Influence of track irregularities on the vertical acceleration of cars during high-speed traffic

2021 ◽  
Vol 18 (3) ◽  
pp. 335-339
Author(s):  
Vladimir N. SMIRNOV ◽  
◽  
Andrey V. LANG ◽  
Nikita A. LABUTIN ◽  
◽  
...  
Keyword(s):  
Differential Equations ◽  
High Speed ◽  
Practical Importance ◽  
Rolling Stock ◽  
Vertical Acceleration ◽  
Bridge Structures ◽  
Optimal Dynamic ◽  
Rolling Load ◽  
Train System ◽  
Track Irregularities

Objective: Obtaining differential equations of the “bridge-train” system, the solution of which allows one to identify the optimal dynamic parameters of the vehicle of high-speed rolling stock and bridge structures when rolling load moves at high speed. Methods: Derivation of differential equations of the “bridge– train” system by the analytical method. Results: Obtaining formulas for determining the acceleration of the spring borne part of rolling stock vehicles depending on track irregularities. Practical importance: Based on the results of calculations according to these formulas, a reasonable assignment of the values of camber and the possibility of assessing the effect of random irregularities of the rail track on the bridge are provided.

THE IMPROVEMENT OF WHEEL TREAD REPROFILING PROCESS

2017 ◽  
pp. 120-128
Author(s):  
Igor Ivanov ◽  
Dmitriy Kononov ◽  
Sergey Urushev
Keyword(s):  
High Speed ◽  
Performance Enhancement ◽  
Practical Knowledge ◽  
Practical Importance ◽  
Rolling Stock ◽  
Speed Profile ◽  
Operating Life ◽  
Operational Life ◽  
High Speed Grinding ◽  
Process Solutions

Object: To show the lack of wheelset operating life efficiency use in case traditional methods of wheel tread reprofiling were used in the process of repair works. To consider the possibilities of further improvement of this process on the basis of new reprofiling technologies, using the deep and high-speed grinding. Methods: The methods of wheel tread reprofiling were analyzed, the effective process solutions, based on theoretical conclusions and current practical knowledge, were studied. Results: Wheel set wastage in case of using the traditional ways of reprofiling was estimated. Preliminary parameters of wheelset reprofiling modes using high-speed grinding were estimated, providing for the increase in wheel set operational life and reprofiling performance enhancement. Practical importance: The appropriateness of rolling stock wheel tread reprofiling, by using the method of infeed high-speed profile grinding, was presented. The obtained results may be applied in the development of requirements specification for wheel tread reprofiling machine at repair facilities of the Russian Railways.

The peculiarities of constructing bridges at high-speed mainline railroads

2017 ◽  
pp. 69-81
Author(s):  
Vladimir Smyrnov ◽  
Anastasia Dyayenko ◽  
Leonid Dyachenko
Keyword(s):  
High Speed ◽  
Structural Engineering ◽  
Practical Importance ◽  
Flow Diagram ◽  
Rolling Stock ◽  
High Speed Networks ◽  
Longitudinal Stiffness ◽  
Continuous Welded Rail ◽  
Train Operation ◽  
Calculation Results

Objective: To analyze calculation and construction peculiarities of bridgework at high-speed networks (VSM). Methods: Mathematical simulation, as well as numerical and analytical methods of structural engineering was applied. Results: The main peculiarities of bridge construction at high-speed networks (VSM) were analyzed in the given study. It was proved that artificial constructions at VSM operate in the conditions which differ considerably from the conditions at common railroad lines. The former include the need in continuous welded rail design along the whole length of a bridge, requirement for high stiffness of a structure; consideration of aerodynamic influence of a rolling stock, moving with high speed, on structures, consideration of “train-bridge” system’s elements interaction in order to identify resonant modes of train operation, which result in increased dynamic impact on a bridge, railway vehicles, etc. Calculation results of a “bridge- continuous welded rail” system interaction under temperature and train influence for specific types of bridgeworks multi-span beam discontinuous and continuous elevated structures were presented in the article. The influence of length, flow diagram and longitudinal stiffness of intermediate structures on force value, occurring in the rails of a rolling stock was stated. Practical importance: The description of some peculiarities of train operation at VSM bridges, which are to be considered during design engineering, were presented as well as certain measures, providing operation security and comfort of train passengers, were suggested.

scholarly journals Dynamic Analysis of a High-Speed Railway Train With the Defective Axle Bearing

2020 ◽  
Vol 25 (4) ◽  
pp. 525-531
Author(s):  
Jing Liu ◽  
Shangkun Du
Keyword(s):  
Dynamic Analysis ◽  
High Speed ◽  
Time Dependent ◽  
Force Model ◽  
High Speed Railway ◽  
The Road ◽  
Reasonable Approach ◽  
Simulation Results ◽  
Train System ◽  
Track Irregularities

Axle bearings (AXBs) are critical parts for high-speed railway trains (HSTs). Local faults in the AXBs have great influences on the operational dynamics of HSTs. Although some previous works formulated the local faults in single AXB, the vibrations of the whole train system with the defective AXB cannot be described. To overcome this problem, this study conducts a dynamic model for a HST considering a local fault in one AXB. The previous single AXB model cannot formulate the studied case. The impacts caused by the fault in the AXB is defined as a time-dependent force model considering a half-sine type. The road spectrum excitations from the roadbed and rail are formulated by a track irregularities model. The effects of the train speeds and fault sizes on the HST dynamics are introduced. The simulation results from the proposed and previous works are contrasted to show the model validation. The results show that the faults in the AXB will greatly affect the HST dynamics. It depicts that this study can afford a more reasonable approach for understanding the dynamics of HSTs considering the defective AXBs compared to the reported single AXB model.

Equivalent conicity and its influence on rolling-stock operation

2017 ◽  
pp. 247-255
Author(s):  
Artem Kyselev ◽  
Lyudmila Blazhko ◽  
Andrey Romanov
Keyword(s):  
High Speed ◽  
Practical Importance ◽  
Railway Track ◽  
Rolling Stock ◽  
Functional Dependencies ◽  
Wheel Pair ◽  
Wheel Rolling ◽  
High Speed Trains ◽  
Force Reduction ◽  
Equivalent Conicity

Objective: To identify the rolling-stock stability, force reduction, emerging in the process of wheel-rail interaction, the reduction of wheel thread and wheel flange wear, horizontal wear during high-speed running. To consider issues of wheel-rail interaction, that is the influence of a wheel pair equivalent conicity on rolling stock operation. Lateral motion of a wheel pair about an axis of a track in accordance with conicity parameters occurs in the process of standard tapered wheel-rail interaction. Methods: Calculation methods of equivalent conicity and basic assumptions in design diagram were presented. The main functional dependencies of equivalent conicity were determined. “All-purpose mechanism” bundled software, developed on the basis of FastSim algorithm introduced by G. Kalker, was applied for modeling of wheel pair operation on a railway track. Results: Interaction of VNIIZhT-RM-70 wheel for “Sapsan” high-speed trains with R65 rail type was studied, as well as UIC60 rail type used on European railroads. Wheel rolling occurs in different circumferential directions in case of lateral movement of a wheel pair Oscillating motion was described, as well as the parameters on the basis of which equivalent conicity is formed. Practical importance: The necessity in reduction of equivalent conicity to efficiency parameters of high-speed running realization on Russian railroads was revealed by means of modeling.

scholarly journals Effect of random track irregularities on selected composite bridge / track structure / high-speed train system vibrations

2013 ◽  
Vol 12 (1) ◽  
pp. 259-266
Author(s):  
Monika Podworna ◽  
Marian Klasztorny
Keyword(s):  
High Speed ◽  
Contact Stiffness ◽  
Track Structure ◽  
Computer Algorithms ◽  
High Speed Train ◽  
Approach Slabs ◽  
Composite Bridge ◽  
Random Track Irregularities ◽  
Train System ◽  
Track Irregularities

A theory of the quasi-exact physical and mathematical modelling of the composite (steel–concrete) bridge / ballasted track structure / high-speed train system (BTT) was developed, including viscoelastic suspensions of rail-vehicles on two-axle bogies, the non-linear Hertz contact stiffness and one-sided contact between the wheel sets and the rails, the viscoelastic and inertia features of the bridge, the viscoelastic track structure on and beyond the bridge, the approach slabs, and random track irregularities. Based on this theory, advanced computer algorithms for the BTT numerical modelling were written and a computer program to simulate the vertical vibrations of the BTT systems was developed. The bridge subject to the preliminary dynamic analysis and designed according to Polish standards has a 15.00 m span length. The bridge was loaded by the German ICE-3 high-speed train moving at the critical (180 and 270 km/h) and the maximum (300 km/h) operating speeds.

SPECIFIC FEATURES OF DYNAMIC INTERACTION OF MAGNETIC–LEVITATION HIGH-SPEED TRANSPORT AND BRIDGE SUPERSTRUCTURES

2018 ◽  
pp. 111-120 ◽  
Author(s):  
Georgy Igolkin ◽  
Leonid Dyachenko ◽  
Vladimir Smirnov ◽  
Pavel Pegin
Keyword(s):  
High Speed ◽  
Magnetic Levitation ◽  
Practical Importance ◽  
Dynamic Effect ◽  
Calculation Model ◽  
Similar Data ◽  
High Speed Rail ◽  
Bridge Superstructures ◽  
Bridge Structures ◽  
Bridge Superstructure

Objective: To determine key parameters for calculating dynamic effect of magnetic-levitation highspeed transport on bridge structures, carry out a dynamic analysis, and check the obtained results against experimental data and compare them with similar results on high-speed railways. Methods: In the course of the study, the method of direct integration of the dynamic problem of mo ving a mobile load along the bridge superstructure was used. Results: Computational model of a magnetic-levitation high-speed train was developed. A set of dynamic calculations was performed. Data on the magnitude of dynamic reaction of the bridge superstructure during the movement of a magnetic-levitation train were obtained. Values of the dynamic coefficient for mobile load in the speed range of up to 1000 km/h were calculated. Practical importance: Results obtained in the course of the study and the comparison made with similar data for high-speed rail transport have confirmed a significant decrease in the dynamic response of bridge superstructures when magnetic-levitation technologies are deployed. The calculation model thus developed opens up broad prospects for further research.

scholarly journals The effect of air flow on an aerodynamic device for a pantograph

2021 ◽  
Vol 2021 (4) ◽  
pp. 453-459
Author(s):  
A. A. Vorob’ev ◽  
◽  
Ya. S. Vatulin ◽  
D. D. Karimov ◽  
◽  
...  
Keyword(s):  
Energy Consumption ◽  
High Speed ◽  
Practical Importance ◽  
Aerodynamic Resistance ◽  
Rolling Stock ◽  
Current Collectors ◽  
Current Collection ◽  
Electric Rolling Stock ◽  
Air Resistance ◽  
High Speed Trains

Objective: To evaluate the infl uence of the parameters of current collectors of high-speed and very high-speed trains on the value of aerodynamic resistance. To study the effect of airfl ow on a pantograph aerodynamic device using SolidWorks software. Methods: A comparison of the obtained values of aerodynamic air resistance with those that were produced earlier is carried out. Results: By means of aerodynamic device, it is possible to reduce the speed of the air fl ow effecting the pantograph, to reduce the values of aerodynamic resistance and energy consumption, to extend the service life of current collectors. Practical importance: The proposed design can improve the current collection, which will reduce the load on the overhead line and the pantograph slide, and reduce the energy consumption of electric rolling stock.

Dynamic Response of Bridges to Moving Trains: A Study on Effects of Concrete Creep and Temperature Deformation

2012 ◽  
Vol 193-194 ◽  
pp. 1179-1182 ◽  
Author(s):  
Wen Qiu Li ◽  
Yan Zhu ◽  
Xiao Zhen Li
Keyword(s):  
High Speed ◽  
Coupled System ◽  
Dynamic Responses ◽  
Effect Of Temperature ◽  
Temperature Deformation ◽  
Vertical Acceleration ◽  
Dynamic Feature ◽  
Wheel Load ◽  
Coupling Vibration ◽  
Track Irregularities

In this paper, a great deal of research undertaken to study the dynamic responses of a high-speed railway bridge subjected to moving trains. Based on coupling vibration analysis of a rigid frame-continuous bridge, the effect on the kinetic characteristics induced by track irregularities, temperature and creep is discussed. The results show that great changes occur in parameters of trains such as rate of wheel load reduction, the vertical acceleration and the vertical Sperling index when considering the effect of temperature and creep compared with regarding track irregularities only. It is recommended that the combination of track irregularities, temperature and creep is essential to evaluate dynamic feature of train-bridge coupled system for high-speed railways.

TRANSRAPID – A High Speed Magnetically Levitated Train System

2003 ◽  
Vol 87 (4) ◽  
pp. 8-13
Author(s):  
Volker Henke ◽  
Horst Falkner
Keyword(s):  
High Speed ◽  
Magnetically Levitated ◽  
Train System

scholarly journals Droplet impact onto a spring-supported plate: analysis and simulations

2021 ◽  
Vol 128 (1) ◽  
Author(s):  
Michael J. Negus ◽  
Matthew R. Moore ◽  
James M. Oliver ◽  
Radu Cimpeanu
Keyword(s):  
High Speed ◽  
Flexible Substrate ◽  
Practical Importance ◽  
Hybrid Approach ◽  
Hydrodynamic Pressure ◽  
Analytical Framework ◽  
Canonical System ◽  
Linear Process ◽  
Plate Motion ◽  
The Impact

AbstractThe high-speed impact of a droplet onto a flexible substrate is a highly non-linear process of practical importance, which poses formidable modelling challenges in the context of fluid–structure interaction. We present two approaches aimed at investigating the canonical system of a droplet impacting onto a rigid plate supported by a spring and a dashpot: matched asymptotic expansions and direct numerical simulation (DNS). In the former, we derive a generalisation of inviscid Wagner theory to approximate the flow behaviour during the early stages of the impact. In the latter, we perform detailed DNS designed to validate the analytical framework, as well as provide insight into later times beyond the reach of the proposed analytical model. Drawing from both methods, we observe the strong influence that the mass of the plate, resistance of the dashpot, and stiffness of the spring have on the motion of the solid, which undergo forced damped oscillations. Furthermore, we examine how the plate motion affects the dynamics of the droplet, predominantly through altering its internal hydrodynamic pressure distribution. We build on the interplay between these techniques, demonstrating that a hybrid approach leads to improved model and computational development, as well as result interpretation, across multiple length and time scales.

Sign in / Sign up

Export Citation Format

Share Document