scholarly journals Numerical Investigation into the Critical Speed and Frequency of the Hunting Motion in Railway Vehicle System

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Jianfeng Sun ◽  
Maoru Chi ◽  
Wubin Cai ◽  
Xuesong Jin
Keyword(s):  
High Speed ◽  
Critical Speed ◽  
Dynamic Performance ◽  
Decisive Role ◽  
Creep Model ◽  
Railway Vehicle ◽  
Sudden Increase ◽  
Nonlinear Creep ◽  
Vehicle System ◽  
Hunting Frequency

The critical speed and hunting frequency are two basic research objects of vehicle system dynamics and have a significant influence on the dynamic performance. A lateral dynamic model with 17 degrees of freedom was established in this study to investigate the critical speed and hunting frequency of a high-speed railway vehicle. The nonlinearities of wheel/rail contact geometry, creep forces, and yaw damper were all considered. A heuristic nonlinear creep model was employed to estimate the contact force between the wheel and the rail. The Maxwell model, which covers the influence of the stiffness characteristic, is used to simulate the yaw damper. To reflect the blow-off of the yaw damper, the damping coefficient is described by stages. Based on the mathematical model, the combined effects of vehicle parameters on the critical speed in the straight line and hunting frequency of the wheelset were investigated innovatively. The novel phenomenon that the hunting frequency exhibits a sudden increase from a smaller value to a larger value when the blow-off of the yaw damper occurs was discovered during the calculations. The extents to which various parameters affect the critical speed and hunting frequency are clear on the basis of the numerical results. Moreover, all of the parameter values were divided into three sections to determine the sensitive range for the critical speed and hunting frequency. The results show that the first section of values plays the decisive role on both the critical speed and the hunting frequency for all parameters analyzed. The investigation in this paper enriches the study of hunting stability and gives some ideas to probably solve the abnormal vibrations during the actual operation.

Hunting Stability Analysis of a New High-Speed Railway Vehicle Model Moving on Curved Tracks

2007 ◽  
Author(s):  
Yung-Chang Cheng ◽  
Sen-Yung Lee
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Lateral Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Nonlinear Creep ◽  
Car Body ◽  
Suspension Parameters ◽  
Virtual Boundary ◽  
Hunting Stability

A new dynamic model of railway vehicle moving on curved tracks is proposed. In this new model, the motion of the car body is considered and the motion of the tuck frame is not restricted by a virtual boundary. Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a fourteen degrees of freedom car system, considering the lateral displacement and the yaw angle of the each wheelset, the truck frame and the car body, moving on curved tracks are derived in completeness. To illustrate the accuracy of the analysis, the limiting cases are examined. In addition, the influences of the suspension parameters on the critical hunting speeds evaluated via the linear and the nonlinear creep models respectively are studied. Furthermore, the influences of the suspension parameters on the critical hunting speeds evaluated via the fourteen degrees of freedom car system and the six degrees of freedom truck system, which the motion of the tuck frame is restricted by a virtual boundary, are compared.

Derailment Analysis of High-Speed Railway Vehicle Bogies

2011 ◽  
Vol 110-116 ◽  
pp. 186-195 ◽  
Author(s):  
Yung Chang Cheng ◽  
Chern Hwa Chen ◽  
Che Jung Yang
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Vertical Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Bogie Frame ◽  
Suspension Parameters ◽  
Yaw Angle

Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a 12 degree-of-freedom (12-DOF) bogie system which takes account of the lateral displacement, vertical displacement, the roll angle and the yaw angle of the each wheelset and the bogie frame, moving on curved tracks are derived. The nonlinear creep forces and moments are constructed via the saturation constant of the nonlinear creep model in completeness. The effect of the suspension parameters of a bogie system on the derailment quotient is investigated. Results obtained in this study show that the derailment quotient of a bogie system increases as the vehicle speed increases. In addition, the derailment quotient of a bogie system is generally decreased with the increasing values of suspension parameters.

Dynamic Analysis for Derailment Safety of High-Speed Railway Vehicle Bogies

2011 ◽  
Vol 199-200 ◽  
pp. 239-242
Author(s):  
Chern Hwa Chen ◽  
Yung Chang Cheng ◽  
Shun Chin Yang ◽  
Yuh Yi Lin ◽  
Cheng Hsin Chang ◽  
...  
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Vertical Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Suspension Parameters ◽  
Derailment Safety ◽  
Yaw Angle

Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a 12 degree-of-freedom (12-DOF) bogie system which takes account of the lateral displacement, vertical displacement, the roll angle and the yaw angle of the each wheelset and the bogie frame, moving on curved tracks are derived. The nonlinear creep forces and moments are constructed via the saturation constant of the nonlinear creep model in completeness. The effect of the suspension parameters of a bogie system on the derailment quotient is investigated. Results obtained in this study show that the derailment quotient of a bogie system increases as the vehicle speed increases. In addition, the derailment quotient of a bogie system is generally decreased with the increasing values of suspension parameters.

Nonlinear Analysis on Hunting Stability for High-Speed Railway Vehicle Trucks on Curved Tracks

2004 ◽  
Vol 127 (4) ◽  
pp. 324-332 ◽  
Author(s):  
Sen-Yung Lee ◽  
Yung-Chang Cheng
Keyword(s):  
High Speed ◽  
Lateral Displacement ◽  
Vertical Displacement ◽  
Degree Of Freedom ◽  
Creep Model ◽  
Railway Vehicle ◽  
Nonlinear Creep ◽  
Hunting Stability ◽  
Six Degree Of Freedom ◽  
Yaw Angle

Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of a ten-degree-of-freedom truck system, considering the lateral displacement, the vertical displacement, the roll and yaw angles of the each wheelset, and the lateral displacement and yaw angle of the truck frame, moving on curved tracks, are derived in completeness. To illustrate the accuracy of the analysis, the limiting cases are examined. The influences of the suspension parameters, including those losing in the six-degree-of-freedom system, on the critical hunting speeds evaluated via the linear and nonlinear creep models, respectively, are studied and compared.

The Use of Uniform Design and Nelder-Mead Simplex Methods to Optimization of Suspension Parameters of a High Speed Railway Vehicle System

2012 ◽  
Vol 488-489 ◽  
pp. 1257-1262
Author(s):  
Yung Chang Cheng ◽  
Cheng Kang Lee
Keyword(s):  
High Speed ◽  
Uniform Design ◽  
Performance Measure ◽  
Optimization Process ◽  
Creep Model ◽  
Railway Vehicle ◽  
Second Phase ◽  
High Speed Railway ◽  
Suspension Parameters ◽  
Vehicle System

This paper has proposed an optimization process with two phases to optimize suspension parameters of a high speed railway vehicle for advancing system’s robustness and performance. The vehicle’s nonlinear coupled differential equations of motion with fourteen degrees of freedom are created based on Kalker’s linear theory and the heuristic nonlinear creep model. The performance measure of the vehicle system is critical hunting speed, which is determined by Lyapunov’s indirect method. The first phase of optimization is to execute a set of experiments which is planned based on uniform design method. The second phase of optimization is to apply the Nelder-Mead Simplex method to exploit the best solution obtained in the first phase. Finally, the presented optimization process can effectively not only advance the performance of the vehicle system but also increase the performance’s robustness.

A New Dynamic Model of High-Speed Railway Vehicle Moving on Curved Tracks

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Sen-Yung Lee ◽  
Yung-Chang Cheng
Keyword(s):  
Dynamic Model ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Lateral Displacement ◽  
Creep Model ◽  
Railway Vehicle ◽  
Nonlinear Creep ◽  
Six Degrees Of Freedom ◽  
Car Body ◽  
Yaw Angle

A new dynamic model of railway vehicle moving on curved tracks is proposed. In the new model, the motion of the car body is considered and the motion of the truck frame is not restricted by a virtual boundary. Based on the heuristic nonlinear creep model, the nonlinear coupled differential equations of the motion of an eight degrees of freedom car system—considering the lateral displacement and the yaw angle of each wheelset, the truck frame, and the half car body—moving on curved tracks are derived completely. To illustrate the accuracy of the analysis, the limiting cases are examined. It is shown that the influence of the gyroscopic moment of the wheelsets on the critical hunting speed is negligible. In addition, the influences of the suspension parameters, including those losing in the six degrees of freedom system, on the critical hunting speeds evaluated via the linear and the nonlinear creep models are studied and compared.

scholarly journals Influence of suspension parameter for derailment analysis of a full railway vehicle model cruising on a curved track

2021 ◽  
Author(s):  
Yamika Patel ◽  
◽  
Vikas Rastogi ◽  
Wolfgang Borutzky ◽  
◽  
...  
Keyword(s):  
High Speed ◽  
Research Work ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Pitch Motion ◽  
Proposed Model ◽  
Curved Track ◽  
Creep Models

The main intention of this research work is to study the derailment response of high speed railway vehicle (HSRV) cruising on a curved track. In previous research work, lower degree of freedom (DOF) has been considered for the derailment analysis which may not give more accurate results. Hence, a 31 DOF bondgraph model of HSRV has been developed which consist of carbody, two truck frames and two selfsame wheelsets for each truck frame. Vertical, lateral, roll, yaw and pitch motion are considered for carbody and bogie and except pitch motion all the other motion are considered for wheelsets. Non-linearities in terms of heuristic nonlinear creep model and flange contact has been employed to simulate the derailment response at high speed. The effect of vehicle speed running on a curved track was investigated for derailment quotient. The main aim of present research work to evaluate derailment quotient at the speed range of 150 kmph to 600 kmph for hard and soft suspension parameter. Derailment quotient has been calculated for both linear and nonlinear creep models and it is seen that DQ for linear model has a lower value compare to non linear creep. The major advantages of the proposed model are that, the presented model can actively predict the derailment of a railway vehicle, and also precisely determine the nonlinear critical hunting speeds.

Wheel nominal rolling radius difference on hunting stability of railway vehicle system under a speed-dependent nonlinear creep model

2017 ◽  
Vol 24 (14) ◽  
pp. 3107-3123
Author(s):  
Yung-Chang Cheng ◽  
Po-Hsien Wu
Keyword(s):  
Degrees Of Freedom ◽  
Creep Model ◽  
Railway Vehicle ◽  
Vehicle Speed ◽  
Nonlinear Creep ◽  
Original Design ◽  
Vehicle System ◽  
Wheel Radius ◽  
Hunting Stability ◽  
Stiffness And Damping

This study presents the hunting stability of a railway vehicle system in a speed-dependent nonlinear creep model with varying wheel conicity and nominal rolling radius. Integrating Kalker’s linear theory, Hertz contact theory, and the heuristic nonlinear creep model, the speed-dependent nonlinear creep model, including the semi-axis lengths and nonconstant creep coefficients with the varying vehicle speed, is investigated. Modeling and dynamic analysis are performed in the 28 degrees-of-freedom railway vehicle system. Lyapunov’s indirect method is used to calculate critical hunting speed of a railway vehicle system. The effects of suspension system parameters, various wheel conicities, and nominal rolling radii on the hunting stability are illustrated and compared. Critical hunting speeds calculated for the original design wheel are consistently better than those obtained from worn wheels with differences in wheel conicity and wheel rolling radius. Notably, critical hunting speeds calculated for a softer stiffness and damping decrease as wheel nominal rolling radius difference increases. Furthermore, the critical hunting speed calculated by the harder stiffness and damping increase as wheel nominal rolling radius difference increases. Analysis of hunting stability further shows that vehicle running speed must be considered when the wheel nominal rolling radius is less than the origin design wheel radius. Therefore, the effects of various wheel nominal rolling radius differences on hunting stability is an important research issue.

A Study on the Method of Vibration Analysis for Korean High Speed Train by the On-Line Test

2006 ◽  
Vol 321-323 ◽  
pp. 1593-1596 ◽  
Author(s):  
Chan Kyoung Park ◽  
Ki Whan Kim ◽  
Jin Yong Mok ◽  
Young Guk Kim ◽  
Seog Won Kim
Keyword(s):  
Vibration Analysis ◽  
High Speed ◽  
Vibration Mode ◽  
Dynamic Performance ◽  
Railway Vehicle ◽  
High Speed Train ◽  
Acceleration Data ◽  
On Line ◽  
System Vibration ◽  
Line Test

The Korean High Speed Train (KHST) has been tested on the Kyongbu high speed line and the Honam conventional line since 2002. A data acquisition system was developed to test and prove the dynamic performance of the KHST, and the system has been found to be very efficient in acquiring multi-channel data from accelerometers located all over the train. Also presented in this paper is an analysis procedure which is simple and efficient in analyzing the acceleration data acquired during the on-line test of the KHST. The understanding of system vibration mode for a railway vehicle is essential to evaluate the characteristics of a dynamic system and to diagnose the dynamic problems of the vehicle system during tests and operations. Methods based on homogeneous linear systems are not realistic because real systems have nonlinear characteristics and are strongly dependent on environmental conditions. In this paper an efficient method of vibration analysis has been proposed and applied for the KHST to evaluate its vibration mode characteristics. The results show that this method is suitable to estimate the system vibration modes of the KHST.

Modelling and evaluation of the hunting behaviour of a high-speed railway vehicle on curved track

2018 ◽  
Vol 233 (2) ◽  
pp. 220-236 ◽  
Author(s):  
Vivek Kumar ◽  
Vikas Rastogi ◽  
PM Pathak
Keyword(s):  
High Speed ◽  
Degrees Of Freedom ◽  
Critical Speed ◽  
Transportation Network ◽  
Graph Model ◽  
Railway Vehicle ◽  
Physical Damage ◽  
Creep Theory ◽  
High Speed Railway ◽  
Hunting Behaviour

Nowadays, rail transport is a very important part of the transportation network for any countries. The demand for high operational speed makes hunting a very common instability problem in railway vehicles. Hunting leads to discomfort and causes physical damage to carriage components, such as wheels, rails, etc. The causes of instability and derailment should be identified and eliminated at the designing stage of a train to ensure its safe operation. In most of the earlier studies on hunting behaviour, a simplified model with a lower degree of freedom were considered, which resulted in incorrect results in some instances. In this study, a complete bond graph model of a railway vehicle with 31 degrees of freedom is presented to determine the response of a high-speed railway vehicle. For this purpose, two wheel–rail contacts grounded on a flange contact and Kalker’s linear creep theory are implemented. The model is simulated to observe the effects of suspension elements on the vehicle’s critical hunting velocity. It is observed that the critical hunting speed is extremely sensitive to the primary longitudinal and lateral springs. Other primary and secondary springs and dampers also affect the critical speed to some extent. However, the critical hunting velocity is insensitive to vertical suspension elements for both the primary and secondary suspensions. Also, the critical speed is found to be inversely related to the conicity of the wheel.

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