scholarly journals Modeling of anisotropic base plate of a ballastless railway track under dynamic influences

Vestnik MGSU ◽  
2020 ◽  
pp. 1105-1114
Author(s):  
Lilia A. Illarionova ◽  
Alexey A. Loktev
Keyword(s):  
Mathematical Model ◽  
Dynamic Behavior ◽  
High Speed ◽  
Vertical Component ◽  
Base Plate ◽  
Railway Track ◽  
Rolling Stock ◽  
Cylindrical Anisotropy ◽  
Concrete Plate ◽  
Shock Impact

Introduction. Due to dynamic loading, the upper structure of the railway track is subject to deformation over the entire construction and operation period. This paper focuses on the development of a mathematical model of the base plate of a general-type ballastless railway track structure without relying on specific existing technological solutions used for such elements. The effect of the actually given vertical component of the rolling stock velocity arising from the deviation from the design position of the long-welded rails on the dynamic deflection of the plate and the contact force of cylindrical anisotropy and the initial rate of dynamic interaction is studied. The proposed model makes it possible to take into account the effect of elastic waves originating in the contact area between the wheel and the rail that move at their final speeds after contact. The actual issue researched in this paper is the reinforcement of the ballastless railway base plate for the prevention of severe damage in the base plate. Materials and methods. A mathematical model has been developed to describe the dynamic behavior of a reinforced concrete plate of a ballastless railway track taking into account the specifics of load application from rolling stock wheel sets. Results. Detailed presentation of the research results in the form of analytical expressions and dependence diagrams of dynamic and kinematic parameters of the structure behavior can have practical application when designing rapid transit and high-speed railway lines both in Russia and abroad. Conclusions. The obtained results can be used for carrying out full-fledged research of dynamic behavior of the track bed under mobile loading, for checking the local durability of plates under shock impact, for researching and selecting optimal rigidity parameters for the track bed.

scholarly journals World Experience in Creating Mathematical Models of Air Springs: Advantages and Disadvantages

2021 ◽  
pp. 25-42
Author(s):  
A. Y Kuzyshyn ◽  
S. A Kostritsia ◽  
Yu. H Sobolevska ◽  
А. V Batih
Keyword(s):  
Mathematical Model ◽  
Finite Element ◽  
Mathematical Models ◽  
Dynamic Behavior ◽  
High Speed ◽  
Vertical Direction ◽  
Rolling Stock ◽  
Air Spring ◽  
Advantages And Disadvantages ◽  
Mechanical Models

Purpose. Taking into account the production and commissioning of modern high-speed rolling stock, the authors are aimed to analyze the currently created mathematical models describing the dynamic behavior of the air spring, systematize them and consider the advantages and disadvantages of each model type. Methodology. For the analysis, a comparative chronological method was used, which makes it possible to trace the development of several points of view, concepts, theories. In accordance with the adopted decision equations, the existing models of air springs were divided into three groups: mechanical, thermodynamic and finite-elements. When analyzing mathematical models, the influence of a number of parameters on the dynamic behavior of the air spring, such as disturbing force frequency, heat transfer, nonlinear characteristics of materials, the shape of the membrane, etc., was considered. Findings. A feature of mechanical models is the determination of input parameters based on the analysis of experimental results, requires access to complex measuring equipment and must be performed for each new model of an air spring separately. Unlike mechanical models, which allow taking into account the damping effect of an air spring in the horizontal and vertical direction, thermodynamic models are mainly focused on studying the dynamic behavior of an air spring in the vertical direction. The use of the finite element method makes it possible to most accurately reproduce the dynamic behavior of an air spring, however, it requires significant expenditures of time and effort to create a finite element model and perform calculations. Originality. Mathematical models of the dynamic behavior of an air spring are systematized, and the importance of their study in conjunction with a spatial mathematical model of high-speed rolling stock is emphasized. Practical value. The analysis of the mathematical models of the dynamic behavior of the air spring shows the ways of their further improvement, indicates the possibility of their use in the spatial mathematical model of the rolling stock in accordance with the tasks set. It will allow, even at the design stage of high-speed rolling stock, to evaluate its dynamic characteristic and traffic safety indicators when interacting with a railway track.

scholarly journals Deformation Law and Control Limit of CRTSIII Slab Track under Subgrade Frost Heave

2021 ◽  
Vol 11 (8) ◽  
pp. 3520
Author(s):  
Xiaopei Cai ◽  
Qian Zhang ◽  
Yanrong Zhang ◽  
Qihao Wang ◽  
Bicheng Luo ◽  
...  
Keyword(s):  
High Speed ◽  
Base Plate ◽  
Element Model ◽  
Middle Part ◽  
Railway Track ◽  
Frost Heave ◽  
Track Structure ◽  
Slab Track ◽  
Plastic Damage ◽  
Track Irregularity

In order to find out the influence of subgrade frost heave on the deformation of track structure and track irregularity of high-speed railways, a nonlinear damage finite element model for China Railway Track System III (CRTSIII) slab track subgrade was established based on the constitutive theory of concrete plastic damage. The analysis of track structure deformation under different subgrade frost heave conditions was focused on, and amplitude the limit of subgrade frost heave was put forward according to the characteristics of interlayer seams. This work is expected to provide guidance for design and construction. Subgrade frost heave was found to cause cosine-type irregularities of rails and the interlayer seams in the track structure, and the displacement in lower foundation mapping to rail surfaces increased. When frost heave occured in the middle part of the track slab, it caused the greatest amount of track irregularity, resulting in a longer and higher seam. Along with the increase in frost heave amplitude, the length of the seam increased linearly whilst its height increased nonlinearly. When the frost heave amplitude reached 35 mm, cracks appeared along the transverse direction of the upper concrete surface on the base plate due to plastic damage; consequently, the base plate started to bend, which reduced interlayer seams. Based on the critical value of track structures’ interlayer seams under different frost heave conditions, four control limits of subgrade frost heave at different levels of frost heave amplitude/wavelength were obtained.

scholarly journals Experimental settlement and dynamic behavior of a portion of ballasted railway track under high speed trains

2008 ◽  
Vol 316 (1-5) ◽  
pp. 211-233 ◽  
Author(s):  
A. Al Shaer ◽  
D. Duhamel ◽  
K. Sab ◽  
G. Foret ◽  
L. Schmitt
Keyword(s):  
Dynamic Behavior ◽  
High Speed ◽  
Railway Track ◽  
High Speed Trains

scholarly journals Determination of the maximum dangerous width of a rail track on a reinforced concrete base with fasteners of the КБ type, taking into account all influencing factors

2021 ◽  
pp. 113-120
Author(s):  
Vadym Novikov ◽  
Andriy Babenko ◽  
Oleksandr Kharkivskyi ◽  
Olena Olexandrivna Tkachenko
Keyword(s):  
Reinforced Concrete ◽  
High Speed ◽  
Railway Track ◽  
Rolling Stock ◽  
Lateral Direction ◽  
Maximum Width ◽  
Rail Track ◽  
Emergency Braking ◽  
Simultaneous Influence

Railway track retention standards in Ukraine do not take into account theconstruction of the subrail base, but regulate one for all types maximum dangerous value of the trackwidth, which was changed from 1546 mm to 1548 mm without any justification of scientific researchor explanations of the effects of tolerances the width of the rail track and the wheel track, which ingeneral at that time were not fully investigated but taking into account the emergence anddevelopment of new scientific problems associated with the emergence of intensive lateral wear ofrails and ridges of locomotive and wagon wheels. The deterministic dependences of lateralimpressions of the P65 type rail thread head on the simultaneous influence of vertical and horizontalforces for the newly installed repair profiles of UZ rolling stock on the basis of previously performedexperimental and theoretical studies were investigated. The results allow at this stage of research todetermine and calculate the practical values of the maximum dangerous width of the track, in whichthe subrail base consists of reinforced concrete sleepers and separate rail fasteners, which are usedboth on conventional highways with mixed traffic and on high-speed lines UZ.The article establishes the need to take into account new factors influencing the dangerouswidth of the rail track with intermediate rail fasteners of separate type depending on the load stress of sections and new repair profiles of rolling stock, as well as wear processes of intermediate railfasteners type KБ and its elements on the appearance of elastic backlash in the lateral direction fromthe influence of the guide wheels of the rolling stock. The recommended value of the maximum widthof the rail track for areas where service or emergency braking is applied - 1550 mm, taking intoaccount that the contact of the wheel and the rail is not at a point, but on an ellipse. The establishednorm of the maximum width of a rail track allows to define economic efficiency of introduction in theconditions of operation of a track in curved sections of a track of small radii with limited use of themaximum admissible lateral wear (15 mm) of a head of a rail thread provided that the normal-forcedentry of rolling stock carts.

Simulation of reciprocating gas compressors with automatic reed valves

SIMULATION ◽  
1967 ◽  
Vol 8 (4) ◽  
pp. 209-214 ◽  
Author(s):  
M.W. Wambsganss ◽  
Donald Coates ◽  
Raymond Cohen
Keyword(s):  
Mathematical Model ◽  
Computer Simulation ◽  
Steady State ◽  
Dynamic Behavior ◽  
High Speed ◽  
Experimental Results ◽  
The Other ◽  
Reciprocating Compressor ◽  
Trial And Error ◽  
State Tests

The simulation of high-speed reciprocating refrigeration compressors was motivated by the needs of design engi neers. In this paper a mathematical model describing the dynamic behavior of a reciprocating compressor is pre sented. The model is semianalytic in that two types of empirical factors are required to relate phenomena not yet analytically predictable. One type is obtained from steady- state tests and the other by trial and error based on com parison with experimental results. Both analog and digital computers were considered as means of simulating the model. Due to nonlinearities in the model, the digital com puter, using Fortran IV, was selected. To evaluate the sim ulation, a one-quarter horsepower 3600-rpm stock com pressor was modified and used as a laboratory vehicle. A typical correlation between the computer simulation and experimental results is given. In general, good correlation was achieved.

scholarly journals RESEARCH OF DEVELOPMENT TRENDS OF HIGH-SPEED TRAFFIC IN THE REPUBLIC OF KAZAKHSTAN

2021 ◽  
Vol 118 (3) ◽  
pp. 22-28
Author(s):  
Yermek Bitigov ◽  
Dinar Bekzhanov ◽  
Saule Bekzhanova
Keyword(s):  
High Precision ◽  
High Speed ◽  
Railway Track ◽  
Rolling Stock ◽  
High Tech ◽  
Technical Solution ◽  
Effective System ◽  
The Creation ◽  
The Republic ◽  
Design Construction

The start of work on the high-speed highway has become a real technological challenge. Since we are talking about a new high-tech railway facility, there is a need for fundamentally new engineering and technical solutions, innovative approaches to conducting surveys, designing, building and operating new rolling stock and infrastructure.High accuracy in the design, construction and maintenance of the railway track is of key importance in the creation of a high-speed highway. A thorough analysis of the experience of the world's leading organizations in China, Japan and European countries, specializing in the creation and operation of high-speed highways, shows that the most effective system-technical solution is the transition to the use of high-precision coordinate methods of design, construction and maintenance management of infrastructure and rolling stock.It is precisely the high-precision coordinate methods that open the way to the transition to the operation of the infrastructure in the design position. And this, according to the world's leading experts, is an opportunity to reduce the cost of the current maintenance of such an expensive infrastructure by 20-30%.The technical solution that ensures the use of coordinate methods in the" end-to-end " technological life cycle of infrastructure objects is the creation of a high-precision coordinate system along the directions of the high-speed highway.

Thermal and load rate-dependent interaction between embedded rail system and bridge

2018 ◽  
Vol 233 (3) ◽  
pp. 326-336 ◽  
Author(s):  
Vojtěch Stančík ◽  
Pavel Ryjáček ◽  
Miroslav Vokáč
Keyword(s):  
High Speed ◽  
Railway Track ◽  
Rolling Stock ◽  
Railway Bridges ◽  
Rate Dependent ◽  
Rail System ◽  
Interaction Behavior ◽  
Railway Infrastructure ◽  
Load Rate ◽  
Recent Developments

Recent developments in the technology of a modern embedded rail system grant many new possibilities for improving the railway infrastructure. An embedded rail system significantly reduces noise and the dynamical impact affecting both the infrastructure and the rolling stock itself. An embedded rail system may be used for constructing any type of railway infrastructure including high-speed railways. Its attributes are also suitable for modernization of the current steel railway bridges or constructing new structures, where slender bridge decks are required. However, in a railway track equipped with an embedded rail system, stress increments rise due to its restricted expansion movement. This effect is naturally higher when the embedded rail system is placed on a bridge, because of their different deformation possibilities. For a wider use of embedded rail system, examining the interaction behavior between the embedded rail system and the substructure is a matter of essential importance. Furthermore, the nonlinear character of embedded rail system polymer-based components needs to be considered when examining their interaction behavior. Therefore, this paper aims at investigating the nonlinear coupling functions of an embedded rail system under the effects of temperature and load rate. For this purpose, a comprehensive analysis consisting of laboratory experiments, material tests of the embedded rail system components and subsequent numerical validation was performed. Results are concluded in the paper.

scholarly journals Chaotic Dynamics of Cage Behavior in a High-Speed Cylindrical Roller Bearing

2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Long Chen ◽  
Xintao Xia ◽  
Haotian Zheng ◽  
Ming Qiu
Keyword(s):  
Mathematical Model ◽  
Dynamic Behavior ◽  
Chaos Theory ◽  
High Speed ◽  
Chaotic Dynamics ◽  
Roller Bearing ◽  
Hydrodynamic Behavior ◽  
Solid Foundation ◽  
Cylindrical Roller Bearing ◽  
Cylindrical Roller

This paper presents a mathematical model to investigate the nonlinear dynamic behavior of cage in high-speed cylindrical bearing. Variations of cage behavior due to varying cage eccentricity and cage guidance gap are observed. Hydrodynamic behavior in cage contacts is taken into consideration for a more realistic calculation of acting forces owing to high working speed. Analysis of real-time cage dynamic behavior on radial plane is carried out using chaos theory based on the theoretical and mathematical model established in the paper. The analytical results of this paper provide a solid foundation for designing and manufacturing of high-speed cylindrical roller bearing.

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.

Sign in / Sign up

Export Citation Format

Share Document