Accurate Representation of the Rail Geometry for Multibody System Applications

2009 ◽  
Vol 5 (1) ◽  
Author(s):  
Brian Marquis ◽  
Khaled E. Zaazaa ◽  
Tariq Sinokrot ◽  
Ahmed A. Shabana

The objective of this study is to examine the geometric description of the spiral sections of railway track systems, in order to correctly define the relationship between the geometry of the right and left rails. The geometry of the space curves that define the rails are expressed in terms of the geometry of the space curve that defines the track center curve. Industry inputs such as the horizontal curvature, grade, and superelevation are used to define the track centerline space curve in terms of Euler angles. The analysis presented in this study shows that, in the general case of a spiral, the profile frames of the right and left rails that have zero yaw angles with respect to the track frame have different orientations. As a consequence, the longitudinal tangential creep forces acting on the right and left wheels, in the case of zero yaw angle, are not in the same direction. Nonetheless, the orientation difference between the profile frames of the right and left rails can be defined in terms of a single pitch angle. In the case of small bank angle that defines the superelevation of the track, one can show that this angle directly contributes to the track elevation. The results obtained in this study also show that the right and left rail longitudinal tangents can be parallel only in the case of a constant horizontal curvature. Since the spiral is used to connect track segments with different curvatures, the horizontal curvature cannot be assumed constant, and as a consequence, the right and left rail longitudinal tangents cannot be considered parallel in the spiral region. Numerical examples that demonstrate the effect of the errors that result from the assumption that the right and left rails in the spiral sections have the same geometry are presented. The numerical results obtained show that these errors can have a significant effect on the quality of the predicted creep contact forces.

Author(s):  
Brian Marquis ◽  
Khaled E. Zaazaa ◽  
Tariq Z. Sinokrot ◽  
Ahmed A. Shabana

The objective of this study is to examine the geometric description of the spiral sections of railway track systems in order to correctly define the relationship between the geometry of the right and left rails. The geometry of the space curves that define the rails are expressed in terms of the geometry of the space curve that defines the track center curve. Industry inputs such as the horizontal curvature, grade, and super-elevation are used to define the track centerline space curve in terms of Euler angles. The analysis presented in this study shows that, in the general case of a spiral, the profile frames of the right and left rails that have zero yaw angle with respect to the track frame have different orientations. As a consequence, the longitudinal tangential creep forces acting on the right and left wheels, in the case of zero yaw angle, are not in the same direction. Nonetheless, the orientation difference between the profile frames of the right and left rails can be defined in terms of a single pitch angle. In the case of small bank angle that defines the super-elevation of the track, one can show that this angle directly contributes to the track elevation. The results obtained in this study also show that the right and left rail longitudinal tangents can be parallel only in the case of a constant horizontal curvature. Since the spiral is used to connect track segments with different curvatures, the horizontal curvature can not be assumed constant, and as a consequence, the right and left rail longitudinal tangents can not be considered parallel in the spiral region. Numerical examples that demonstrate the effect of the errors that result from the assumption that the right and left rail in the spiral sections have the same geometry are presented. The numerical results obtained show that these errors can have a significant effect on the quality of the predicted creep contact forces.


2018 ◽  
Vol 4 (2) ◽  
pp. 89
Author(s):  
Peshraw A. Mohammed Ameen

Power is the legitimate use of force in a socially acceptable manner, the legitimate force exercised by a person or group over others. The element of legitimacy is an important element of the idea of ​​power, which is the primary means by which power distinguishes itself from other, more general concepts of force. Force can be imposed forcibly or violently. On the other hand, the Authority relies on the acceptance of the subordinates, granting the right to those above them to issue orders or directives. the relationship of psychology and political power is a strong relationship, and through the study of the psychology of the masses and rulers in any state or region can be interpreted and predict the behavior of power and the masses in this country, and the subject of authority in the Kurdistan region as a subject directly related to the subject of psychology of power and the quality of this authority in this region is a place Controversy for everyone who monitors and deals with this power, so determine the quality of power and how to conduct it through the study of the psychology of power, according to current reality and one of the most important jobs for researchers in the Kurdistan Region so we know the quality of political authority in this region, so we try in this modest research to determine the quality and type of power in the Kurdistan Region through the analysis of the psychology of power in Kurdistan region.


Author(s):  
J. P. Pascal ◽  
J. Berger ◽  
F. Bondon ◽  
C. Clerc ◽  
S. Teppe

This paper presents the Online Calculation of Railway Elastic Contacts (OCREC), a dynamic railway calculation tool based on an advanced contact kernel, and its coupling with the MSC ADAMS multi-body commercial software. The OCREC contact kernel is used as a subroutine of multi-body codes in order to calculate contact forces between wheelsets and rails. The OCREC method is “online” as it not only redefines new contact parameters at each time step but also determines all simultaneous contacts on each wheel as allowed by Hertz Elasticity theory. From the normal forces and relative velocities given by the Hertz theory, Tangential Forces are calculated using Kalker’s FASTSIM (modified for elliptical pressure distribution). After a description of the OCREC theory, the paper presents the linkage between OCREC and MSC ADAMS software. OCREC calculates contact forces within a Frenet frame (oxyz) following the track layout where ox is tangent to the track; oy is horizontal and oz normal to oxy. As ADAMS calculates inside a different frame, and as it has no built-in track system, it was necessary to develop a program capable of connecting 3 different frames: the ‘dummy’ track frame, the Frenet frame and the fixed ADAMS frame. Note that the ‘dummy’ frame is directly calculated from railway track curvature measurements recorded in so-called ‘space curves’. The OCREC ADAMS link is first validated by a bogie rolling on a dummy track. With the equations of the OCRECYM code established directly within the “dummy” frame, the OCREC-ADAMS results are compared to a specific OCRECYM validation code. Then, the results from an actual railway case are presented: behavior of one coach is calculated on a real measured track including curves and defaults. During the following step, the OCREC-ADAMS results are compared to OCRECYM results. After some model updating for adjustment to physical properties of elastic joints (helicoidal springs), a good correlation is obtained between the codes. The analysis of the different force and displacement components proves this kind of numerical tool’s capabilities of assessing the railway vehicle’s dynamic behavior. Especially, the Y/Q safety ratio is well calculated. Thus, the OCREC contact kernel, which is powerful for complex contact topologies such as conformal contacts, and necessary for high speed safety calculation, can be used as a subroutine of standard multi-body software, giving it high capabilities for dynamic railway calculation.


2014 ◽  
Vol 3 (03) ◽  
Author(s):  
Rohana Handaningrum ◽  
Rr. Amanda Pasca Rini

Abstract. This study aims to determine the relationship of perception of the quality of candidates and political trust with political participation. The population in this study were students at the University August 17, 1945 Surabaya who already have the right to vote or voting rights (age> 17 years or married). While the sample in this study was 150 students, with incidental sampling method. The results of this study were analyzed using multiple regression analysis and resulted in: 1) The relationship between perceptions of quality candidates (candidates) and political beliefs (political trust) with political participation, the value of F = 1.056 with a significance level of 0.351> 0.05. It can be concluded that this hypothesis is rejected or not proven, that means there is no significant relationship between perceptions of quality candidates (candidates) and political beliefs (Political Trust) with Political Participation. 2) partial test results perceptions of the quality of candidates (X1) with political participation, the value of t = 0.297 and 0.767 significance level> 0.05. This suggests that partial perception of the quality factor candidates (candidates) (X1), there was no significant relationship to political participation (Y). It can be concluded that this hypothesis is not proven or rejected. 3) The results of the partial test of political beliefs (political trust) (X2) with political participation, the value of t = -1.424 and a significance level of 0.157> 0.05. This suggests that partial political trust factor (X2) there is no significant relationship to political participation (Y). value of R Square (R2) of 0.14. R Square value of 0.14 indicates the percentage contribution of the effect of independent variables (perception of the quality of candidates and political beliefs) on the dependent variable (political participation) only by 1.4%, while the remaining 98.6% is influenced by other variables not variables included in the study. Keywords : Perception of the quality of candidates, Political trust, Political participation.


2007 ◽  
Vol 56 (6) ◽  
Author(s):  
Marianna Gensabella Furnari

L’impostazione classica della questione bioetica dell’eutanasia attraverso il paradigma dei principi conduce a risolvere la questione con un sì, se si privilegia il principio di autonomia, o con un no se si dà il primato al principio dell’indisponibilità della vita. Il saggio muove dalla proposta che sia possibile un altro approccio, basato sull’interazione, suggerita come linea metodica da Warren T. Reich, del paradigma dei principi con gli altri paradigmi della bioetica: l’esperienza, la cura, la virtù. Il primo momento è ripensare l’eutanasia come l’oggetto di una domanda che viene dalla sofferenza e che, come tale, va accolta ed interpretata in un contesto di relazione. A differenza del suicidio, non vi è qui un darsi la morte, ma un domandare la morte all’altro. L’attenzione etica va spostata dal far centro esclusivamente sull’autonomia al focalizzarsi anche e soprattutto sulla relazione, in particolare sulla complessità e le contraddizioni che segnano oggi la relazione tra il paziente e il medico. Anche se chiede una “cura” limite, paradossale che non può essere data, pena la contraddizione e il ribaltamento degli stessi fini della medicina, la domanda di eutanasia non può restare inevasa, ma deve essere accolta, ri-aperta con l’attenzione che il paradigma di cura impone, con l’humanitas che il paradigma di virtù ci consegna. L’attenzione etica all’esperienza di chi domanda la morte diviene il primo momento per trovare una conciliazione tra momenti apparentemente antitetici, come la sacralità e la qualità della vita, per cogliere la complementarità tra diritti apparentemente antitetici come il diritto ad essere lasciati soli e il diritto a non essere lasciati soli, per sostenere insieme la liberazione dal dolore fisico e la liberazione del dolore dell’anima. Spostando il punto di vista dalla libertà alla relazione, il saggio vuole indicare l’impossibilità etica di dire di sì all’eutanasia proprio sul versante della relazione, ponendo al tempo stesso l’accento non solo sulla responsabilità che il dire di sì comporta, ma anche sulle altre responsabilità di cui la domanda di eutanasia ci fa carico: le responsabilità che riguardano la situazione da cui trae origine, e le altre che riguardano ciò che rimane da fare per rispondere alla richiesta di aiuto e di cura che la domanda sottende. Con il movimento proprio dell’etica della cura, il saggio vuole proporre di non risolvere il dilemma in cui la questione bioetica dell’eutanasia sembra costringerci, rinunciando alla vita o alla libertà, ma di provare a ridefinire il contesto da cui il dilemma ha origine, in modo tale che sia possibile tenere insieme vita e libertà. ---------- Classical approach to the problem of the euthanasia, through the paradigm of the principles conducts to solve the matter with a yes, if the principle of autonomy is privileged, or with a no if the primacy is given to the principle of the unavailability of the life. This paper moves from the proposal that another approach is possible, based on the interaction, suggested as methodic line by Warren T. Reich, of the paradigm of the principles with the other paradigms of the bioethics: the experience, the care, the virtue. The first moment is to consider the euthanasia as the object of a question that comes from the suffering and that, as such, it must be welcomed and interpreted in a context of relationship. Unlike the suicide there is not here a killing oneself, but an asking other for death. The ethical attention must be moved from the exclusive center of autonomy to the relationship, particularly on the complexity and the contradictions that mark the physician-patient relationship between today. Even if it asks a limit “care”, paradoxical that cannot be given, or the aims of the medicine itself would be contradicted and overturned, the question of euthanasia cannot stay outstanding, but must be welcomed, opened again with the attention that the paradigm of care imposes, with the humanitas that the paradigm of virtue delivers us. The ethical attention to the experience of whom asks the death it becomes the first moment to find a conciliation among apparently antithetical moments, as the sacredness and the quality of the life, to gather the complementarity among apparently antithetical rights as the right to be left alone and the right not to be left alone, to sustain together the liberation from the physical pain and the liberation from the pain of the soul. Moving the point of view from freedom to relationship the paper wants to point out the ethical impossibility to say yes to the euthanasia just on the side of the relationship, at the same time setting the accent not only on the responsibility that saying yes means, but also on the other responsibilities of which the question of euthanasia ask us: the responsibilities derived by the situation and the others concerning what to answer to the help request and care that the question subtends. In the way proper of the ethics of the care, the paper proposes not to solve the dilemma of the euthanasia abdicating to the life or to the liberty, but trying to redefine the context from which the dilemma has origin, in such way that it is possible to hold together life and liberty.


1991 ◽  
Vol 29 (1) ◽  
pp. 1-2

It is important to take medicines in the right dose, at the right times, by the right route and in the right way (e.g. with food), and doctors and pharmacists should be able to give the clear advice which patients need. It is the quality of the relationship between the patient and the doctor and pharmacist, including mutual respect and understanding, that will help the patient to follow the recommendations. The term ‘compliance’ is used to describe how well the patient does this, but it is an authoritarian word which denies the patient’s autonomy. Treatment is an activity shared by doctor and patient in which both parties should ‘comply’ with the needs of the other. In this article we therefore use ‘compliance’ only as a technical term.


2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Carli Friedman

The United Nations exclaims "all human beings have the right to be treated with dignity and respect" (Annan, 2005, p. 34). Yet, disabled people have long been denied respect in the United States and have been subjected to disability oppression and ableism. For these reasons, the aim of this study was to explore the relationship between respect and disability, particularly respect's impact on the quality of life of disabled people. We had two research questions: (1.) what factors predict disabled people being respected? and, (2.) how does being respected impact the quality of life of disabled people? To explore these questions, we used secondary Personal Outcome Measures® data from approximately 1,500 disabled people; we analyzed this data to examine relationships between disabled people's interpretations of feeling and being respected, and their quality of life. Our findings revealed being respected had a significant impact on every area of ones' quality of life. Problematically, this also included areas which should be considered non-negotiable fundamental human and civil rights, that should not depend on if, and how, people respect disabled people. While the attitudes underlying the disrespect of disabled people are harmful and problematic, human and civil rights should be inalienable – ones' access to exercise their rights, to safety, to health, and to many other domains should not depend on others' attitudes about, and treatment toward, you.


2018 ◽  
Vol 7 (2.26) ◽  
pp. 7
Author(s):  
K David ◽  
R Anand

You cannot control what you can’t measure - Tom DeMarco -Metrics plays a critical role in any industry. The metrics can tell the senior management the health of the activity in that organization. In the paper, we have studied the relationship between the metrics and the quality of deliverables. Once the right metrics are identified for a particular phasein the life cycle model it will help the project manager to proactive-ly detect the issues earlier and arrest the defects. This can help the project teams to deliver the product on time without defects. There by the cost of the projects can be reduced which in turn will have high customer satisfaction.  


2019 ◽  
Vol 48 (1) ◽  
pp. 76-88
Author(s):  
András Farkas

The worldwide increase in frequency of traffic for passenger trains and the rise of freight trains over the recent years necessitate the more intense deployment of track monitoring and rail inspection procedures. The wheel-rail contact forces, induced by the static axle loads of the vehicle and the dynamic effects of ground-borne vibration coming from the track superstructure, have been a significant factor contributing to the degradation of the railway track system. Measurements of track irregularities have been applied since the early days of railway engineering to reveal the current condition and quality of railway lines. Track geometry is a term used to collectively refer to the measurable parameters including the faults of railway tracks and rails. This paper is aiming to review the characteristics of compact inertial measurement systems (IMUs), their components, installation, the basic measures of the quality of the track using motion sensors, like accelerometers, gyroscopes and other sensing devices mounted on different places of the vehicle. Additionally, the paper briefly discusses the fundamentals of inertial navigation, the kinematics of the translational and rotational train motions to obtain orientation, velocity and position information.


Author(s):  
M. Dean Havron ◽  
Robert A. Westin

A plan was developed for evaluation of the relationship between ride and ride quality of vehicles currently used in public transportation systems and new prototypes. The components of ride as the physical environment and ride quality as passenger response were defined and articulated. Three settings were recommended for conduct of research: a simulator, rides by captive passengers, and rides by revenue passengers. A procedure was described for the implementation of experimental studies. Key features involved accumulations of a growing data bank describing ride-ride quality relationships and forecasting results of future experiments from the data bank. An experiment was conducted in the NASA Langley simulator to examine the relationships between ride vibrations derived from actual railway track signatures and ride quality as rated by subjects. When the design was replicated, comfort ratings by subjects were highly reliable. Subjects could discriminate between stimulus amplitudes for continuous rough track and diamond crossings; they could not discriminate amplitude variations well for roll. These data fail to show that subjects can discriminate well between the different types of vibration that define ride.


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