scholarly journals The effect of crosswinds on ride comfort in high speed trains running on curves

DYNA ◽  
2015 ◽  
Vol 82 (194) ◽  
pp. 46-51 ◽  
Author(s):  
Miguel Aizpun Navarro ◽  
Ignacio Sesma Gotor

The effect of crosswinds on the risk of railway vehicles overturning has been a major issue ever since manufacturers began to produce lighter vehicles that run at high speeds. However, ride comfort can also be influenced by crosswinds, and this effect has not been thoroughly analyzed. This article describes the effect of crosswinds on ride comfort in high speed trains when running on curves and for several wind velocities under a Chinese hat wind scenario, which is the scenario recommended by the standard. Simulation results show that the combination of crosswinds and the added stiffness of the lateral bumpstop on the secondary suspension can become a significant source of instability, leading to flange-to-flange contact and greatly jeopardizing ride comfort. Moreover, this comfort problem is an issue even when the wheel unloading ratio is well below the standard’s limits and vehicle safety can be guaranteed.

2006 ◽  
Vol 321-323 ◽  
pp. 1589-1592 ◽  
Author(s):  
Young Guk Kim ◽  
Seog Won Kim ◽  
Chan Kyoung Park ◽  
Kyoung Ho Moon ◽  
Tae Won Park

Evaluation of the ride comfort for railway vehicles can be divided into two classes; the long-term evaluation of ride comfort and the momentary evaluation of ride comfort. In the present paper, the ride comfort of railway vehicles are investigated for high speed trains in Korea. The long-term ride comfort has been analyzed by a statistical method and the momentary ride comfort has been analyzed by using the longitudinal acceleration, the jerk and the stationary lateral acceleration.


Author(s):  
H. Farahpour ◽  
D. Younesian ◽  
E. Esmailzadeh

Ride comfort of high-speed trains is studied using Sperling's comfort index. Dynamic model is developed in the frequency domain and the power spectral density (PSD) of the body acceleration is obtained for four classes of tracks. The obtained acceleration PSD is then filtered using Sperling's filter. The effects of the rail roughness and train speed on the comfort indicators are investigated. A parametric study is also carried out to evaluate the effects of the primary and secondary suspension systems on the comfort indicators.


2020 ◽  
Author(s):  
Patrícia Filipa Pinheiro da Silva ◽  
Joaquim Mendes

Trains are becoming a popular way of transportation driven by comfort and ecology reasons. Latest statistics showed an increasing of 40% on the number of passengers in the last decade. The development of new high-speed trains promoted an evolution on the coaches interiors, as to make railway transportation more attractive. To cope this objective, new requirements were set, namely high levels of comfort and safety. In complement, multiple long-term ride comfort evaluation methods have been developed. The aim of this work is to present a review on the passengers’ comfort perception    in railway vehicles. The standards ISO 2631, EN 12299 and the Sperling’s method are the most used ones. They refer several factors, as the vibration (level, frequency and duration), temperature, noise and area of the train per capita. Additionally, the perception of reduced accidents delayed the studies of passive security. Therefore, recent works focus on reducing the consequences of the second impact in case of accident and minimize the biomechanics injury criterion, through new interiors design layouts. Keywords: Railway vehicles, Passengers comfort, Posture, Ride evaluation, Passive safety


Volume 2 ◽  
2004 ◽  
Author(s):  
M. H. Kargarnovin ◽  
D. Younesian ◽  
D. J. Thompson ◽  
C. J. C. Jones

The ride comfort of high-speed trains passing over railway bridges is studied in this paper. The effects of some nonlinear parameters in a carriage-track-bridge system are investigated such as the load-stiffening characteristics of the rail-pad and the ballast, rubber elements in the primary and secondary suspensions systems. The influence of the track irregularity and train speed on two comfort indicators, namely Sperling’s comfort index and the maximum acceleration level, are also studied. Timoshenko beam theory is used for modelling the rail and bridge and two layers of parallel damped springs in conjunction with a layer of mass are used to model the rail-pads, sleepers and ballast. A randomly irregular vertical track profile is modelled, characterised by a power spectral density (PSD). The ‘roughness’ is generated for three classes of tracks. Nonlinear Hertz theory is used for modelling the wheel-rail contact.


2018 ◽  
Vol 166 ◽  
pp. 02002 ◽  
Author(s):  
Jonghyup Lee ◽  
Seibum Choi

While many vehicle control systems focus on vehicle safety and vehicle performance at high speeds, most driving conditions are very low risk situations. In such a driving situation, the ride comfort of the vehicle is the most important performance index of the vehicle. Electro mechanical brake (EMB) and other brake-by-wire (BBW) systems have been actively researched. As a result, braking actuators in vehicles are more freely controllable, and research on improving ride comfort is also possible. In this study, we develop a control algorithm that dramatically improves ride comfort in low risk braking situations. A method for minimizing the inconvenience of a passenger due to a suddenly changing acceleration at the moment when the vehicle is stopped is presented. For this purpose, an acceleration trajectory is generated that minimizes the discomfort index defined by the change in acceleration, jerk. A controller is also designed to track this trajectory. The algorithm that updates the trajectory is designed considering the error due to the phase lag occurring in the controller and the plant. In order to verify the performance of this controller, simulation verification is completed using a car simulator, Carsim. As a result, it is confirmed that the ride comfort is dramatically improved.


Author(s):  
Young Guk Kim ◽  
Seog Won Kim ◽  
Chan Kyoung Park ◽  
Kyoung Ho Moon ◽  
Tae Won Park

Author(s):  
Arun K. Samantaray ◽  
Smitirupa Pradhan

Running times of high-speed rolling stock can be reduced by increasing running speed on curved portions of the track. During curving, flange contact causes large lateral force, high frequency noises, flange wears and wheel load fluctuation at transition curves. To avoid derailment and hunting, and to improve ride comfort, i.e., to improve the curving performances at high speed, forced/active steering bogie design is studied in this chapter. The actively steered bogie is able to negotiate cant excess and deficiency. The bogie performance is studied on flexible irregular track with various levels of cant and wheel wear. The bogie and coach assembly models are developed in Adams VI-Rail software. This design can achieve operating speed up to 360 km/h on standard gauge ballasted track with 150mm super-elevation, 4km turning radius and 460m clothoid type entry curve design. The key features of the designed bogie are the graded circular wheel profiles, air-spring secondary suspension, chevron springs in the primary suspension, anti-yaw and lateral dampers, and the steering linkages.


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