scholarly journals Suppression of vertical bending and rigid-body-mode vibration in railway vehicle car body by primary and secondary suspension control: Results of simulations and running tests using Shinkansen vehicle

2009 ◽  
Vol 223 (6) ◽  
pp. 517-531 ◽  
Author(s):  
Y Sugahara ◽  
A Kazato ◽  
R Koganei ◽  
M Sampei ◽  
S Nakaura
Keyword(s):  
Rigid Body ◽  
Ride Comfort ◽  
Ride Quality ◽  
Railway Vehicle ◽  
Quality Level ◽  
Bending Vibration ◽  
Car Body ◽  
Rigid Body Mode ◽  
Bending Mode ◽  
Mode Vibration

To improve ride comfort in railway vehicles, the suppression of vertical bending vibration and rigid-body-mode vibration in the car body is essential. In this paper, a system is proposed that aims to reduce bending and rigid-body-mode vibration simultaneously by introducing damping control devices in the primary and secondary suspensions. The technique involves a control system of primary vertical dampers and air springs; the former are used to suppress the first bending mode vibration; the latter, to suppress the rigid-body-mode vibration. The results of both simulations and vehicle running tests on the Sanyo—Shinkansen line demonstrate that this system reduced vertical vibrations in the bogies and the car body using the sky-hook control theory. In the running tests in particular, the system reduced the vertical vibration acceleration PSD peak value in the first bending mode to almost 20 per cent and in the rigid body mode to almost 50 per cent compared with the case when the system was not used. As a result, the ride quality level LT (a widely used index of ride comfort in Japan) decreased by at least 3 dB, indicating greater ride comfort.

scholarly journals An examination of alternative schemes for active and semi-active control of vertical car-body vibration to improve ride comfort

2021 ◽  
pp. 095440972110221
Author(s):  
Bin Fu ◽  
Stefano Bruni
Keyword(s):  
Ride Comfort ◽  
Control Strategies ◽  
Three Dimensional ◽  
Ride Quality ◽  
Vehicle Model ◽  
Bending Vibration ◽  
Conventional Vehicle ◽  
Car Body ◽  
Model Based ◽  
Bending Modes

The recent tendency to reduce the weight of car bodies is posing a new challenge to vertical ride quality, since the vibrations related to car-body vertical bending modes affect heavily passengers’ comfort and cannot be fully mitigated by conventional vehicle suspensions. In this work, four mechatronic suspensions, considering active and semi-active technologies in secondary and primary suspensions, are compared to show their relative merits. LQG and H∞ model-based control strategies are established in a consistent way for each suspension scheme to perform a comparative assessment of the four concepts on objective grounds. A two-dimensional 9-DOF vehicle model is firstly built, using a simplified representation of car-body bending modes; this model is also used to design the model-based controllers. The comparison of the four mechatronic suspension schemes based on the 9-DOF model shows that full-active secondary suspension is the most effective solution whilst semi-active primary suspension is also effective in terms of mitigating car-body bending vibration. Then, a three-dimensional flexible multibody system (FMBS) vehicle model integrated with a finite-element car-body is considered to allow a more detailed consideration of the vehicle’s vibrating behaviour. The results of the FMBS model show a good agreement to the results of the 9-DOF model and the relative merits of the four mechatronic suspension schemes as found from the previous analysis are basically confirmed, although the FMBS model is more suited for a quantitative assessment of ride quality.

scholarly journals Influence of Bending Vibration on the Vertical Vibration Behaviour of Railway Vehicles Carbody

2021 ◽  
Vol 11 (18) ◽  
pp. 8502
Author(s):  
Mădălina Dumitriu ◽  
Ioana Izabela Dihoru
Keyword(s):  
Ride Comfort ◽  
Reference Points ◽  
Structural Vibration ◽  
Railway Vehicle ◽  
Type Model ◽  
Vertical Acceleration ◽  
Bending Vibration ◽  
Railway Vehicles ◽  
Bending Mode ◽  
Vertical Vibrations

The topic of reducing structural vibrations in the case of flexible carbodies of railway vehicles has been intensively studied, but it is still an active research topic thanks to the importance of the perspective of improving the ride comfort. However, no study has been identified in the specialty literature to feature the contribution of the vibration structural modes upon the vibration behaviour of the railway vehicle carbody. The structural vibration modes of the flexible carbodies are particularly complex; however, the first vertical bending mode holds great significance in terms of the ride comfort. This paper analyses the influence of the first vertical bending mode on the vibration behaviour in three reference points of the railway vehicle carbody in correlation with the carbody flexibility, the vehicle velocity and the suspension damping. This study relies on comparisons between the results of the numerical simulations obtained for a ‘flexible carbody’ type model of the vehicle and the ones obtained for a ‘rigid carbody’ type model. The first part of this study analyses the characteristics of the vertical vibrations behaviour of the flexible carbody based on the dynamic response of the vehicle and expressed as the acceleration power spectral density. In the second part, the influence of the vertical bending on the vertical vibrations level of the carbody is analysed using the root mean square of the vertical acceleration.

scholarly journals A numerical and scaled experimental study on ride comfort enhancement of a high-speed rail vehicle through optimizing traction rod stiffness

2020 ◽  
pp. 107754632096192
Author(s):  
Vahid Bokaeian ◽  
Mohammad Ali Rezvani ◽  
Robert Arcos
Keyword(s):  
Rigid Body ◽  
High Speed ◽  
Degrees Of Freedom ◽  
Ride Comfort ◽  
Ride Quality ◽  
Railway Vehicle ◽  
Equivalent Linearization ◽  
Scaled Model ◽  
Rail Vehicle ◽  
Optimal Stiffness

In this research, the effect of rail vehicle carbody’s flexural modes on the ride comfort of an example high-speed railway vehicle is investigated. The vehicle is modeled as a rigid multi-body system, where the rigid body vertical, longitudinal, pitch, and roll degrees of freedom of the carbody and bogie frames and the rigid body vertical and roll degrees of freedom of the wheelsets are considered. An Euler–Bernoulli beam theory is used to account for the flexural motion of the carbody. The longitudinal interaction between carbody and bogie through the traction rod is modeled as a nonlinear spring element. The corresponding equations of motion of the system in the frequency domain are obtained by using the equivalent linearization method. The effect of the traction rod is explored by using this model. Also, the optimal stiffness of the traction rod element that minimizes the flexural vibrations of the carbody is obtained through a genetic algorithm. With the optimal stiffness for the traction rod, the ride quality index at the center of the carbody floor is improved by 41% at a speed of 300 km/h. For the validation of numerical results, a scaled model of the vehicle with a scale factor of 24.5 was constructed, and its associated results are presented. The model was excited by random input signals, which were generated based on the power spectral density of the track irregularity function. The agreement between the simulation results and the scaled experimental outcome when compared with the measured data from other sources is found to be satisfactory. In the framework of the physical scaled model, the filtering effect due to the vehicle bogie base is also examined.

Lateral Dynamics Optimization of a Conventional Railcar

1975 ◽  
Vol 97 (3) ◽  
pp. 293-299 ◽  
Author(s):  
N. K. Cooperrider ◽  
J. J. Cox ◽  
J. K. Hedrick
Keyword(s):  
Constrained Optimization ◽  
High Speed ◽  
Optimization Problem ◽  
Ride Comfort ◽  
Stability Margin ◽  
Railway Vehicle ◽  
Constrained Optimization Problem ◽  
Stroke Length ◽  
Car Body ◽  
Unconstrained Problem

The attempt to develop a railway vehicle that can operate in the 150 to 300-mph(240 to 480-km/h) speed regime is seriously hampered by the problems of ride comfort, curve negotiation, and “hunting.” This latter phenomena involves sustained lateral oscillations that occur above certain critical forward velocities and cause large dynamic loads between the wheels and track as well as contributing to passenger discomfort. This paper presents results of an initial effort to solve these problems by utilizing optimization procedures to design a high speed railway vehicle. This study indicates that the problem is more easily treated as a constrained optimization problem than as an unconstrained problem with several terms in the objective function. In the constrained optimization problem, the critical “hunting” speed was maximized subject to constraints on 1) the acceleration of the car body, 2) the suspension stroke length, and 3) the maximum suspension stroke while negotiating a curve. A simple, three degree-of-freedom model of the rail vehicle was used for this study. Solutions of this constrained problem show that beyond a minimum yaw stiffness between truck and car body the operating speed remains nearly constant. Thus, above this value, the designer may trade off yaw stiffness, wheel tread conicity and stability margin.

Model Predictive Control Application to Flexible-Bodied Railway Vehicles for Vibration Suppression

2013 ◽  
Vol 10 ◽  
pp. 25-35
Author(s):  
P.E. Orukpe
Keyword(s):  
Model Predictive Control ◽  
Predictive Control ◽  
High Speed ◽  
Ride Comfort ◽  
The Body ◽  
Ride Quality ◽  
Linear Matrix ◽  
Railway Vehicle ◽  
Railway Vehicles ◽  
Effective Manner

In this paper, we apply model predictive control (MPC) based on mixed H2/H to active vibration control of the flexibility of railway vehicle to improve ride quality. However, the flexibility in the body of high-speed railway vehicles creates difficulties which in practice may result in the body structure being heavier than what it is supposed to be. The use of active suspension helps to model the vehicle and its flexibility in an effective manner. Conventional control approaches are compared with linear matrix inequality MPC technique using flexible-bodied railway vehicle as an example. The result indicates that the MPC technique performs better in improving ride comfort compared to the passive and classical techniques when flexible modes are present.

Ride comfort of a higher speed rail vehicle using a magnetorheological suspension system

2017 ◽  
Vol 232 (1) ◽  
pp. 32-48 ◽  
Author(s):  
Sunil Kumar Sharma ◽  
Anil Kumar
Keyword(s):  
Ride Comfort ◽  
Suspension System ◽  
Magnetorheological Damper ◽  
Ride Quality ◽  
Railway Vehicle ◽  
Passive Suspension ◽  
Railway Vehicles ◽  
Rail Vehicle ◽  
Passive Suspension System ◽  
Secondary Suspension

In a railway vehicle, vibrations are generated due to the interaction between wheel and track. To evaluate the effect of vibrations on the ride quality and comfort of a passenger vehicle, the Sperling's ride index method is frequently adopted. This paper focuses on the feasibility of improving the ride quality and comfort of railway vehicles using semiactive secondary suspension based on magnetorheological fluid dampers. Equations of vertical, pitch and roll motions of car body and bogies are developed for an existing rail vehicle. Moreover, nonlinear stiffness and damping functions of passive suspension system are extracted from experimental data. In view of improvement in the ride quality and comfort of the rail vehicle, a magnetorheological damper is integrated in the secondary vertical suspension system. Parameters of the magnetorheological damper depend on current, amplitude and frequency of excitations. Three semi-active suspension strategies with magnetorheological damper are analysed at different running speeds and for periodic track irregularity. The performance indices calculated at different semi-active strategies are juxtaposed with the nonlinear passive suspension system. Simulation results establish that magnetorheological damper strategies in the secondary suspension system of railway vehicles reduce the vertical vibrations to a great extent compared to the existing passive system. Moreover, they lead to improved ride quality and passenger comfort.

Study on Improving the Ride Comfort in Railway Vehicles Using Anti-Bending Dampers

2018 ◽  
Vol 880 ◽  
pp. 207-212 ◽  
Author(s):  
Mădălina Dumitriu
Keyword(s):  
Numerical Simulations ◽  
Ride Comfort ◽  
Railway Vehicle ◽  
Vehicle Model ◽  
Bending Vibrations ◽  
Bending Vibration ◽  
Type Method ◽  
Railway Vehicles

The paper researches the possibility to reduce the bending vibrations in the railway vehicle carbody and to improve the ride comfort via a new passive type method. This would involve the fitting of the vehicle with dampers, called anti-bending dampers, fixed to the longitudinal beams of a carbody underframe. The efficiency of this method is made visible in the results derived from numerical simulations developed on the basis of a rigid-flexible coupled vehicle model. The introduction of the anti-bending dampers is seen as a significant reduction in the bending vibration of the carbody. Similarly, a relevant improvement of the ride comfort at the centre of the carbody, at high velocities. This efficiency mainly depends on the damping constant of the anti-bending damper.

A Review on Dynamic Analysis of Rail Vehicle Coach

2018 ◽  
Vol 10 (3) ◽  
Author(s):  
S. Palli ◽  
R. Koona ◽  
S.K. Sharma ◽  
R.C. Sharma
Keyword(s):  
Dynamic Analysis ◽  
Dynamic Behaviour ◽  
Ride Comfort ◽  
Probabilistic Approach ◽  
Design Parameters ◽  
Railway Vehicle ◽  
Transient Dynamic Analysis ◽  
Car Body ◽  
Power Spectral ◽  
Forced Vibration Analysis

Railway vehicle is one of the rigorously developing passenger and goods carrier in the past few centuries. Dynamic behaviour of the railway coach is a vital aspect in its design and also in terms of passenger safety and ride comfort. Dynamic response includes both deterministic and probabilistic analyses. Modal, harmonic and transient dynamic analysis is part of deterministic analyses, whereas random response using spectrum methods and power spectral density (PSD) is a probabilistic approach. This paper is an attempt to cover various modelling and simulation methods of the railway bogie and coach adopted by various researchers to understand the dynamic behaviour of the railway coach. Further, the research findings of various dynamic parameters obtained theoretically and practically against different inputs like sinusoidal and random inputs to the car body have been discussed. This forms a basis in understanding the development of railway coach design when one is interested in carrying out free and forced vibration analysis on the coach, as well as assists to optimize various design parameters of components like bogie, car body and suspension elements in terms of vehicle dynamics.

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