scholarly journals Influences of car body vertical flexibility on ride quality of passenger railway vehicles

2009 ◽  
Vol 223 (5) ◽  
pp. 461-471 ◽  
Author(s):  
J Zhou ◽  
R Goodall ◽  
L Ren ◽  
H Zhang
Keyword(s):  
Flexural Vibration ◽  
Ride Quality ◽  
Resonant Vibration ◽  
Structural Damping ◽  
Natural Vibrations ◽  
Vertical Stiffness ◽  
Passenger Vehicles ◽  
Railway Passenger ◽  
Geometric Filtering

To study the influences of carbody vertical stiffness on vehicle ride quality, a vertical model of railway passenger vehicles, which includes the carbody flexible effects and all vertical rigid modes, is built. With the model and the covariance method, the requirements for the carbody bending frequency are researched. The results show that when the stiffness of a carbody decreases to certain frequencies there are significant vibrations in the carbody, although structural damping provided by a fully equipped carbody will help attenuate the vibration to some extent. A simple way to avoid resonant vibration is to increase the bending frequencies of a carbody: the higher the vehicle running speed, the higher carbody stiffness could be required. However, there are practical limitations to such an increase and the method used in this study can readily obtain the lowest bending frequency required by vehicle ride quality. Finally, the geometric filtering phenomenon and its influences on the carbody resonant flexural vibration are analysed. Results show that it is this phenomenon rather than the natural vibrations of bogie bounce that most strongly influences the resonant flexural vibration of a railway carbody.

Analysis of Resonant Vibration of Railway Vehicle

2015 ◽  
Vol 752-753 ◽  
pp. 632-635
Author(s):  
Dao Gong ◽  
Wen Jing Sun
Keyword(s):  
Natural Vibration ◽  
Flexural Vibration ◽  
Railway Vehicle ◽  
Resonant Vibration ◽  
Vehicle Dynamic ◽  
Running Speed ◽  
Car Body ◽  
Fundamental Reason ◽  
Vehicle Dynamic Model ◽  
Geometric Filtering

A fully equipped railway vehicle dynamic model which considers the car body flexibility is established to analyze the fundamental reason of car body flexural resonance. Results show that it is the geometric filtering phenomenon rather than the natural vibration of bogie bounce that causes the car body resonant flexural vibration. The higher the vehicle running speed, the higher the first vertical bending frequency should be required.

scholarly journals Effect of the turning characteristics of underfloor wheel lathes on the evolution of wheel polygonisation

2018 ◽  
Vol 233 (5) ◽  
pp. 479-488 ◽  
Author(s):  
Dabin Cui ◽  
Boyang An ◽  
Paul Allen ◽  
Ruichen Wang ◽  
Ping Wang ◽  
...  
Keyword(s):  
Fourth Order ◽  
High Speed ◽  
Higher Order ◽  
Ride Quality ◽  
Sustained Use ◽  
High Speed Trains ◽  
Cut Quality ◽  
Multiple Unit ◽  
Component Failures

During both running and wheel cut operations, wheels of railway vehicles and the friction rollers that support and drive the wheelset on a typical wheel cut lathe are subject to wear and hence are likely to develop out-of-round characteristics after sustained use. The resulting out-of-round wheels can significantly affect the ride quality and can potentially increase the incidence of fatigue-related component failures due to the resulting higher intensity loading cycles. Furthermore, the corresponding out-of-round characteristics of the lathe's friction rollers will continue to degrade the subsequent cut quality of wheels. For the analysis of the out-of-round characteristics caused by an underfloor wheel lathe used for the high-speed trains in China, a mathematical model based on a typical electric multiple unit (EMU) vehicle's wheelsets and their interactions with the wheel lathe friction rollers was established. Factors influencing the cut quality of the wheels, including the number of cuts, eccentricity forms of the friction rollers and the longitudinal spacing of the two rollers, have been analysed. The results show that two cuts can effectively remove the higher order polygon on the wheel surface. The eccentricity and phase angle of the friction rollers have no influence on the cut quality of higher order polygons, whereas they are the primary cause for the fourth-order polygons. The severity of the fourth-order polygon depends on the level and the phase of the eccentricity of the friction rollers. The space of the two rollers can also significantly affect the cut quality. Obtaining the theoretical and practical value for the maintenance of polygonised wheels using the underfloor lathe is the main outcome of this study.

scholarly journals Design of Novel BELBIC Controlled Semi-Active Suspension and Comparative Analysis with Passive and PID Controlled Suspension

2021 ◽  
Vol 18 (5) ◽  
Author(s):  
Pankaj SHARMA ◽  
Vinod KUMAR
Keyword(s):  
Human Body ◽  
Degrees Of Freedom ◽  
Active Suspension ◽  
Driver Model ◽  
Ride Quality ◽  
Body Parts ◽  
Hybrid Techniques ◽  
Design Engineers ◽  
Mass Displacement

Passenger comfort, quality of ride, and handling have broughta lot of attention and concern toautomotive design engineers. These 2 parameters must have optimum balance as they have an inverse effect on each other. Researchers have proposed several approaches and techniques like PID control, fuzzy approach, GA, techniques with inspiration from nature and hybrid techniques to attain the same. A new controller based on the learning behavior of the human brain has been used for the control of semi-active suspension in this study. The controller is known as the Brain Emotional Learning-Based Intelligent Controller (BELBIC). A one-fourth model of car along with the driver model having 6 degrees of freedom (DOF) wasmodeled and simulated. The objective of the studywasto analyze the performance of the proposed controller for improving the dynamic response of the vehicle model coupled with complex biodynamic models of the human body as a passenger, making the whole dynamic system very complex to control. The performance wasanalyzed based on percentage reduction in the overshoot of the vehicle’s sprung mass as well as different human body parts when subjected to road disturbances. The proposed controller performance wascompared with the PID controller, widely used in semi-active suspension. The simulation results obtained for BELBIC controlled system for circular road bump showed that the overshoot of passenger head and body wasreduced by 18.84 and 18.82 %, respectively and reduction for buttock and leg displacement was18.87 %. The vehicle’s seat and sprung mass displacement displayedan improvement of 18.90 and 18.51 %. The overshoot of passenger's head and body displacement wasimproved by 19.79and 19.62 %,respectively, whereas improvement for buttock & leg, vehicle’s seat, and sprung mass displacement were19.81, 20.00, and 20.49 % against trapezoidal speed bump. The PID controlled suspension disclosed an improvement of 8.74, 8.53, 8.75, 11.11, 14.75 % against circular bump and 10.72, 10.33, 10.73, 11.11 and 11.75 % against trapezoidal bump for overshoot reduction of passenger head, body, buttock & leg, vehicle’s seat and sprung mass displacement, respectively. The proposed BELBIC controlled semi-active suspension outperformed the widely used PID controlled semi-active suspension and indicated asignificant improvement in the ride quality of the vehicle.

scholarly journals Assessment of vehicle brake control functional stability

2021 ◽  
Vol 12 (2) ◽  
pp. 33-44
Author(s):  
Volodymyr Volkov ◽  
◽  
Igor Gritsuk ◽  
Tetiana Volkova ◽  
Volodymyr Kuzhel ◽  
...  
Keyword(s):  
Energy Consumption ◽  
Control Method ◽  
Operating Conditions ◽  
National Standards ◽  
Passenger Vehicles ◽  
The Difference ◽  
Braking Control ◽  
The Stability ◽  
Friction Surfaces

The article is devoted to the study of the influence of the brake control elements of passenger vehicles on the stability of their braking properties. The analysis of the influence of uneven braking forces on the wheels of one axle of vehicles on the deviation of the distribution of braking forces between the axles from its calculated value is carried out. When assessing the error in regulating the distribution of braking forces between the axles of vehicles, three components were taken into account: the theoretical error due to the imperfection of the selected control method (the difference between the actual calculated control characteristic from the ideal), the error created due to the instability of the ratio of the braking forces on the front and rear wheels, an additional error caused by the unevenness of the braking forces on the wheels of individual axles, since the fulfillment of the most stringent requirements of international and national standards for the efficiency of braking of vehicles and is inextricably linked with the need to increase the energy consumption of brake mechanisms. The energy consumption of braking mechanisms is understood as the ability of the latter to dissipate the greatest amount of energy of the braking machine without reducing the braking efficiency indicators to the minimum permissible level. Excessive heating of the braking mechanisms leads to a decrease in the friction coefficient μ of the friction surfaces and increased wear of the friction linings, and the brakes are the most unstable element of the braking control, which ensures the absorption and dissipation of the vehicle's energy during braking. The instability of the braking torques on the front and rear wheels, caused by a change in the coefficients of friction of friction pairs, leads not only to a change in the distribution of braking forces between the axles and individual wheels, but also to a decrease in the braking efficiency of vehicles under operating conditions. A method is proposed that makes it possible to assess the quality of regulation of the distribution of braking forces between the axles of a car, taking into account the instability of the braking forces on the wheels.

Ride Quality of Autorack Cars

1978 ◽  
Vol 100 (2) ◽  
pp. 171-180
Author(s):  
L. P. Greenfield ◽  
L. A. McLean ◽  
E. J. Wolf
Keyword(s):  
Ride Quality

The Effect of Elevated Guideway Construction Tolerances on Vehicle Ride Quality

1975 ◽  
Vol 97 (4) ◽  
pp. 408-416 ◽  
Author(s):  
J. K. Hedrick ◽  
R. J. Ravera ◽  
J. R. Anderes
Keyword(s):  
Cross Section ◽  
Quality Criteria ◽  
Design Parameters ◽  
Ride Quality ◽  
Live Load ◽  
General Technique ◽  
Trade Off ◽  
Frequency Decomposition ◽  
Space Boundary

In this paper the ride quality of a vehicle traversing an elevated guideway is related directly to guideway construction tolerances and design parameters. Moreover, the construction tolerances are modeled in terms familiar to a guideway contractor. The tolerances modeled for an elevated, two-span semicontinuous, concrete guideway are: surface finish, camber deviations, pier survey errors, and pier settlement. The major design parameters relating to live-load deflection, stiffness (material and cross-section), and pier spacing are included. A general technique is presented for relating these tolerances to vehicle ride quality by means of a digital computer simulation. Various ride quality criteria are considered, including rms acceleration, acceleration spectral density, acceleration frequency decomposition, and a deterministic state space boundary. Numerical results are presented for a particular vehicle-guideway configuration and as such are valid only for the system considered. It is shown that for this system, equivalent ride quality can be maintained while adjusting the various construction tolerances. This trade-off capability allows the contractor to choose the least costly combination of tolerance parameters.

scholarly journals Labyrinth structure sealing performance on grounding device of railway passenger vehicles

2019 ◽  
Vol 612 ◽  
pp. 032199
Author(s):  
Gang Li ◽  
Xiangli Lin ◽  
Yingying Liu ◽  
Lun Li ◽  
Qingshan Liu ◽  
...  
Keyword(s):  
Passenger Vehicles ◽  
Sealing Performance ◽  
Railway Passenger
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