Correlation between Ride Comfort Index and Sperling's Index for Evaluation Ride Comfort in Railway Vehicles

2018 ◽  
Vol 880 ◽  
pp. 201-206 ◽  
Author(s):  
Mădălina Dumitriu ◽  
Mihai Leu
Keyword(s):  
Numerical Simulations ◽  
Critical Points ◽  
Reference Point ◽  
Ride Comfort ◽  
Dynamic Performance ◽  
Railway Vehicles ◽  
Comfort Index ◽  
Index Methods ◽  
Comfort Indices

Ride comfort is a reference point in evaluating the dynamic performance in railway vehicles. There are more methods to assess the ride comfort, depending on the traffic details and the specific needs of a railway administration. This paper focuses on the comfort index methods, in accordance with UIC Leaflet 513 R and the standard of railway applications ENV 12299, and the ride Sperling’s method, formulated by Sperling. A correlation is drawn between the comfort indices corresponding to the two methods, based on the link between the comfort and the values of these indices. The comfort indices derived from the two methods by numerical simulations help with validating the fact that, in general, the velocity influences the vertical ride comfort, and, in particular, the position of the carbody critical points, from the perspective of the ride comfort.

scholarly journals Influences of Carbody Vertical Flexibility on Ride Comfort of Railway Vehicles

2017 ◽  
Vol 64 (2) ◽  
pp. 219-238 ◽  
Author(s):  
Mădălina Dumitriu ◽  
Cătălin Cruceanu
Keyword(s):  
Dynamic Response ◽  
Numerical Simulations ◽  
Ride Comfort ◽  
Reference Points ◽  
Railway Vehicles ◽  
Comfort Index ◽  
Traction System ◽  
Selection Of

Abstract The article investigates the influence of the carbody vertical flexibility on the ride comfort of the railway vehicles. The ride comfort is evaluated via the comfort index calculated in three reference points of the carbody. The results of the numerical simulations bring attention to the importance of the carbody symmetrical vertical bending upon the dynamic response of the vehicle, mainly at high velocities. Another conclusion is that the ride comfort can be significantly affected as a function of the symmetrical bending frequency of the carbody. Similarly, there are improvement possibilities for the ride comfort when the best selection of the stiffness in the longitudinal traction system between the carbody and bogie and the vertical suspension damping is made.

Correlation of ride comfort evaluation methods for railway vehicles

2003 ◽  
Vol 217 (2) ◽  
pp. 73-88 ◽  
Author(s):  
Y-G Kim ◽  
H-B Kwon ◽  
S-W Kim ◽  
C-K Kim ◽  
T-W Kim
Keyword(s):  
Evaluation Method ◽  
Ride Comfort ◽  
Dynamic Performance ◽  
Evaluation Methods ◽  
Railway Vehicles ◽  
Comfort Evaluation ◽  
Vibration Model ◽  
Ride Comfort Evaluation ◽  
Abundant Data ◽  
Comfort Indices

Ride comfort is one of the most important dynamic performance characteristics of railway vehicles and is affected by various factors, such as vibration, acoustic sound, smell, temperature, visual stimuli, humidity and seat design. In general, vibration is known to be a major factor that affects ride comfort. There are many studies on methods for evaluating ride comfort in railway vehicles, and many standards or criteria have been developed and used in many countries. Most of the evaluation methods, however, recommend different evaluation methods and criteria, so users should carefully choose a ride comfort evaluation method and must examine whether it can be applied to their railway vehicles or not. The present study has looked at relationships between several evaluation methods using a vibration model resulting from frequency analysis and statistical analysis of acceleration measurements of railway vehicles. The present vibration model yields abundant data for correlation of the ride comfort indices, resulting in reliable relations between the ride comfort indices.

scholarly journals Study on the Evaluation Methods of the Vertical Ride Comfort of Railway Vehicle—Mean Comfort Method and Sperling’s Method

2021 ◽  
Vol 11 (9) ◽  
pp. 3953
Author(s):  
Mădălina Dumitriu ◽  
Dragoș Ionuț Stănică
Keyword(s):  
Numerical Simulations ◽  
Ride Comfort ◽  
Original Model ◽  
Railway Vehicle ◽  
Type Model ◽  
Factors Affecting ◽  
Comfort Index ◽  
Vertical Vibrations ◽  
Secondary Suspension ◽  
Comfort Indices

The paper herein analyzes the ride comfort at the vertical vibrations of the railway vehicle, evaluated by two methods—mean comfort method and Sperling’s method. The two methods have in common that the estimation of the comfort sensation is conducted with the comfort indices, namely ride comfort index NMVZ and ride comfort index Wz. The values of these indices are derived from numerical simulations. The advantage of using the results of the numerical simulations versus using experimental results, on which most previous research is based, resides in the fact that the ride comfort indices can be examined while taking into account the influence of velocity and certain parameters altering the behavior of vertical vibrations of the carbody, i.e., carbody flexibility and the suspension damping. The numerical simulation applications have been developed based on a theoretical model of the vehicle that considers important factors affecting the behavior of vertical vibrations of the carbody, by means of a ‘flexible carbody’ type model and an original model of the secondary suspension. The results presented mainly show that the two assessment methods lead to significantly different outcomes, in terms of ride comfort, under identical running conditions of the vehicle.

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.

Effect of unsupported sleepers on dynamic behavior of running vehicles and ride comfort index

2021 ◽  
pp. 095440622198937
Author(s):  
Mojtaba Azizi ◽  
Majid Shahravi ◽  
Jabbar-Ali Zakeri
Keyword(s):  
Numerical Model ◽  
Dynamic Behavior ◽  
Multibody Dynamics ◽  
Field Test ◽  
Ride Comfort ◽  
Vehicle Speed ◽  
Comfort Index ◽  
Railway Industry ◽  
Flexible Track ◽  
Train Speed

Nowadays, with various advancements in the railway industry and increasing speed of trains, the design of railway tracks and vehicles has become vitally important. One of the frequent problems of ballasted tracks is the existence of unsupported sleepers. This phenomenon occurs due to the lack of ballast underneath the sleepers. Here, a model is presented, in which a flexible track model in a multibody dynamics program is developed, in order to study the dynamic behavior of a vehicle. By utilizing the model, it is feasible to simulate unsupported sleepers on the flexible track including rail, sleeper, and ballast components. In order to verify the results of numerical model, a field test is performed. Findings indicate that, in the case of a single unsupported sleeper through the track, the ride comfort index increased by 100% after increasing the train speed from 30 to 110 km/h. Moreover, when it is needed to have ride comfort index improvement over the uncomfortable level, the vehicle speed should be less than 70 km/h and 50 km/h for tracks with one unsupported sleeper and two unsupported sleepers, respectively.

Dynamic Performance of HTS Maglev and Comparisons with Another Two Types of High-Speed Railway Vehicles

Cryogenics ◽  
2021 ◽  
pp. 103321
Author(s):  
Yuhang Yuan ◽  
Jipeng Li ◽  
Zigang Deng ◽  
Zhehao Liu ◽  
Dingding Wu ◽  
...  
Keyword(s):  
High Speed ◽  
Dynamic Performance ◽  
High Speed Railway ◽  
Railway Vehicles ◽  
Hts Maglev

scholarly journals Multi-Objective Lightweight Optimization of Parameterized Suspension Components Based on NSGA-II Algorithm Coupling with Surrogate Model

Machines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 107
Author(s):  
Rongchao Jiang ◽  
Zhenchao Jin ◽  
Dawei Liu ◽  
Dengfeng Wang
Keyword(s):  
Ride Comfort ◽  
Lightweight Design ◽  
Dynamic Performance ◽  
Vehicle Dynamic ◽  
Multi Objective Optimization ◽  
Original Design ◽  
Dynamic Simulations ◽  
Nsga Ii ◽  
Torsion Beam ◽  
Multi Objective

In order to reduce the negative effect of lightweighting of suspension components on vehicle dynamic performance, the control arm and torsion beam widely used in front and rear suspensions were taken as research objects for studying the lightweight design method of suspension components. Mesh morphing technology was employed to define design variables. Meanwhile, the rigid–flexible coupling vehicle model with flexible control arm and torsion beam was built for vehicle dynamic simulations. The total weight of control arm and torsion beam was taken as optimization objective, as well as ride comfort and handling stability performance indexes. In addition, the fatigue life, stiffness, and modal frequency of control arm and torsion beam were taken as the constraints. Then, Kriging model and NSGA-II were adopted to perform the multi-objective optimization of control arm and torsion beam for determining the lightweight scheme. By comparing the optimized and original design, it indicates that the weight of the optimized control arm and torsion beam are reduced 0.505 kg and 1.189 kg, respectively, while structural performance and vehicle performance satisfy the design requirement. The proposed multi-objective optimization method achieves a remarkable mass reduction, and proves to be feasible and effective for lightweight design of suspension components.

Performance analysis of MR damper based semi-active suspension system using optimally tuned controllers

2021 ◽  
pp. 095440702110044
Author(s):  
Gurubasavaraju Tharehalli mata ◽  
Vijay Mokenapalli ◽  
Hemanth Krishna
Keyword(s):  
Pid Controller ◽  
Ride Comfort ◽  
Sliding Mode ◽  
Dynamic Performance ◽  
Parametric Method ◽  
Mr Damper ◽  
Active Suspension ◽  
Suspension System ◽  
Sliding Mode Controller ◽  
Road Excitation

This study assesses the dynamic performance of the semi-active quarter car vehicle under random road conditions through a new approach. The monotube MR damper is modelled using non-parametric method based on the dynamic characteristics obtained from the experiments. This model is used as the variable damper in a semi-active suspension. In order to control the vibration caused under random road excitation, an optimal sliding mode controller (SMC) is utilised. Particle swarm optimisation (PSO) is coupled to identify the parameters of the SMC. Three optimal criteria are used for determining the best sliding mode controller parameters which are later used in estimating the ride comfort and road handling of a semi-active suspension system. A comparison between the SMC, Skyhook, Ground hook and PID controller suggests that the optimal parameters with SMC have better controllability than the PID controller. SMC has also provided better controllability than the PID controller at higher road roughness.

scholarly journals Improvement of the Lateral Ride Comfort on Railway Vehicles by Application of Pneumatic Actuators for Centering

2017 ◽  
Vol 58 (1) ◽  
pp. 14-20 ◽  
Author(s):  
Kotaro ISHIGURI ◽  
Akihito KAZATO ◽  
Kohei MIYAHARA ◽  
Masataka NIIYAMA ◽  
Katsumi SASAKI
Keyword(s):  
Ride Comfort ◽  
Pneumatic Actuators ◽  
Railway Vehicles

scholarly journals Thermal comfort index in lactating cows in an adapted free-stall facility

2020 ◽  
Vol 11 (4) ◽  
Author(s):  
João Marcos de Carvalho Vasconcelos ◽  
Sindynara Ferreira ◽  
Elisa De Souza Junqueira Rezende ◽  
José Luiz de Andrade Rezende Pereira
Keyword(s):  
Body Temperature ◽  
Relative Humidity ◽  
Thermal Comfort ◽  
Experimental Period ◽  
Temporal Variations ◽  
Holstein Cattle ◽  
Black And White ◽  
Comfort Index ◽  
Lactating Cows ◽  
Comfort Indices

This study was conducted to investigate the thermoregulation of Holstein cattle in an adapted free-stall facility at IFSULDEMINAS, Campus Inconfidentes, by measuring thermal comfort indices. The experimental period was from the end of December 2012 to the start of January 2013, in a total of 16 days. 12 multiparous, lactating, black-and-white Holstein cows were used in a free-stall system. Rectal temperature, respiratory frequency, ambient temperature and relative humidity were recorded at 3:00 a.m., 7:00 a.m., 11:00 a.m., 3:00 p.m., 7:00 p.m. and 11:00 p.m. The results demonstrate that despite the temporal variations that occurred throughout the evaluation days, the confined animals maintained their body temperature in balance.

Sign in / Sign up

Export Citation Format

Share Document