Crăciun ◽  
Cătălin Cruceanu
Keyword(s):  
The Body ◽  
Simulation Program ◽  
Longitudinal Dynamics ◽  
Railway Vehicles ◽  
Longitudinal Dynamic ◽  
Dynamic Forces ◽  
Braking Process

Longitudinal dynamics of trains is a subject that generates discussions and views on the parameters that interfere and influence both the size of the forces and their distribution in the train body. The paper is a study to determine the influence of resistances to motion on the longitudinal dynamic forces that develop in the body of the train in the braking process. For this, a train study model of ten identical vehicles, to which the locomotive may or may not be attached, is adopted. Initially, the simulation program for the non-locomotive model is run in two variants: with and without introducing additional resistances to motion, followed by the same simulations but with the locomotive introduced and a wagon removed, thus the number of vehicles remains the same for all the cases presented.

scholarly journals The effects of filling characteristics on the longitudinal forces developed in the braking train

2019 ◽  
Vol 290 ◽  
pp. 08005
Author(s):  
Camil Ion Crăciun ◽  
Cătălin Cruceanu
Keyword(s):  
Compressed Air ◽  
Railway Vehicle ◽  
Inertial Forces ◽  
Longitudinal Dynamic ◽  
Dynamic Forces ◽  
Filling Characteristics ◽  
Brake Cylinder ◽  
Global Research

Determination of longitudinal dynamic forces, size assessment as well as their distribution in the train body is, and will be a subject of global research. As observed from the beginning of the evolution of the railway vehicle and the train itself, the main reason for the occurrence of longitudinal dynamic forces is represented by the differences in inertial forces between the consecutive train vehicles. These inertial forces are influenced by the braking forces developed on each vehicle. The brake with which a railway vehicle is equipped is the pneumatic brake with compressed air. It evacuates the air from the train’s general pipeline, increasing the pressure in the brake cylinders of each vehicle. The brake command and cylinder filling is more delayed on long trains compared to short ones. Thus, the brake can operate in two ways, the fast-action brake and the slow-action brake. In this paper, we aim to highlight the influence of the brake type by the brake cylinder filling characteristic of the dynamic longitudinal reactions. It will be analysed on a simplified train model the magnitude and distribution of longitudinal dynamic forces obtained using both braking systems.

About Longitudinal Dynamics of Classical Passenger Trains during Braking Actions

2013 ◽  
Vol 378 ◽  
pp. 74-81 ◽  
Author(s):  
Cătălin Cruceanu ◽  
Camil Ion Crăciun
Keyword(s):  
Traffic Safety ◽  
Numerical Examples ◽  
Longitudinal Dynamics ◽  
Braking System ◽  
Dynamic Forces ◽  
Passenger Trains

There are presented and analyzed specific aspects regarding the main mechanic and pneumatic issues determining the in-train dynamic forces developed during braking actions. Particularities in case of passenger trains are highlighted, with the aim of proving that even in the case of short trains, fitted with UIC type P braking system, longitudinal dynamics can cause significant reactions whose effect cannot be neglected, both in terms of traffic safety and comfort. Numerical examples presented stand for this.

Researches on the Behavior of the Supporting Structure of Railway Traction Vehicles under the Effect of Shock Dynamic Forces

2014 ◽  
Vol 659 ◽  
pp. 237-242
Author(s):  
Ioan Sebesan ◽  
Gabriel Popa ◽  
Marius Adrian Spiroiu
Keyword(s):  
Traffic Safety ◽  
Rolling Process ◽  
Railway Vehicle ◽  
Frontal Impact ◽  
Stick Slip ◽  
Driving System ◽  
Supporting Structure ◽  
Longitudinal Dynamic ◽  
Dynamic Forces ◽  
Railway Traction

During circulation the railway vehicle is subjected to the action of dynamic forces under the effect of shocks that appear in the driving system caused by stick slip phenomenon, dynamic forces arising from the rolling process when the wheelset is passing over accidental vertical unevenness of the track and also longitudinal dynamic forces occurring in the case of buffering, respectively those caused by frontal impact (the crash forces). The present paper presents the mechanical and mathematical models which are underlying the evaluation of the magnitude of these forces as well as their effects on the resistance of supporting structure of the vehicle and on traffic safety.

Distribution of Longitudinal Forces in the Body of Passenger Trains

2015 ◽  
Vol 809-810 ◽  
pp. 1175-1180 ◽  
Author(s):  
Camil Ion Crăciun ◽  
Mădălina Dumitriu
Keyword(s):  
Numerical Simulations ◽  
Mechanical Model ◽  
Rigid Bodies ◽  
The Body ◽  
Nonlinear Characteristic ◽  
Braking System ◽  
Longitudinal Dynamic ◽  
Dynamic Forces ◽  
Passenger Trains ◽  
Over Time

The distribution and the size of longitudinal dynamic forces that develop in the train body found in braking system are influenced by the length of the train. To determine these forces, it is used a mechanical model consisting of rigid bodies, representing the train vehicles, connected by elastic and damping elements with the nonlinear characteristic that shapes the buffer and draw-gear. The results based on numerical simulations highlight the emergence of dynamic longitudinal forces during braking, their evolution over time and the distribution of maximum compression and stretching forces that develop in buffer and draw-gear devices, for different lengths of the passenger train.

scholarly journals Coupler force reduction method for multiple-unit trains using a new hierarchical control system

2021 ◽  
Author(s):  
Jacek Jackiewicz
Keyword(s):  
Control System ◽  
Hierarchical Control ◽  
Cruise Control ◽  
Longitudinal Dynamic ◽  
Dynamic Forces ◽  
The Hierarchical Structure ◽  
Master Level ◽  
Multiple Unit ◽  
Control Configuration ◽  
Force Reduction

AbstractDuring traction and braking of multiple-unit trains, substantial longitudinal dynamic forces might occur in couplers due to the non-optimal distribution of traction and braking forces generated by self-propelled carriages. These dynamic forces might create shocks affecting the reduction of endurance of the weakest train structural components primarily. Thus, the overall operational safety of the train is also lowered. The purpose of the paper is to develop a new control system to supervise the activities related to the longitudinal dynamics of each train carriage in a multiple-unit train to reduce the longitudinal coupler forces acting during train traction and braking. The hierarchical structure of the control system consists of two levels. The first master level of control works like standard cruise control. However, the reduction of longitudinal coupler forces is achieved by applying a second level of slave control systems with a control configuration of feedback compensation.

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