Effect of Independently Rotating Wheels on the Dynamic Performance of Railroad Vehicles

2007 ◽  
Author(s):  
Khaled E. Zaazaa ◽  
Brian Whitten
Keyword(s):  
Dynamic Performance ◽  
Equations Of Motion ◽  
Lateral Force ◽  
Ride Quality ◽  
Vehicle Dynamic ◽  
Vehicle Performance ◽  
Railroad Vehicles ◽  
Judicious Choice ◽  
Wheel Profile ◽  
Railroad Vehicle

In recent decades, there has been a considerable effort in improving railroad vehicle dynamic performance. This involves high operational speed with stable behavior, better curving performance, better ride quality, and increased life of the wheel and rail profiles. To achieve this goal, the use of independently rotating wheels (IRW) is proposed as one potential option. Using IRW either partially or totally decouples the pitch rotation of the two wheels of the “wheelset”, thereby reducing or eliminating the longitudinal creepage and thus wheelset hunting motion. On the other hand, the longitudinal creepage is no longer available to provide steering assistance in curves, and continuous flange contact during curving is expected. However, by judicious choice of wheel profile and careful truck design, the lateral force between wheel and rail during curving can be reduced, decreasing the wear on both the wheel and rail profiles. Therefore, such solution is assumed to achieve higher stable operational speed and improved curving behavior. In this paper, the effect of using IRW on railroad vehicle performance is examined. The equations of motion of a single wheelset model and a suspended wheelset model that use IRW are presented and compared with those for similar models that use a rigid wheelset. Using a newly developed general multibody code, a complete vehicle model that uses IRW is examined and compared with one that uses rigid wheelsets. The effect of the IRW system on vehicle dynamic performance is quantitatively presented. In addition, the ability of the contact formulations used in this multibody code for modeling the IRW system is confirmed.

Effect of Wheel-Rail Contact Geometry Relationship on Vehicle Dynamic Performance

2013 ◽  
Vol 712-715 ◽  
pp. 1541-1544
Author(s):  
Yi Jia Wang ◽  
Jing Zeng
Keyword(s):  
High Speed ◽  
Rapid Development ◽  
Dynamic Performance ◽  
Vehicle Dynamic ◽  
Safe Operation ◽  
Rail Wear ◽  
Variation Characteristics ◽  
Wheel Profile ◽  
Wheel Profile Wear ◽  
High Speed Vehicle

With the rapid development of high-speed railways, wheel and rail wear has become increasingly serious due to the acute wheel-rail interaction. During the operation of high speed vehicle, complicated wheel-rail contact force will lead to wheel profile wear, which will worsen the dynamic performance of vehicle system, or even influence the safe operation of vehicles. In order to ensure the vehicle dynamic performance, right now regularly wheel re-profiling has to be adopted. Therefore, the study of wheel profile wear and its effect on vehicle dynamic performance is very important [1,. The purpose of the paper is to study the variation characteristics of vehicle dynamic performance with respect to the wheel profile wear through numerical simulation and field test.

Influence of Wheel-Rail Profiles on the Hunting Vibrations of Rail Vehicle Trucks

1985 ◽  
Vol 107 (2) ◽  
pp. 167-174 ◽  
Author(s):  
A. F. D’Souza ◽  
W-J. Tsung
Keyword(s):  
Dynamic Performance ◽  
Equations Of Motion ◽  
Algebraic Equations ◽  
Wheel Wear ◽  
Hunting Behavior ◽  
Describing Functions ◽  
High Acceleration ◽  
Nonlinear Algebraic Equations ◽  
Wheel Profile ◽  
Freight Trucks

The effect of several wheel and rail profiles on the hunting behavior of three-piece North American freight truck is investigated by the method of describing functions. After replacing the nonlinear terms by their equivalent describing functions, the differential equations of motion are converted to a set of coupled nonlinear algebraic equations which are then solved by the Newton-Raphson method. It is shown that the wearing of the rail profile has a significant adverse effect on the dynamic behavior. It greatly lowers the critical speed for the onset of hunting and raises the frequency, thereby causing high acceleration levels. It is also shown that the modified Heumann wheel profile exhibits a superior dynamic performance for freight trucks than the standard new wheel profile used in North America. The effects of wheel wear and loads on hunting are also investigated.

Rigid ring with Bouc–Wen tire model for vehicle dynamic analysis

2016 ◽  
Vol 231 (19) ◽  
pp. 3530-3540
Author(s):  
SD Na ◽  
DW Park ◽  
WS Yoo
Keyword(s):  
Dynamic Response ◽  
Equations Of Motion ◽  
Test System ◽  
Ride Quality ◽  
Tire Model ◽  
Vehicle Dynamic ◽  
Static State ◽  
Rigid Ring ◽  
Vehicle Dynamic Simulation ◽  
Suspension Model

Tires are one of the main automobile components that affect driving performance and ride quality. The rigid ring tire model had been widely used to characterise a vehicle rolling over uneven road surfaces. The stiffness of an rigid ring tire is calculated in the quasi-static state; however, this model is limited in its ability to represent the dynamic response of a tire. In this study, a Bouc–Wen type force element was included in the rigid ring tire model to enhance the dynamic response of a tire, and the effectiveness of the proposed rigid ring with Bouc–Wen model was demonstrated. To validate the proposed rigid ring with Bouc–Wen tire model, two experiments were performed. The first one was performed using a flat-trac test system, and the second one was a full-car test performed over a single cleat by using accelerometers and velocity sensors. For the vehicle dynamic simulation, the equations of motion of the vehicle were established using a functional suspension model defined in terms of the kinematic and compliance characteristics of the wheel and chassis. The simulation results obtained using the proposed rigid ring with Bouc–Wen tire model were compared with the experimental results, which showed both efficiency and accuracy of the propsed model.

Eigenvalue Analysis of Multibody Models of Railroad Vehicles Including Track Flexibility

2011 ◽  
Author(s):  
Jose´ L. Escalona ◽  
Rosario Chamorro ◽  
Antonio M. Recuero
Keyword(s):  
Vehicle Dynamics ◽  
Equations Of Motion ◽  
Steady Motion ◽  
Differential Algebraic Equations ◽  
Eigenvalue Analysis ◽  
Ride Quality ◽  
Algebraic Equations ◽  
Essential Information ◽  
Railroad Vehicles ◽  
The Stability

The stability analysis of railroad vehicles using eigenvalue analysis can provide essential information about the stability of the motion, ride quality or passengers comfort. The system eigenvalues are not in general a vehicle property but a property of a vehicle travelling steadily on a periodic track. Therefore the eigenvalue analysis follows three steps: calculation of steady motion, linearization of the equations of motion and eigenvalue calculation. This paper deals with different numerical methods that can be used for the eigenvalue analysis of multibody models of railroad vehicles that can include deformable tracks. Depending on the degree of nonlinearity of the model, coordinate selection or the coordinate system used for the description of the motion, different methodologies are used in the eigenvalue analysis. A direct eigenvalue analysis is used to analyse the vehicle dynamics from the differential-algebraic equations of motion written in terms of a set of constrained coordinates. In this case not all the obtained eigenvalues are related to the dynamics of the system. As an alternative the equations of motion can be obtained in terms of independent coordinates taking the form of ordinary differential equations. This procedure requires more computations but the interpretation of the results is straightforward.

scholarly journals Influence of Wheel Profile Wear Coupled with Wheel Diameter Difference on the Dynamic Performance of Subway Vehicles

2021 ◽  
Vol 2021 ◽  
pp. 1-15
Author(s):  
H. X. Li ◽  
A. H. Zhu ◽  
C. C. Ma ◽  
P. W. Sun ◽  
J. W. Yang ◽  
...  
Keyword(s):  
Dynamic Response ◽  
Contact Force ◽  
Ride Comfort ◽  
Dynamic Performance ◽  
Lateral Force ◽  
Dynamics Modeling ◽  
Derailment Coefficient ◽  
Wheel Profile ◽  
Wheel Profile Wear ◽  
Wear Index

In view of the coexistence of wheel profile wear (WPW) and wheel diameter difference (WDD) on an actual subway line, a dynamic analysis method based on coupling between WPW and equivalent in-phase WDD was proposed. Based on the measurements from a subway vehicle in operation on this line, dynamics modeling and calculations were performed for a single carriage of this vehicle. Later, the interaction between the effects of WPW and equivalent in-phase WDD on the vehicle dynamic performance was analyzed, and the dynamic response in the presence of coupled damage was compared between the outer and inner wheels. Furthermore, the difference in the dynamic response caused by different positions of the larger-diameter wheels (i.e., on the inner track or outer track) was analyzed for the case where equivalent in-phase WDD occurred between the front and rear bogies. The results show that when the vehicle ran on a straight line, the coupling between WPW and WDD reduced the vehicle’s stability but improved its ride comfort. When the vehicle traveled on a curved line, it showed reductions in the lateral wheel/rail contact force, derailment coefficient, axle lateral force, and wear index if the outer wheels had a larger diameter. As a result, the deterioration of the vehicle’s dynamic performance due to the increasing degree of WPW slowed down, and its curve negotiation performance improved. Meanwhile, the outer wheels had significantly greater lateral wheel/rail contact force, derailment coefficient, and wear index compared to the inner wheels. When a −1 mm WDD was coupled with the worn wheel profile for 14 × 104 kilometers traveled, the dynamic performance indexes of the vehicle were close to or even exceeded the corresponding safety limits. The findings can provide technical support for subway vehicle maintenance.

A Study of the Wheel Geometry Effect on the Dynamic Behavior of Railroad Vehicles

2005 ◽  
Author(s):  
Ahmed A. Shabana ◽  
Mahmoud Tobaa ◽  
Khaled E. Zaazaa
Keyword(s):  
Critical Speed ◽  
Single Point ◽  
Vehicle Stability ◽  
Point Contacts ◽  
Vehicle Model ◽  
Geometric Properties ◽  
Railroad Vehicles ◽  
Wheel Profile ◽  
The Stability ◽  
Railroad Vehicle

The effect of the geometry of a wheel profile that allows only a single point of contact between the wheel and the rail is investigated in this study. The local geometric properties of this profile are compared with the local geometric properties of a profile that allows for two-point contacts in order to understand the basic differences between the two profiles. A simple model is first used to examine the effect of the profile geometry on the stability and nonlinear dynamics of a suspended wheel set. The results obtained in this paper show that the wheel profile can significantly alter the critical speed. Using surface parameters that define the wheel and rail geometry, the global representations of the positions of the points on the wheel and rail surfaces are obtained and used to define the conditions of the contact between the wheel and the rail. Numerical results are presented for a full railroad vehicle model and the effect of the wheel profile on the vehicle stability is investigated. A comparison between the results obtained using the two wheel profiles in the case of wheel climb scenarios is presented.

Description of Methods for the Eigenvalue Analysis of Railroad Vehicles Including Track Flexibility

2012 ◽  
Vol 7 (4) ◽  
Author(s):  
José L. Escalona ◽  
Rosario Chamorro ◽  
Antonio M. Recuero
Keyword(s):  
Vehicle Dynamics ◽  
Equations Of Motion ◽  
Steady Motion ◽  
Differential Algebraic Equations ◽  
Eigenvalue Analysis ◽  
Ride Quality ◽  
Algebraic Equations ◽  
Essential Information ◽  
Railroad Vehicles ◽  
The Stability

The stability analysis of railroad vehicles using eigenvalue analysis can provide essential information about the stability of the motion, ride quality, or passengers’ comfort. The eigenvalue analysis follows three steps: calculation of steady motion, linearization of the equations of motion, and eigenvalue calculation. This paper deals with different numerical methods that can be used for the eigenvalue analysis of multibody models of railroad vehicles that can include deformable tracks. Depending on the degree of nonlinearity of the model and coordinate selection, different methodologies can be used. A direct eigenvalue analysis is used to analyze the vehicle dynamics from the differential-algebraic equations of motion written in terms of a set of constrained coordinates. As an alternative, the equations of motion can be obtained in terms of independent coordinates taking the form of ordinary differential equations. This procedure requires more computations, but the interpretation of the results is straightforward.

scholarly journals Examination of Vehicle Performance at High Speed and High Cant Deficiency

2011 ◽  
Author(s):  
Brian Marquis ◽  
Jon LeBlanc ◽  
Ali Tajaddini
Keyword(s):  
High Speed ◽  
Lateral Force ◽  
Ride Quality ◽  
High Speed Rail ◽  
Vehicle Performance ◽  
Track Geometry ◽  
Track Maintenance ◽  
Performance Requirements ◽  
Rail Vehicles ◽  
The Us

In the US, increasing passenger speeds to improve trip time usually involves increasing speeds through curves. Increasing speeds through curves will increase the lateral force exerted on track during curving, thus requiring more intensive track maintenance to maintain safety. These issues and other performance requirements including ride quality and vehicle stability, can be addressed through careful truck design. Existing high-speed rail equipment, and in particular their bogies, are better suited to track conditions in Europe or Japan, in which premium tracks with little curvature are dedicated for high-speed service. The Federal Railroad Administration has been conducting parametric simulation studies that examine the performance of rail vehicles at high speeds (greater than 90 mph) and at high cant deficiency (greater than 5 inches). The purpose of these analyses is to evaluate the performance of representative vehicle designs subject to different combinations of track geometry variations, such as short warp and alinement.

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