scholarly journals A MATHEMATICAL MODEL AND SIMULATION RESULTS OF THE DYNAMIC SYSTEM RAILWAY VEHICLE WHEEL–TRACK WITH A WHEEL FLAT / DINAMINĖS SISTEMOS „GELEŽINKELIŲ VAGONO RATAS – KELIAS“ SU RATO IŠČIUOŽA MATEMATINIS MODELIS IR MODELIAVIMO REZULTATAI

2014 ◽  
Vol 6 (5) ◽  
pp. 531-537 ◽  
Author(s):  
Rasa Žygienė ◽  
Marijonas Bogdevičius ◽  
Laima Dabulevičienė
Keyword(s):  
Mathematical Model ◽  
Dynamic System ◽  
Vertical Plane ◽  
Railway Vehicle ◽  
Discrete Elements ◽  
Model And Simulation ◽  
Research Findings ◽  
Wheel Flat ◽  
Nonlinear Elastic ◽  
Wheel Track

A mathematical model of the system Railway Vehicle Wheel–Track with a wheel flat of a wheelset has been made. The system Railway Vehicle Wheel–Track has been examined on the vertical plane. The mathematical model of the system Railway Vehicle Wheel–Track has employed linear, nonlinear, elastic and damping discrete elements. Rail dynamics haves been described using the finite element method. The unevenness of the rail and the wheel of the wheelset have been evaluated considering the contact between the rail and the wheel flat of the wheelset. The analysis of dynamic processes taking place in a railway vehicle wheel with the wheel flat moving at speed V = 60 km/h has been accomplished. The results of mathematical modelling of the above introduced dynamic system have been presented along with graphically displayed research findings of the conducted research. Sukurtas sistemos „Geležinkelių vagono ratas – kelias“ su aširačio rato iščiuoža matematinis modelis. Sistema „Geležinkelių vagono ratas – kelias“ nagrinėjama vertikalioje plokštumoje. Sistemos „Geležinkelių vagono ratas – kelias“ matematiniame modelyje yra panaudoti tiesiniai ir netiesiniai tamprieji ir slopinimo diskretiniai elementai. Bėgio dinamika aprašoma baigtinių elementų metodu. Kontakte tarp bėgio ir aširačio rato su iščiuoža įvertinti bėgio ir aširačio rato nelygumai. Atlikta geležinkelio vagono rato su iščiuoža, judančio greičiu V = 60 km/val., dinaminių procesų analizė. Pateikti šios dinaminės sistemos matematinio modeliavimo rezultatai. Tyrimų rezultatai pavaizduoti grafiškai ir pateiktos tyrimų išvados.

scholarly journals THE DYNAMIC BEHAVIOUR OF A WHEEL FLAT OF A RAILWAY VEHICLE AND RAIL IRREGULARITIES

Transport ◽  
2015 ◽  
Vol 30 (2) ◽  
pp. 217-232 ◽  
Author(s):  
Marijonas Bogdevičius ◽  
Rasa Žygienė ◽  
Stasys Dailydka ◽  
Vilius Bartulis ◽  
Viktor Skrickij ◽  
...  
Keyword(s):  
Vertical Plane ◽  
Physical And Mechanical Properties ◽  
Railway Track ◽  
Railway Vehicle ◽  
The Finite Element Method ◽  
Discrete Elements ◽  
Mathematical Experiment ◽  
Rail Irregularities ◽  
Wheel Flat ◽  
Wheel Track

The article examines a mathematical model for the system ‘Railway Vehicle Wheel–Track’ that allows examining the interaction between a wheel flat and a rail in the vertical plane. The dynamics of the railway track is described using the finite element method while that of the soil and vehicle is expressed applying discrete elements. The model is used for assessing physical and mechanical properties, the roughness of the wheel, rail surface and their geometry. The analysis of the dynamic system ‘Railway Vehicle Wheel–Track’ has been conducted. In accordance with the revised method, forces arising from contact between the wheel flat and the rail are possible to be determined in a more precise way. The article presents and analyses the results of a mathematical experiment on this system.

scholarly journals Effect of Rail Vehicle–Track Coupled Dynamics on Fatigue Failure of Coil Spring in a Suspension System

2021 ◽  
Vol 11 (6) ◽  
pp. 2650
Author(s):  
Sunil Kumar Sharma ◽  
Rakesh Chandmal Sharma ◽  
Jaesun Lee
Keyword(s):  
Mathematical Model ◽  
Fatigue Fracture ◽  
Suspension System ◽  
Railway Vehicle ◽  
Coil Spring ◽  
Internal Resonances ◽  
Rail Vehicle ◽  
Rail Vehicles ◽  
Stress Result ◽  
Wheel Track

In a rail vehicle, fatigue fracture causes a significant number of failures in the coil spring of the suspension system. In this work, the origin of these failures is examined by studying the rail wheel–track interaction, the modal analysis of the coil springs and the stresses induced during operation. The spring is tested experimentally, and a mathematical model is developed to show its force vs. displacement characteristics. A vertical 10-degree-of-freedom (DOF) mathematical model of a full-scale railway vehicle is developed, showing the motions of the car body, bogies and wheelsets, which are then combined with a track. The springs show internal resonances at nearly 50–60 Hz, where significant stresses are induced in them. From the stress result, the weakest position in the innerspring is identified and a few guidelines are proposed for the reduction of vibration and stress in rail vehicles.

Employment of Two New Methods for the Research of Interaction of Wheel with a Flat and Rail

2017 ◽  
Vol 260 ◽  
pp. 289-294 ◽  
Author(s):  
Marijonas Bogdevicius ◽  
Rasa Zygiene ◽  
Rimantas Subacius
Keyword(s):  
Mathematical Model ◽  
Impact Force ◽  
Railway Vehicle ◽  
Dynamic Force ◽  
Vehicle Speed ◽  
New Methods ◽  
Dynamic Forces ◽  
Simplified Method ◽  
Vertical Impact ◽  
Wheel Track

Dynamic force that strains on the rail and the wheel occurs. In case of wheel flats, during wheel and rail interaction, exposure time of dynamic forces acting in contact is very short and depends on the railway vehicle speed and the length of flat.Results obtained from a method that uses mathematical model of a system “Railway Vehicle Wheel-Track” and the simplified method to determine a vertical impact force of wheel with flat and rail interaction are presented in this article.The results of the mathematical and physical results of this system are analysed and presented.

scholarly journals Set-membership identifiability of nonlinear models and related parameter estimation properties

2016 ◽  
Vol 26 (4) ◽  
pp. 803-813 ◽  
Author(s):  
Carine Jauberthie ◽  
Louise Travé-MassuyèEs ◽  
Nathalie Verdière
Keyword(s):  
Mathematical Model ◽  
Parameter Estimation ◽  
Dynamic System ◽  
Nonlinear Models ◽  
Differential Algebra ◽  
Related Parameter ◽  
Set Membership ◽  
Estimation Problems ◽  
The Mathematical Model

Abstract Identifiability guarantees that the mathematical model of a dynamic system is well defined in the sense that it maps unambiguously its parameters to the output trajectories. This paper casts identifiability in a set-membership (SM) framework and relates recently introduced properties, namely, SM-identifiability, μ-SM-identifiability, and ε-SM-identifiability, to the properties of parameter estimation problems. Soundness and ε-consistency are proposed to characterize these problems and the solution returned by the algorithm used to solve them. This paper also contributes by carefully motivating and comparing SM-identifiability, μ-SM-identifiability and ε-SM-identifiability with related properties found in the literature, and by providing a method based on differential algebra to check these properties.

scholarly journals OFDM signal with BPSK modulated subcarriers for multi-carrier ionospheric sounding

2019 ◽  
Vol 30 ◽  
pp. 15006
Author(s):  
Vladimir Ivanov ◽  
Natalya Ryabova ◽  
Alexey Elsukov ◽  
Alexey Laschevsky
Keyword(s):  
Mathematical Model ◽  
Simulation Modeling ◽  
Wide Band ◽  
Ofdm Signal ◽  
Research Findings ◽  
Ionospheric Sounding ◽  
Bpsk Modulation

Paper presents the developed algorithm for multi-carrier simultaneous vertical ionospheric sounding by OFDM signal with BPSK modulation of subcarriers. There is presented a mathematical model, numerical and simulation modeling with the use of USRP platform. Research findings proved the fundamental feasibility of using orthogonal subcarriers for simultaneous sounding of channels over a wide band.

scholarly journals MATHEMATICAL MODEL OF THE WORKING PROCESS OF THE TRACK SWEEPING MACHINE AS A COMPLEX DYNAMIC SYSTEM

2019 ◽  
Vol 7 (1) ◽  
pp. 111-116
Author(s):  
M. S. Korytov ◽  
◽  
V. S. Shcherbakov ◽  
V. V. Titenko ◽  
S. D. Ignatov ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Dynamic System ◽  
Working Process ◽  
Complex Dynamic ◽  
Complex Dynamic System

EXPERIMENTAL RESEARCH ON COMPRESSION FOAM COOLING DURING ITS DELIVERY AT DIFFERENT AMBIENT TEMPERATURE MODES

2021 ◽  
Vol 4 ◽  
pp. 40-44
Author(s):  
Gumirov A. ◽  
Keyword(s):  
Experimental Data ◽  
Mathematical Model ◽  
Low Temperatures ◽  
Empirical Method ◽  
Research Application ◽  
Mass Consumption ◽  
Operating Modes ◽  
Research Findings ◽  
Conducting Research ◽  
The Impact

Purpose. The article describes methodology for conducting research on parameters of compression foam cooling during its delivery through hose-pump systems depending on the operating modes of the foam generating installation. The impact of mass consumption of compression foam on its cooling at low temperatures has been examined. The application of a mathematical model of air-foam mixture movement in hose-pump systems at different temperature modes has been substantiated. Methods. Empirical method-experiment has been used for research. Findings. A number of experiments have been carried out to confirm the developed model of compression foam moving in hose-pump systems at different temperature modes. A mobile installation for generating and delivering compression foam has been used as the object of the research. Inaccuracy in calculations obtained with the help of a mathematical model in comparison with the experimental data is 10% which makes a possible to claim that the model of compression foam moving in hose-pump systems at different temperature modes has been chosen properly. Research application field. According to the obtained data, it is possible to plan means and forces of fire units for extinguishing fires using compression foam at low temperatures. Conclusions. The developed mathematical model of compression foam movement during its delivery through hose-pump systems is confirmed by experimental data. The dependence of mass consumption impact on compression foam cooling when it is delivered through fire hoses at low temperatures has been obtained experimentally.

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