A Practical Model of Rail Vehicle Curve Negotiation

1981 ◽  
Vol 10 (2-3) ◽  
pp. 117-119
Author(s):  
P. P. MARCOTTE ◽  
K. J. R. MATHEWSON ◽  
R. YOUNG
Keyword(s):  
Rail Vehicle ◽  
Practical Model ◽  
Curve Negotiation

Integration of Geometry and Analysis for the Study of Liquid Sloshing in Vehicle System Dynamics

2017 ◽  
Author(s):  
Brynne Nicolsen ◽  
Huailong Shi ◽  
Liang Wang ◽  
Ahmed A. Shabana
Keyword(s):  
Rigid Body ◽  
Vehicle Dynamics ◽  
Three Dimensional ◽  
Rigid Body Dynamics ◽  
Liquid Sloshing ◽  
Inertia Force ◽  
Vehicle Stability ◽  
Vehicle Model ◽  
Rail Vehicle ◽  
Curve Negotiation

Commonly-used sloshing models are either unable to capture changes in the continuous distribution of the fluid free surface, or are not suited for the integration with high fidelity computational multibody system (MBS) algorithms. The objective of this investigation is to address this deficiency by developing a new continuum-based liquid sloshing approach that accounts for the effect of complex fluid and tank geometry and can be systematically integrated with MBS algorithms in order to allow for studying complex motion scenarios. A unified geometry/analysis mesh is used from the outset to examine the effect of liquid sloshing on railroad and highway vehicle dynamics during various maneuvers including braking and curve negotiation [1,2]. Using a non-modal approach, the geometry of the tank and fluid is accurately defined, a continuum-based fluid constitutive model is developed, and a fluid-tank contact algorithm using the penalty approach is employed. In order to examine the effect of liquid sloshing on vehicle dynamics during curve negotiation, a general and precise definition of the outward inertia force is defined, which for flexible bodies does not take the simple form used in rigid body dynamics. During maneuvers, the liquid may experience large displacements and significant changes in shape that can be captured effectively using absolute nodal coordinate formulation (ANCF) finite elements. For rail systems, the liquid sloshing model is integrated with a three-dimensional MBS vehicle algorithm, in which the three-dimensional wheel/rail contact force formulation is used to account for the longitudinal, lateral, and spin creep forces that influence vehicle stability. The effects of fluid sloshing on vehicle dynamics in the case of a tank partially filled with liquid are studied and compared with the equivalent rigid body model in braking and curve negotiation. The results obtained in the study of the rail vehicle model show that liquid sloshing can exacerbate the unbalance effects when the rail vehicle negotiates a curve at a velocity higher than the balance speed, and can significantly increase coupler forces during braking. Analysis of the highway vehicle model shows that the liquid sloshing changes the contact forces between the tires and the ground — increasing the forces on certain wheels and decreasing the forces on other wheels — which in cases of extreme sloshing, can negatively impact the vehicle stability by increasing the possibility of wheel lift and vehicle rollover.

Analysis on Curve Negotiation Ability of the Rail Vehicle Based on SIMPACK

2013 ◽  
Vol 721 ◽  
pp. 551-555 ◽  
Author(s):  
Li Hua Wang ◽  
An Ning Huang ◽  
Guang Wei Liu
Keyword(s):  
Dynamic Performance ◽  
Lateral Force ◽  
Lateral Stability ◽  
Rail Vehicle ◽  
Body Dynamics ◽  
Curve Track ◽  
The Stability ◽  
Multi Body ◽  
Body Dynamic ◽  
Curve Negotiation

The curve negotiation ability and lateral stability are the important and contradictory indicators when evaluating the dynamic performance of the rail vehicle. And in order to study the stability of the rail vehicle, its curve negotiation ability will be studied firstly. In this paper, the whole multi-body dynamic model of the rail vehicle was proposed based on the theory of multi-body dynamics in the software of Simpack. And the lateral force, derailment and overturning coefficient of the rail vehicle when it passed through a specific curve track with specific speed. Then the curve negotiation ability of the rail vehicle was estimated accurately.

Rail Passenger Vehicle Lateral Dynamic Performance Improvement Through Active Control

1978 ◽  
Vol 100 (4) ◽  
pp. 270-283 ◽  
Author(s):  
P. K. Sinha ◽  
D. N. Wormley ◽  
J. K. Hedrick
Keyword(s):  
Active Control ◽  
High Speed ◽  
Ride Quality ◽  
Vehicle Speed ◽  
Tracking Errors ◽  
Vehicle Performance ◽  
Control Power ◽  
Rail Vehicle ◽  
Performance Reduction ◽  
Curve Negotiation

High speed operation of conventional rail vehicles is limited by a number of dynamic problems including ride quality, curve negotiation, and hunting. Active control is investigated as a technique for improving rail vehicle performance at high speeds. An automatic controller of specified configuration and structure is defined based on the physics of the wheel-rail interaction dynamics which allow a decomposition of dynamic constraints into selected frequency bands and a methodology for selecting the controller parameters is presented. Two controller case studies are examined to demonstrate the effectiveness of controller configuration on rail vehicle performance in terms of ride quality and tracking errors on tangent track while allowing specified curve negotiation requirements to be met. Estimates of control power requirements are also obtained which show that the controller configurations considered produce improvements in vehicle performance—reduction of rms vehicle accelerations by a factor of between 5 and 6 and reduction of rms tracking errors by a factor of between 4 and 5—with modest expenditures of control—power between 1.5 and 2 kw per truck at a vehicle speed of 68.58m/s.

Leadership, morality and ethics: Developing a practical model for moral decision-making

2018 ◽  
Author(s):  
Alfred W. Kaszniak ◽  
Cynda H. Rushton ◽  
Joan Halifax
Keyword(s):  
Decision Making ◽  
Applied Ethics ◽  
Moral Decision ◽  
Moral Decision Making ◽  
Contemplative Science ◽  
Practical Model

The present paper is the product of collaboration between a neuroscientist, an ethicist, and a contemplative exploring issues around leadership, morality, and ethics. It is an exploration on how people in roles of responsibility can better understand how to engage in discernment processes with more awareness and a deeper sense of responsibility for others and themselves. It draws upon recent research and scholarship in neuroscience, contemplative science, and applied ethics to develop a practical understanding of how moral decision-making works and is essential in this time when there can seem to be an increasing moral vacuum in leadership.

Contemporary Methods of Designing Rail Vehicle Running Systems with the Use of CAD and CAM Solutions

2020 ◽  
Vol 64 (187) ◽  
pp. 75-80
Author(s):  
Tomasz Antkowiak ◽  
Marcin Kruś
Keyword(s):  
System Design ◽  
Preliminary Design ◽  
Support Design ◽  
Detailed Design ◽  
Final Shape ◽  
Rail Vehicle ◽  
Design Engineers ◽  
Running System ◽  
Cad Cam

The article discusses the process of designing the running system of a rail vehicle using CAD and CAM tools as the solutions supporting the process. It describes the particular stages of design taking its final shape: from a preliminary design, through a detailed design, ending with the stage of production. Each stage includes a presentation of how CAD and CAM tools are used to support design engineers in their practice. Keywords: running system, design, CAD, CAM

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