Research on Bogie Frame Lateral Instability of High-Speed Railway Vehicle

In order to find out the reason for the bogie frame instability alarm in the high-speed railway vehicle, the influence of wheel tread profile of the unstable vehicle was investigated. By means of wheel-rail contact analysis and dynamics simulation, the effect of tread wear on the bogie frame lateral stability was studied. The result indicates that the concave wear of tread is gradually aggravated with the increase of operation mileage; meanwhile the wheel-rail equivalent conicity also increases. For the rail which has not been grinded for a long time, the wear of gauge corner and wide-worn zone is relatively severe; the matching equivalent conicity is 0.31-0.4 between the worn rail and the concave-worn-tread wheel set. The equivalent conicity between the grinded rail and the concave-worn tread is below 0.25; the equivalent conicities are always below 0.1 between the reprofiled wheel set and various rails. The result of the line test indicates that the lateral acceleration of bogie frame corresponding to the worn wheel-rail can reach 8.5m/s2, and the acceleration after the grinding is reduced below 4.5m/s2. By dynamics simulation, it turns out that the unreasonable wheel-rail matching relationship is the major cause of the bogie frame lateral alarm. With the tread-concave wear being aggravated, the equivalent conicity of wheel-rail matching constantly increases, which leads to the bogie frame lateral instability and then the frame instability alarm.

Download Full-text

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

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.321-323.1593 ◽

2006 ◽

Vol 321-323 ◽

pp. 1593-1596 ◽

Cited By ~ 1

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.

Download Full-text

On the Planning and Construction of Railway Curved Track

International Journal of Vehicle Structures and Systems ◽

10.4273/ijvss.13.2.04 ◽

2021 ◽

Vol 13 (2) ◽

Author(s):

Sono Bhardawaj ◽

Rakesh Chandmal Sharma ◽

Sunil Kumar Sharma ◽

Neeraj Sharma

Keyword(s):

High Speed ◽

Time Derivative ◽

Railway Track ◽

Lateral Acceleration ◽

Transition Curve ◽

Railway Vehicle ◽

Geometric Conditions ◽

Curve Track ◽

Curved Track ◽

Transition Curves

Increasing demand for railway vehicle speed has pushed the railway track designers to develop high-quality track. An important measure of track quality is the character of the transition curve track connecting different intersecting straight tracks. A good transition curve track must be able to negotiate the intermittent stresses and dynamic effects caused by changes in lateral acceleration at high speed. This paper presents the constructional methods for planning transition curves considering the dynamics of movement. These methods consider the non-compensated lateral acceleration, deviation in lateral acceleration and its higher time derivatives. This paper discusses the laying methods of circular, vertical and transition curves. Key aspects in laying a curved track e.g. widening of gauge on curves are discussed in this paper. This paper also suggests a transition curve which is effective not only from a dynamic point of view considering lateral acceleration and its higher time derivative but also consider the geometric conditions along with the required deflection angle.

Download Full-text

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

Proceedings of the Institution of Mechanical Engineers Part F Journal of Rail and Rapid Transit ◽

10.1177/0954409718789531 ◽

2018 ◽

Vol 233 (2) ◽

pp. 220-236 ◽

Cited By ~ 3

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.

Download Full-text