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 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.

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.

Effects of Mechanical Wheel Slide Protection Devices Action on Railway Vehicles Braking Process

2015 ◽  
Vol 809-810 ◽  
pp. 1085-1090 ◽  
Author(s):  
Cătălin Cruceanu ◽  
Camil Ion Crăciun ◽  
Ioan Cristian Cruceanu
Keyword(s):  
Cast Iron ◽  
Numerical Simulations ◽  
High Power ◽  
Air Pressure ◽  
Simulation Program ◽  
Disc Brake ◽  
Railway Vehicles ◽  
Protection Devices ◽  
Braking Process ◽  
Brake Cylinder

The paper investigates the effects of mechanical wheel slide protection devices (WSPD) on the braking capacity for coaches equipped with disc or cast iron block brakes. Decelerations and jerks, that affect the passengers comfort, are also analyzed. An original simulation program, based on experimentally determined air pressure evolutions in brake cylinder is used for this purpose. Results of numerical simulations show that in the case of repeated actuations of mechanical WSPDs, disc brake vehicles are more affected in terms of braking capacity. Regarding jerks during braking actions, in both normal and low adhesion conditions, vehicles equipped with high power cast iron block brake with two pressure levels prove to be more affected.

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.

Model Predictive Control Application to Flexible-Bodied Railway Vehicles for Vibration Suppression

2013 ◽  
Vol 10 ◽  
pp. 25-35
Author(s):  
P.E. Orukpe
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
High Speed ◽  
Ride Comfort ◽  
The Body ◽  
Ride Quality ◽  
Linear Matrix ◽  
Railway Vehicle ◽  
Railway Vehicles ◽  
Effective Manner

In this paper, we apply model predictive control (MPC) based on mixed H2/H to active vibration control of the flexibility of railway vehicle to improve ride quality. However, the flexibility in the body of high-speed railway vehicles creates difficulties which in practice may result in the body structure being heavier than what it is supposed to be. The use of active suspension helps to model the vehicle and its flexibility in an effective manner. Conventional control approaches are compared with linear matrix inequality MPC technique using flexible-bodied railway vehicle as an example. The result indicates that the MPC technique performs better in improving ride comfort compared to the passive and classical techniques when flexible modes are present.

Posthumanism

2018 ◽  
Author(s):  
Diane Marie Keeling ◽  
Marguerite Nguyen Lehman
Keyword(s):  
Human Subject ◽  
Quantum Physics ◽  
The Body ◽  
Western Philosophy ◽  
Philosophical Perspective ◽  
Renaissance Humanism ◽  
Dynamic Forces ◽  
The World ◽  
The Mind ◽  
Scholarly Attention

Posthumanism is a philosophical perspective of how change is enacted in the world. As a conceptualization and historicization of both agency and the “human,” it is different from those conceived through humanism. Whereas a humanist perspective frequently assumes the human is autonomous, conscious, intentional, and exceptional in acts of change, a posthumanist perspective assumes agency is distributed through dynamic forces of which the human participates but does not completely intend or control. Posthumanist philosophy constitutes the human as: (a) physically, chemically, and biologically enmeshed and dependent on the environment; (b) moved to action through interactions that generate affects, habits, and reason; and (c) possessing no attribute that is uniquely human but is instead made up of a larger evolving ecosystem. There is little consensus in posthumanist scholarship about the degree to which a conscious human subject can actively create change, but the human does participate in change. As distinguished from posthumanism, humanism is credited with attributing the conscious and intentional human subject as the dominant source of agency most worthy of scholarly attention. Since its inception during the Renaissance, humanism has been constituted in various ways throughout history, but as a collective body of literature, the human is typically constituted through humanism as: (a) autonomous from nature given the intellectual faculties of the mind that controls the body, (b) uniquely capable of and motivated by speech and reason, and (c) an exceptional animal that is superior to other creatures. Humanist assumptions concerning the human are infused throughout Western philosophy and reinforce a nature/culture dualism where human culture is distinct from nature. In contrast, a posthumanist scholar rejects this dichotomy through understanding the human as entangled with its environment. A posthumanist scholar of communication typically integrates scholarship from a variety of other disciplines including, but not limited to: art, architecture, cybernetics, ecology, ethology, geology, music, psychoanalysis, and quantum physics.

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.

The Vertical Forces Introduced by Wind on the Active Pantograph from Bodywork of Locomotive LE 060 EA of 5100 kW

2015 ◽  
Vol 809-810 ◽  
pp. 1115-1120 ◽  
Author(s):  
Sorin Arsene
Keyword(s):  
Comparative Analysis ◽  
Power Supply ◽  
High Speed ◽  
High Performance ◽  
The Body ◽  
Vehicle Body ◽  
Aerodynamic Forces ◽  
Railway Vehicles ◽  
Railway Traction ◽  
Electric Railway

Gusts of wind with high speed can adversely affect the operation of the electric railway vehicles. These vehicles are able to move and to obtain a high performance, as long as the power supply is ensured. The variation of the vertical forces for maintaining contact between pantograph and catenary may cause interruption of the power supply of the electric railway traction vehicles. The placement of the capture equipment on the vehicle body determines appearance of aerodynamic forces acting on it. To see which are the vertical forces introduced by wind on active capture equipment, used at locomotives LE 060 EA of 5100 kW, we considered the EP3 type of pantograph as model. This was modelled at scale 1:1 taking into account the placement on the body of the locomotive. For the simulation of wind we considered three point values of its speed (10 m/s, 20 m/s, 30 m/s) and angle of eight values that are within the range of 0 deg – 180 deg. With the results of the simulation we have done a comparative analysis on the additional vertical forces introduced by wind for the cases analyzed.

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