31 results on '"railway vehicle"'
Search Results
2. Basic study on vertical vibrations suppression in railway vehicle carbody by secondary suspension control using bogie vertical vibration velocity
- Author
-
Yoshiki SUGAHARA and Ayumi AMANO
- Subjects
railway vehicle ,active suspension ,vertical vibration ,ride comfort ,secondary suspension ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
This study investigates a new method for the effective application of active secondary suspension for reducing vertical vibration of the carbody to improve ride comfort of railway vehicles. So far, most previous control methods have contributed to reducing the vibration of the rigid body modes of the carbody at approximately 1 Hz or the first bending mode at approximately 10 Hz. However , in modern high-speed vehicles, higher frequency vibrations generally have a relatively greater influence on vertical ride comfort than vibrations of around 1–2 Hz. Focusing on this fact, the authors propose active secondary suspension with feedback control of the vertical vibration velocity of the bogie frame as a method for reducing carbody vibrations in a wide frequency band above 2 Hz to improve ride comfort. Numerical simulations were carried out to simulate the actual running of a Shinkansen using a vehicle model corresponding to a Shinkansen vehicle with 14 degrees of freedom, considering the vertical and longitudinal dynamics of the vehicle. The results show that this method is mainly effective in reducing vertical carbody vibration above 3 Hz and that the frequency band for vibration reduction can be extended to 1 Hz or lower by combining this method with feedback control of the vertical displacement of the bogie.
- Published
- 2024
- Full Text
- View/download PDF
3. The Effect of the Traction Rod on the Vertical Vibration Behavior of the Railway Vehicle Carbody
- Author
-
Mădălina Dumitriu and Ioana Izabela Apostol
- Subjects
railway vehicle ,traction rod ,vertical vibration ,numerical simulation ,ride comfort ,Mechanical engineering and machinery ,TJ1-1570 ,Machine design and drawing ,TJ227-240 ,Motor vehicles. Aeronautics. Astronautics ,TL1-4050 - Abstract
Although research has shown that through the additional rigidity introduced in the secondary suspension, traction rods can affect the vertical dynamic performance of railway vehicles, this topic has been less studied by researchers in the field. In this paper, the effect of a traction rod on the vertical vibration behavior of a carbody of a railway vehicle is analyzed, using the results obtained through numerical simulations. Numerical simulation applications are developed based on a vehicle model, where the vehicle carbody is modeled using a free-free equivalent beam Euler–Bernoulli, and the bogie chassis and wheelsets are represented by rigid bodies linked together by Kelvin-Voigt systems that model the secondary suspension and the primary suspension. The novelty element of this paper is found in the model of the traction rod. This includes traction rod damping, which has been neglected in previous research. The stiffness and damping of the traction rod are represented by a longitudinal Kelvin–Voigt system integrated into a secondary suspension model. The effect of the traction rod on the vertical vibration behavior of the vehicle carbody is analyzed based on the power spectral density of the acceleration, the root mean square of acceleration, and the ride comfort index, for three cases for analysis: a ‘without traction rod’ case, a ‘with traction rod—with damping’ case, and a ‘with traction rod—without damping’ case. The conclusions of the paper highlight the influence of the stiffness and damping of the traction rod on the vibration level of the carbody, especially in its middle. Depending on the stiffness of the traction rod, significant increases in the ride comfort index are obtained, which at high velocities can exceed 300%. Damping of the traction rod reduces the ride comfort index by up to 10%.
- Published
- 2023
- Full Text
- View/download PDF
4. The Effect of the Traction Rod on the Vertical Vibration Behavior of the Railway Vehicle Carbody.
- Author
-
Dumitriu, Mădălina and Apostol, Ioana Izabela
- Subjects
RAILROAD trains ,BOGIES (Vehicles) ,ROOT-mean-squares ,RIGID bodies ,RESEARCH personnel - Abstract
Although research has shown that through the additional rigidity introduced in the secondary suspension, traction rods can affect the vertical dynamic performance of railway vehicles, this topic has been less studied by researchers in the field. In this paper, the effect of a traction rod on the vertical vibration behavior of a carbody of a railway vehicle is analyzed, using the results obtained through numerical simulations. Numerical simulation applications are developed based on a vehicle model, where the vehicle carbody is modeled using a free-free equivalent beam Euler–Bernoulli, and the bogie chassis and wheelsets are represented by rigid bodies linked together by Kelvin-Voigt systems that model the secondary suspension and the primary suspension. The novelty element of this paper is found in the model of the traction rod. This includes traction rod damping, which has been neglected in previous research. The stiffness and damping of the traction rod are represented by a longitudinal Kelvin–Voigt system integrated into a secondary suspension model. The effect of the traction rod on the vertical vibration behavior of the vehicle carbody is analyzed based on the power spectral density of the acceleration, the root mean square of acceleration, and the ride comfort index, for three cases for analysis: a 'without traction rod' case, a 'with traction rod—with damping' case, and a 'with traction rod—without damping' case. The conclusions of the paper highlight the influence of the stiffness and damping of the traction rod on the vibration level of the carbody, especially in its middle. Depending on the stiffness of the traction rod, significant increases in the ride comfort index are obtained, which at high velocities can exceed 300%. Damping of the traction rod reduces the ride comfort index by up to 10%. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
5. Design of a lateral active suspension controller for railway vehicles: a focus on ride comfort and perturbations.
- Author
-
Park, Jungwan and Yang, Hyunseok
- Subjects
- *
RAILROAD trains , *MOMENTS of inertia , *BOGIES (Vehicles) , *WHEELS , *DYNAMIC models , *ROBUST control - Abstract
This paper presents a study on the dynamic model and robust controller design for enhancing ride comfort in railway vehicles. An analytical model is introduced, encompassing the lateral, roll, and yaw motions of wheelsets, bogies, and the car body, while incorporating an efficient method for computing wheel-rail interactions. Rail irregularities and their impact on vibration excitation are also examined. A robust controller design methodology is proposed to address uncertainty and ride comfort quality, considering the significant variations in mass and moment of inertia experienced by railway vehicles. Through simulations, the designed controller consistently demonstrates an approximate 2 dB improvement in ride comfort across different levels of uncertainty. Future research directions include developing controller designs considering actuator response characteristics and identifying additional conditions for practical implementation. This study contributes to understanding railway vehicle dynamics and lays the foundation for effective control strategies to enhance ride comfort while accommodating uncertain operating conditions. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
6. Scale Models to Verify the Effectiveness of the Methods to Reducing the Vertical Bending Vibration of the Railway Vehicles Carbody: Applications and Design Elements.
- Author
-
Dumitriu, Mădălina, Mazilu, Traian, and Apostol, Ioana Izabela
- Subjects
RAILROAD trains ,MODELS & modelmaking ,HUMAN body ,VEHICLE models ,DESIGN - Abstract
The purpose of this paper is to present applications and design elements of scale models of the carbody of railway vehicles integrated in experimental laboratory systems to verify the effectiveness of the methods to reduce vertical bending vibration of the carbody. In the first part of the paper, some applications of such experimental systems are presented, which include different scale models of the railway vehicle carbody. In the second part of the paper, the structure and dimensioning elements of a new demonstrative experimental system, specially designed by the authors of the present paper for testing the functionality of an original method of reducing the vertical bending vibrations of the carbody of railway vehicles, are presented. This method is based on an innovative approach that involves the use of a passive system consisting of two bars rigidly mounted on the longitudinal beams of the carbody underframe, having the role of opposing the bending of the carbody. The main element of the demonstrative experimental system is the scale model of the vehicle carbody, reduced to a beam, on which the two bars, called anti-bending bars, are mounted. For the dimensioning of the experimental model of the carbody and the anti-bending bars, original methodologies are developed in which several conditions are involved. In the case of the dimensioning of the experimental model of the carbody, the conditions refer to the convenient adoption of the scaling factor of the dimensions of the real carbody from the perspective of the practical realization of the experimental model of the carbody, ensuring the buckling stability of the demonstrative experimental system, achieving natural frequency of the vertical bending of the real carbody and avoiding the interference of the bounce vibration with the vertical bending vibration of the demonstrative experimental model of the carbody. The dimensions of the anti-bending bars are established from the condition that the vertical bending frequency of the experimental model of the carbody is outside the range of sensitivity of the human body to vertical vibration. Additionally, the natural frequency of the vertical bending vibration of the anti-bending bars must be chosen to avoid interference with the vertical bending vibration of the experimental model of the carbody. The effectiveness of the anti-bending bars in reducing the vertical bending vibration of the experimental model of the carbody is investigated with the help of numerical simulation results developed based on an original theoretical model of the experimental model of the carbody with anti-bending bars. [ABSTRACT FROM AUTHOR]
- Published
- 2023
- Full Text
- View/download PDF
7. Effect of the asymmetry of suspension damping on the ride comfort of railway vehicles.
- Author
-
Dumitriu, Mădălina
- Subjects
- *
RAILROAD trains , *MOTOR vehicle springs & suspension , *HUMAN body , *BOGIES (Vehicles) , *COMPUTER simulation - Abstract
In terms of reliability, the damper represents the critical element of the suspension in the rail vehicle. A damper failure brings about a reduction in the damping of the suspension it belongs to, thus leading to the asymmetry of the suspension damping in the vehicle. The paper presents an analysis of the effect that the asymmetry of the secondary suspension damping has on the vertical vibration behaviour in the vehicle carbody and on the ride comfort, while using to that purpose the results derived from numerical simulations. The characteristics of the vibration behaviour for the resonance frequencies of the carbody dominant vertical modes are pointed out via the power spectral density of the carbody acceleration, which is weighted by the function of the sensitivity of the human body to the vertical vibrations. The ride comfort is assessed based on the ride index comfort calculated in three carbody reference points – at the centre and above the two bogies. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
8. Scale Models to Verify the Effectiveness of the Methods to Reducing the Vertical Bending Vibration of the Railway Vehicles Carbody: Applications and Design Elements
- Author
-
Mădălina Dumitriu, Traian Mazilu, and Ioana Izabela Apostol
- Subjects
railway vehicle ,bending vibration ,ride comfort ,demonstrative experimental system ,scale model ,anti-bending bars ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The purpose of this paper is to present applications and design elements of scale models of the carbody of railway vehicles integrated in experimental laboratory systems to verify the effectiveness of the methods to reduce vertical bending vibration of the carbody. In the first part of the paper, some applications of such experimental systems are presented, which include different scale models of the railway vehicle carbody. In the second part of the paper, the structure and dimensioning elements of a new demonstrative experimental system, specially designed by the authors of the present paper for testing the functionality of an original method of reducing the vertical bending vibrations of the carbody of railway vehicles, are presented. This method is based on an innovative approach that involves the use of a passive system consisting of two bars rigidly mounted on the longitudinal beams of the carbody underframe, having the role of opposing the bending of the carbody. The main element of the demonstrative experimental system is the scale model of the vehicle carbody, reduced to a beam, on which the two bars, called anti-bending bars, are mounted. For the dimensioning of the experimental model of the carbody and the anti-bending bars, original methodologies are developed in which several conditions are involved. In the case of the dimensioning of the experimental model of the carbody, the conditions refer to the convenient adoption of the scaling factor of the dimensions of the real carbody from the perspective of the practical realization of the experimental model of the carbody, ensuring the buckling stability of the demonstrative experimental system, achieving natural frequency of the vertical bending of the real carbody and avoiding the interference of the bounce vibration with the vertical bending vibration of the demonstrative experimental model of the carbody. The dimensions of the anti-bending bars are established from the condition that the vertical bending frequency of the experimental model of the carbody is outside the range of sensitivity of the human body to vertical vibration. Additionally, the natural frequency of the vertical bending vibration of the anti-bending bars must be chosen to avoid interference with the vertical bending vibration of the experimental model of the carbody. The effectiveness of the anti-bending bars in reducing the vertical bending vibration of the experimental model of the carbody is investigated with the help of numerical simulation results developed based on an original theoretical model of the experimental model of the carbody with anti-bending bars.
- Published
- 2023
- Full Text
- View/download PDF
9. Investigation of low damped carbody oscillation for Korean high-speed EMU experimental train.
- Author
-
Park, Joonhyuk
- Abstract
This study describes the low damped carbody oscillations of the HEMU-430X, a high-speed electric-multiple-unit experimental train of Korea. The HEMU-430X had already undergone a kind of hunting problem in the test period, but it was effectively suppressed through several measures and the test was finished successfully. However, recently, the HEMU-430X again experienced the similar but slightly different problem after its wheel profile was changed to XP55, which is widely used in high-speed trains in Korea. In this paper, the eigenbehavior and system damping ratio are analyzed using a linearized vehicle model to more systematically investigate the cause of the carbody oscillation of the HEMU-430X. The results show that the bogie lateral movement coupled with carbody upper sway has the least damping ratio in the case of the HEMU-430X and the magnitude of yaw directional constraints of the bogie plays an important role in causing the carbody oscillation. Parametric studies for suspension, equivalent conicity and creep coefficients are carried out. A solution is suggested and it is validated using field tests. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
10. Reduction of vertical vibration of railway vehicle with high-damping elastic support of underfloor equipment
- Author
-
Ken-ichiro AIDA, Yuki AKIYAMA, Tadao TAKIGAMI, and Takahiro TOMIOKA
- Subjects
railway ,railway vehicle ,vertical vibration ,dynamic vibration absorber ,vibration reduction ,ride comfort ,vibration isolation ,Mechanical engineering and machinery ,TJ1-1570 ,Engineering machinery, tools, and implements ,TA213-215 - Abstract
This paper presents a method for reducing vertical vibrations in a railway vehicle carbody by supporting underfloor equipment using high-damping elastic mounts. This is a kind of dynamic vibration absorber utilizing underfloor equipment as a mass element which has been introduced based on the inspiration of the damping effect of passengers. Numerical studies were firstly carried out to check the feasibility of the idea using simple two degree of freedom model representing carbody and underfloor equipment. Then a prototype of the elastic supporting member was built as a simple rubber mount and two type of excitation tests were conducted using a Shinkansen type test vehicle. The authors conducted excitation tests in the rolling stock testing plant to examine the carbody vibration reduction effect due to track irregularity. As a result, two dominant peaks in the acceleration power spectrum densities of floor corresponding to different elastic vibration modes were reduced simultaneously when the proposed method was applied. The vibration reduction effect became large as the elastically supported mass of underfloor increased. Then, to examine the vibration isolation performance of the developed rubber mount, excitation tests were conducted by a vibration exciter installed on the underfloor equipment. From the random wave excitation, the authors confirmed that the vertical vibration of carbody floor is reduced over a wide frequency band.
- Published
- 2021
- Full Text
- View/download PDF
11. Study on the Evaluation Methods of the Vertical Ride Comfort of Railway Vehicle—Mean Comfort Method and Sperling's Method.
- Author
-
Dumitriu, Mădălina, Stănică, Dragoș Ionuț, Park, Junhong, and Vasques, César M. A.
- Subjects
RAILROAD trains ,EVALUATION methodology ,COMPUTER simulation ,VEHICLE models - Abstract
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 N
MVZ 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. [ABSTRACT FROM AUTHOR]- Published
- 2021
- Full Text
- View/download PDF
12. Numerical analysis on the influence of suspended equipment on the ride comfort in railway vehicles
- Author
-
Mădălina Dumitriu
- Subjects
railway vehicle ,flexible carbody ,suspended equipment ,bending vibration ,ride comfort ,Mechanics of engineering. Applied mechanics ,TA349-359 - Abstract
To study the impact of suspended equipment on the ride comfort in a railway vehicle, a rigid flexible general model of such a vehicle is required. The numerical simulations is based on two different models, derived from the general model of the vehicle, namely a reference model of a vehicle with no equipment, and another model with six suspended elements of equipment mounted in various positions along the carbody. The objective of this paper arises from the observation that the literature does not contain any study that highlights the change in the ride comfort resulting exclusively due to the influence of equipment. The influence of the suspended equipment on the ride comfort is determined by comparing the ride comfort indices calculated in the carbody reference points, at the centre and above the two bogies, for a model with six elements of equipment and a model of the vehicle with no equipment.
- Published
- 2018
- Full Text
- View/download PDF
13. Introduction
- Author
-
Knothe, Klaus, Stichel, Sebastian, Knothe, Klaus, and Stichel, Sebastian
- Published
- 2017
- Full Text
- View/download PDF
14. Effect of the Anti-Yaw Damper on Carbody Vertical Vibration and Ride Comfort of Railway Vehicle.
- Author
-
Dumitriu, Mădălina and Stănică, Dragoș Ionuț
- Subjects
RAILROAD trains ,MECHANICAL models ,VEHICLE models ,COMPUTER simulation - Abstract
The theoretical research on means to reduce the vertical vibrations and improve the ride comfort of the railway vehicle relies on a mechanical model obtained from the simplified representation of the vehicle, while considering the important factors and elements affecting the vibration behaviour of the carbody. One of these elements is the anti-yaw damper, mounted longitudinally, between the bogie and the vehicle carbody. The anti-yaw damper reduces the lateral vibrations and inhibits the yaw motion of the vehicle, a reason for which this element is not usually introduced in the vehicle model when studying the vertical vibrations. Nevertheless, due to the position of the clamping points of the anti-yaw damper onto the carbody and the bogie, the damping force is generated not only in the yawing direction but also in the vertical and longitudinal directions. These forces act upon the vehicle carbody, impacting its vertical vibration behaviour. The paper analyzes the effect of the anti-winding damper on the vertical vibrations of the railway vehicle carbody and the ride comfort, based on the results derived from the numerical simulations. They highlight the influence of the damping, stiffness and the damper mounting angle on the power spectral density of the carbody vertical acceleration and the ride comfort index. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
15. Evaluation of power regeneration in primary suspension for a railway vehicle.
- Author
-
Wang, Ruichen and Wang, Zhiwei
- Abstract
To improve the fuel economy of rail vehicles, this study presents the feasibility of using power regenerating dampers (PRDs) in the primary suspension systems of railway vehicles and evaluates the potential and recoverable power that can be obtained. PRDs are configured as hydraulic electromagnetic-based railway primary vertical dampers and evaluated in parallel and series modes (with and without a viscous damper). Hydraulic configuration converts the linear behavior of the track into a unidirectional rotation of the generator, and the electromagnetic configuration provides a controllable damping force to the primary suspension system. In several case studies, generic railway vehicle primary suspension systems that are configured to include a PRD in the two configuration modes are modeled using computer simulations. The simulations are performed on measured tracks with typical irregularities for a generic UK passenger route. The performance of the modified vehicle is evaluated with respect to key performance indicators, including regenerated power, ride comfort, and running safety. Results indicate that PRDs can simultaneously replace conventional primary vertical dampers, regenerate power, and exhibit desirable dynamic performance. A peak power efficiency of 79.87% is theoretically obtained in series mode on a top-quality German Intercity Express track (Track 270) at a vehicle speed of 160 mile/h (∼257 km/h). [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
16. Dynamic optimization design of the suspension parameters of car body-mounted equipment via analytical target cascading.
- Author
-
Chen, Jie, Wu, Yangjun, Zhang, Limin, He, Xiaolong, and Dong, Shijie
- Subjects
- *
RAILROAD trains , *HIGH speed trains , *RUNNING speed , *VEHICLE models , *COMPUTER simulation - Abstract
Under dynamic conditions, the dynamic force between the suspended equipment and the car body is substantially increased. This increase not only affects the ride comfort but also substantially raises the likelihood of fatigue damage to the suspended equipment. A multiobjective analytical target cascading (ATC) optimization is proposed to improve the ride comfort of high-speed trains and reduce the vibration of the suspended equipment. A mathematical simulation model of the vehicle equipment system is established, and the acceleration frequency-response function expression of the car body and the suspension system is obtained. The comfort index of the car body and the acceleration root mean square (RMS) of the suspended equipment are calculated by combining the German vertical irregular track spectrum and the comfort filter function. Meanwhile, the ATC method is used to optimize the car body comfort index and the acceleration RMS of the underframe suspended equipment. Then, the availability of the optimization method is evaluated via numerical simulation. Compared with the original suspension scheme of the underframe equipment, when the running speed of the vehicle is 300 km/h, the RMS value of the vibrational acceleration of the underframe equipment after optimization decreases by 19.9 %, and the ride comfort indexes at the car body center and above the front and rear bogies are improved by 6.4 %, 0.1 %, and 1.1 %, respectively. Simulation results demonstrate that ATC optimization can improve the railway vehicle ride comfort and reduce the vibration of the suspended equipment. This paper provides a new approach to the suspension parameter design of equipment. [ABSTRACT FROM AUTHOR]
- Published
- 2020
- Full Text
- View/download PDF
17. Study on the Evaluation Methods of the Vertical Ride Comfort of Railway Vehicle—Mean Comfort Method and Sperling’s Method
- Author
-
Mădălina Dumitriu and Dragoș Ionuț Stănică
- Subjects
railway vehicle ,ride comfort ,mean comfort method ,Sperling’s method ,frequency weighting ,numerical simulation ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
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.
- Published
- 2021
- Full Text
- View/download PDF
18. NUMERICAL ANALYSIS ON THE INFLUENCE OF SUSPENDED EQUIPMENT ON THE RIDE COMFORT IN RAILWAY VEHICLES.
- Author
-
DUMITRIU, MáDáLINA
- Subjects
- *
NUMERICAL analysis , *ENERGY consumption , *ELECTRIC multiple units , *EIGENFREQUENCIES , *MOTOR vehicle dynamics - Abstract
To study the impact of suspended equipment on the ride comfort in a railway vehicle, a rigid flexible general model of such a vehicle is required. The numerical simulations is based on two different models, derived from the general model of the vehicle, namely a reference model of a vehicle with no equipment, and another model with six suspended elements of equipment mounted in various positions along the carbody. The objective of this paper arises from the observation that the literature does not contain any study that highlights the change in the ride comfort resulting exclusively due to the influence of equipment. The influence of the suspended equipment on the ride comfort is determined by comparing the ride comfort indices calculated in the carbody reference points, at the centre and above the two bogies, for a model with six elements of equipment and a model of the vehicle with no equipment. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
19. Effect of the Anti-Yaw Damper on Carbody Vertical Vibration and Ride Comfort of Railway Vehicle
- Author
-
Mădălina Dumitriu and Dragoș Ionuț Stănică
- Subjects
railway vehicle ,anti-yaw damper ,vertical vibration ,ride comfort ,Technology ,Engineering (General). Civil engineering (General) ,TA1-2040 ,Biology (General) ,QH301-705.5 ,Physics ,QC1-999 ,Chemistry ,QD1-999 - Abstract
The theoretical research on means to reduce the vertical vibrations and improve the ride comfort of the railway vehicle relies on a mechanical model obtained from the simplified representation of the vehicle, while considering the important factors and elements affecting the vibration behaviour of the carbody. One of these elements is the anti-yaw damper, mounted longitudinally, between the bogie and the vehicle carbody. The anti-yaw damper reduces the lateral vibrations and inhibits the yaw motion of the vehicle, a reason for which this element is not usually introduced in the vehicle model when studying the vertical vibrations. Nevertheless, due to the position of the clamping points of the anti-yaw damper onto the carbody and the bogie, the damping force is generated not only in the yawing direction but also in the vertical and longitudinal directions. These forces act upon the vehicle carbody, impacting its vertical vibration behaviour. The paper analyzes the effect of the anti-winding damper on the vertical vibrations of the railway vehicle carbody and the ride comfort, based on the results derived from the numerical simulations. They highlight the influence of the damping, stiffness and the damper mounting angle on the power spectral density of the carbody vertical acceleration and the ride comfort index.
- Published
- 2020
- Full Text
- View/download PDF
20. Numerical and experimental studies on the car body flexible vibration reduction due to the effect of car body-mounted equipment.
- Author
-
Caihong Huang, Jing Zeng, Guangbing Luo, and Huailong Shi
- Abstract
To study the effect of car body-mounted equipment on the car body flexible vibration, a vertical rigid-flexible coupling model of a high-speed vehicle is established, which includes a flexible car body, rigid bodies for two bogie frames, four wheelsets, and the car body-mounted equipment. The car body is approximated by an elastic beam, with dimensions selected to give similar mass and vertical bending frequency to an existing car body. Model validation is then carried out by comparing results from numerical simulation and on-track test. Using frequency response analysis and ride comfort analysis, parametric studies are undertaken in order to investigate the respective effect of equipment mounting systems on the car body flexible vibration and ride comfort perceived by the passenger. It is found that the equipment behaves as a dynamic vibration absorber on account of its elastic connections to the car body. The stiffness, damping, mass, and installing position of the equipment have a significant influence on the car body flexible vibration. The optimal parameters of the dynamic vibration absorber are given, which can contribute much to the vibration absorption of the car body flexible vibration. Finally, extensive tests on a high-speed test vehicle are conducted to represent a part of results obtained in the numerical study, including modal tests on the car body, component tests on rubber springs used in the equipment mounting systems, and roller rig tests on the vibration absorption performance of the equipment. It is shown that the car body flexible vibration can be effectively suppressed by reasonably suspending the car body-mounted equipment. [ABSTRACT FROM AUTHOR]
- Published
- 2018
- Full Text
- View/download PDF
21. A new passive approach to reducing the carbody vertical bending vibration of railway vehicles.
- Author
-
Dumitriu, Mădălina
- Subjects
- *
AUTOMATIC train control , *TRAFFIC safety , *VIBRATION (Mechanics) , *AUTOMOBILE engine vibration , *SYSTEM dynamics , *AUTOMOTIVE engineering - Abstract
This paper brings to view a new passive approach regarding the reduction of the flexible carbody vertical bending vibration of railway vehicles via two anti-bending bars fixed onto the longitudinal beams of a carbody underframe. The anti-bending bars operate as elastic elements limiting the rotation of the carbody cross-sections and thus increasing the bending carbody frequency. The anti-bending bars are dimensioned so that the frequency of the first bending mode of the carbody to be convenient in terms of ride comfort. The effectiveness in the use of the anti-bending bars is proven by the lowering of the vibration level and improvement of the vehicle ride comfort. [ABSTRACT FROM PUBLISHER]
- Published
- 2017
- Full Text
- View/download PDF
22. Optimal Design of the Layout of Railway Passenger Vehicles
- Author
-
Mastinu, Giampiero, Gobbi, Massimiliano, Miano, Carlo, Mastinu, Giampiero, Gobbi, Massimiliano, and Miano, Carlo
- Published
- 2006
- Full Text
- View/download PDF
23. Optimization of damping effect for the air spring by the frequency dependent orifice
- Author
-
Yuichiro TAKINO, Hiroshi SHINMURA, Takeyosi MIHARA, Nobuyuki OKADA, Naohide KAMIKAWA, and Koichiro NANBA
- Subjects
railway vehicle ,air spring ,frequency-dependent orifice ,ride comfort ,vibration control ,frequency characteristics ,Mechanical engineering and machinery ,TJ1-1570 - Abstract
This study proposes a newly developed structure for a frequency-dependent orifice for an air spring of a passenger train vehicle. This frequency-dependent orifice reduced both the rolling motion and the vertical vibration at high frequency. This paper also presents the numerical simulation results. Optimal settings of the springs and dampers of the bogie are essential for reducing the uncomfortable carbody motion while the train is running. The air springs provide insulation and damping through air compressibility in the bellows and pressure loss of the airflow passing through an orifice installed between the air spring and the auxiliary reservoir. The frequency characteristics of a standard air spring show a peak at a frequency of ~1 Hz of the rolling motion of the carbody. A smaller orifice seems to be one of the solutions to change this characteristic. However, this method worsens the damping property at high frequency. To solve this problem, a frequency-dependent orifice with active vibration control technology has been proposed. This orifice improves the vertical vibration at low frequencies and the rolling motion of the carbody; however, it does not improve the properties at high frequencies. The results of our previous research left issues such as the need to improve the high-frequency response in a future study. The results of this study show that our newly developed frequency-dependent orifice effectively reduces the vertical vibration at high frequency with no external power supply. We are planning further simulations including realistic disturbance and a running test using a prototype of the frequency-dependent orifice.
- Published
- 2017
- Full Text
- View/download PDF
24. Simulation for whole-body vibration to assess ride comfort of a low–medium speed railway vehicle.
- Author
-
Kumar, Vivek, Rastogi, Vikas, and Pathak, P. M.
- Subjects
- *
HUMAN comfort , *RAILROADS , *VIBRATION (Mechanics) , *SIMULATION methods & models , *MATHEMATICAL models - Abstract
Vibration in trains constitutes one aspect of the physical environment that can cause discomfort to passengers. In order to assess the vibration, a variety of techniques have been developed and used. The general approach is to acquire acceleration at the passenger–train interface, and to then process these acceleration signals in order to calculate human comfort. However, the comfort index so calculated is independent of the seat characteristics and human parameters. Thus, a human biodynamic model with dynamic seat characteristics is necessary in order to perform true comfort analysis. The biodynamics of human subjects has been a topic of interest over the years, and a number of mathematical models have been established. However, there are only a few studies incorporating biodynamic models in railway applications. So, the present work proposes to evaluate Sperling’s Ride Index for a low–medium speed railway vehicle and further to calculate root mean square acceleration of different body parts, as per the International Organization for Standardization (ISO) 2631 guidelines, through bond graph technique. Car body flexibility is also incorporated using modal expansion of a free–free beam. Physiological effects of the vibrations on the human body were analyzed using the criteria specified in ISO 2631. [ABSTRACT FROM AUTHOR]
- Published
- 2017
- Full Text
- View/download PDF
25. Analysis of the dynamic response in the railway vehicles to the track vertical irregularities. Part II: The numerical analysis.
- Author
-
Dumitriu, M.
- Subjects
- *
RAILROADS , *TRANSPORTATION , *NUMERICAL analysis , *BOGIES (Vehicles) , *MOTOR vehicles -- Chassis - Abstract
The paper examines the dynamic response of a two-bogie vehicle to the symmetrical and antisymmetrical excitations, due to bounce and pitch of the axles' planes, derived from the track vertical irregularities. Part I introduced the theoretical model and the response functions of the vehicle, as well as the theoretical elements required for the analysis of the dynamic response of the vehicle to the track stochastic irregularities. Part II comprises the results of the numerical analysis of the vehicle dynamic response in three reference points of the carbody, based on which a series of properties of the vertical vibrations behaviour of the railway vehicle is pointed out at. The excitation modes that trigger the carbody response in its reference points are identified. Hence, the influence of the geometrical filtering effect of the excitation modes upon the ride quality and ride comfort is established. [ABSTRACT FROM AUTHOR]
- Published
- 2015
26. EVALUATION OF THE RIDE QUALITY AND RIDE COMFORT IN RAILWAY VEHICLES BASED ON THE INDEX Wz.
- Author
-
DUMITRIU, Mădălina and GHEȚI, Marius Alin
- Subjects
- *
COMPUTER simulation , *TRANSPORTATION - Abstract
This paper focuses on the evaluation of the ride quality and comfort during the vertical vibrations in the railway vehicles generated by the track irregularities, where this evaluation applies the ride index Wz method. The ride index Wz is calculated via certain applications of numerical simulation, based on which the impact of the velocity and of the suspension features upon the ride quality and ride comfort is analyzed. The derived results emphasize a series of attributes of the dynamic behaviour of the vehicle, as well as the possibilities of increasing the ride quality and comfort by means of an appropriate selection of the damping of the secondary suspension. [ABSTRACT FROM AUTHOR]
- Published
- 2015
27. Study on the Evaluation Methods of the Vertical Ride Comfort of Railway Vehicle—Mean Comfort Method and Sperling’s Method
- Author
-
Dragoș Ionuț Stănică and Mădălina Dumitriu
- Subjects
Technology ,QH301-705.5 ,Computer science ,QC1-999 ,frequency weighting ,Suspension (motorcycle) ,Frequency weighting ,Evaluation methods ,General Materials Science ,Biology (General) ,QD1-999 ,Instrumentation ,ride comfort ,Sperling’s method ,Fluid Flow and Transfer Processes ,railway vehicle ,Comfort index ,Computer simulation ,business.industry ,Physics ,Process Chemistry and Technology ,General Engineering ,mean comfort method ,Structural engineering ,Engineering (General). Civil engineering (General) ,Computer Science Applications ,Vibration ,Chemistry ,numerical simulation ,Assessment methods ,TA1-2040 ,business - Abstract
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.
- Published
- 2021
28. Optimization of damping effect for the air spring by the frequency dependent orifice
- Author
-
Hiroshi Shinmura, Naohide Kamikawa, Koichiro Nanba, Takeyosi Mihara, Nobuyuki Okada, and Yuichiro Takino
- Subjects
Engineering ,railway vehicle ,business.industry ,Air spring ,vibration control ,frequency characteristics ,air spring ,Mechanical engineering ,020302 automobile design & engineering ,frequency-dependent orifice ,02 engineering and technology ,020303 mechanical engineering & transports ,0203 mechanical engineering ,Control theory ,TJ1-1570 ,Mechanical engineering and machinery ,business ,Body orifice ,ride comfort - Abstract
This study proposes a newly developed structure for a frequency-dependent orifice for an air spring of a passenger train vehicle. This frequency-dependent orifice reduced both the rolling motion and the vertical vibration at high frequency. This paper also presents the numerical simulation results. Optimal settings of the springs and dampers of the bogie are essential for reducing the uncomfortable carbody motion while the train is running. The air springs provide insulation and damping through air compressibility in the bellows and pressure loss of the airflow passing through an orifice installed between the air spring and the auxiliary reservoir. The frequency characteristics of a standard air spring show a peak at a frequency of ~1 Hz of the rolling motion of the carbody. A smaller orifice seems to be one of the solutions to change this characteristic. However, this method worsens the damping property at high frequency. To solve this problem, a frequency-dependent orifice with active vibration control technology has been proposed. This orifice improves the vertical vibration at low frequencies and the rolling motion of the carbody; however, it does not improve the properties at high frequencies. The results of our previous research left issues such as the need to improve the high-frequency response in a future study. The results of this study show that our newly developed frequency-dependent orifice effectively reduces the vertical vibration at high frequency with no external power supply. We are planning further simulations including realistic disturbance and a running test using a prototype of the frequency-dependent orifice.
- Published
- 2017
29. Development and application of new evaluation system for ride comfort and vibration on railway vehicles.
- Author
-
Yoo, Wan-Suk, Lee, Chang-Hwan, Jeong, Weui-Bong, and Kim, Sang-Hyun
- Abstract
Vibrations related to ride comfort should be considered at the beginning of design stage. In general, ride comfort of human is mainly affected by vibration transmitted from the floor and seat. Also, vibration level is very important regarding with running safety on freight wagon. To ensure ride comfort for passenger coach and vibration level for freight wagon, tests had been repeated by different test procedures with several equipments. With different measuring and evaluations for these results, it took much time to evaluate test results. In this paper, a new evaluation procedure was developed combining several software for ride comfort and vibration level test on railway vehicles. In addition, this developed system is capable of ride comfort test and vibration test by a single integrated system that is capable of immediate reporting the test result. With this developed system, the comfort in a passenger coach and the vibration in a freight car were evaluated. And the simulation results from the proposed system are verified by a field test. [ABSTRACT FROM AUTHOR]
- Published
- 2005
- Full Text
- View/download PDF
30. Effect of the Anti-Yaw Damper on Carbody Vertical Vibration and Ride Comfort of Railway Vehicle
- Author
-
Dragoș Ionuț Stănică and Mădălina Dumitriu
- Subjects
Computer science ,Vertical vibration ,Theoretical research ,02 engineering and technology ,lcsh:Technology ,01 natural sciences ,Bogie ,Damper ,lcsh:Chemistry ,0203 mechanical engineering ,anti-yaw damper ,0103 physical sciences ,medicine ,General Materials Science ,lcsh:QH301-705.5 ,010301 acoustics ,Instrumentation ,ride comfort ,Fluid Flow and Transfer Processes ,railway vehicle ,lcsh:T ,business.industry ,Process Chemistry and Technology ,General Engineering ,vertical vibration ,Stiffness ,Structural engineering ,lcsh:QC1-999 ,Clamping ,Computer Science Applications ,Vibration ,020303 mechanical engineering & transports ,lcsh:Biology (General) ,lcsh:QD1-999 ,lcsh:TA1-2040 ,Yaw damper ,medicine.symptom ,lcsh:Engineering (General). Civil engineering (General) ,business ,lcsh:Physics - Abstract
The theoretical research on means to reduce the vertical vibrations and improve the ride comfort of the railway vehicle relies on a mechanical model obtained from the simplified representation of the vehicle, while considering the important factors and elements affecting the vibration behaviour of the carbody. One of these elements is the anti-yaw damper, mounted longitudinally, between the bogie and the vehicle carbody. The anti-yaw damper reduces the lateral vibrations and inhibits the yaw motion of the vehicle, a reason for which this element is not usually introduced in the vehicle model when studying the vertical vibrations. Nevertheless, due to the position of the clamping points of the anti-yaw damper onto the carbody and the bogie, the damping force is generated not only in the yawing direction but also in the vertical and longitudinal directions. These forces act upon the vehicle carbody, impacting its vertical vibration behaviour. The paper analyzes the effect of the anti-winding damper on the vertical vibrations of the railway vehicle carbody and the ride comfort, based on the results derived from the numerical simulations. They highlight the influence of the damping, stiffness and the damper mounting angle on the power spectral density of the carbody vertical acceleration and the ride comfort index.
- Published
- 2020
31. Investigation on the Bogie Pseudo-Hunting Motion of a Reduced-Scale Model Railway Vehicle Running on Double-Curved Rails
- Author
-
Barenten Suciu and Kinoshita, Ryoichi
- Subjects
railway vehicle ,yaw damper ,Double-curved rail ,octave analysis ,lateral vibration ,ride comfort - Abstract
In this paper, an experimental and theoretical study on the bogie pseudo-hunting motion of a reduced-scale model railway vehicle, running on double-curved rails, is presented. Since the actual bogie hunting motion, occurring for real railway vehicles running on straight rails at high travelling speeds, cannot be obtained in laboratory conditions, due to the speed and wavelength limitations, a pseudo- hunting motion was induced by employing double-curved rails. Firstly, the test rig and the experimental procedure are described. Then, a geometrical model of the double-curved rails is presented. Based on such model, the variation of the carriage rotation angle relative to the bogies and the working conditions of the yaw damper are clarified. Vibration spectra recorded during vehicle travelling, on straight and double-curved rails, are presented and interpreted based on a simple vibration model of the railway vehicle. Ride comfort of the vehicle is evaluated according to the ISO 2631 standard, and also by using some particular frequency weightings, which account for the discomfort perceived during the reading and writing activities. Results obtained in this work are useful for the adequate design of the yaw dampers, which are used to attenuate the lateral vibration of the train car bodies., {"references":["ISO 2631 Standard, Mechanical Vibration and Shock – Evaluation of Human Exposure to Whole-Body Vibration, 1997, pp. 1–27.","M. J. Griffin, Handbook of Human Vibration. London: Academic Press, 2003, 2nd ed., ch. 2–12, pp. 27–530.","O. Thuong, and M. J. Griffin, \"The Vibration Discomfort of Standing Persons: 0.5 to 16 Hz Fore – and – Aft, Lateral, and Vertical Vibration,\" Journal of Sound and Vibration, 330(4), pp. 816–826, 2011.","ENV 12299, Railway Applications – Ride Comfort for Passengers, 2010.","G. Gallais, H. Ohno, and C. Talotte, \"Frequency Weightings for the Evaluation of Discomfort of Standing Passengers on Trains,\" Proc. of 9th World Congress on Railway Research, pp. 1–12, 2011.","S. Komamura, R. Watanabe, K. Mizumukai, T. Mizobuchi, Y. Morita, T. Masamura, J. Arai, H. Matsumoto, W. Tsuji, H. Matsuda, A. Kani, Y. Ono, F. Tsuji, and N. Yoshida, Automotive Suspension. Tokyo: Kayaba Technical Publisher, 2005, 2nd ed., pp. 26–68 (in Japanese).","K. Tanifuji, \"The Development of Car Vibration Analyzing System for Maintenance of Riding Quality. 1st Report: Outline of the Vibration Analyzing System,\" Trans JSME C, 52(481), pp. 2405–2408, 1986 (in Japanese).","C. V. Suciu, and T. Tobiishi, \"Comfortableness Evaluation of an Automobile Equipped with Colloidal Suspensions,\" JSME Journal of System Design and Dynamics, 6(5), pp. 555–567, 2012.","V. Kumar, and V. H. Saran, \"A Review of the Performances of Reading Activity by Seated Subjects Exposed to Whole Body Vibration,\" International Journal of Mechanical Engineering and Robotics Research, 1(1), pp. 193–198, 2014.\n[10]\tC. H. Lewis, and M. J. Griffin, \"Prediction the Effects of Vertical Vibration Frequency, Combinations of Frequencies and Viewing Distance on the Reading of Numeric Displays,\" Journal of Sound and Vibration, 70(3), pp. 355–377, 1980.\n[11]\tJ. Sundstrom, Difficulties to Read and Write Under Lateral Vibration Exposure. Stockholm: Doctoral Thesis, Royal Institute of Technology Aeronautical and Vehicle Engineering, Rail Vehicles, 2007, pp. 56–58.\n[12]\tT. Tomioka, T. Takigami, A. Fukuyama, and T. Suzuki, \"Prevention of Carbody Vibration of Railway Vehicles Induced by Imbalanced Wheelsets with Displacement Dependent Rubber Bush,\" Journal of Mechanical Systems for Transportation and Logistics, 3, pp. 131–142, 2010.\n[13]\tT. Tomioka, and T. Takigami, \"Reduction of Bending Vibration in Railway Vehicle Carbodies using Carbody-Bogie Dynamic Interaction,\" Vehicle System Dynamics, 48, pp. 467–486, 2010.\n[14]\tB. Suciu, and T. Tomioka, \"Experimental Investigation on the Elastic and Dissipative Characteristics of a Yaw Colloidal Damper Destined to Carbody Suspension of a Bullet Train,\" Journal of Physics: Conference Series, 744(012142), pp. 1–11, 2016."]}
- Published
- 2016
- Full Text
- View/download PDF
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.