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 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.

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.

Safety against Derailment for Railway Vehicles

2014 ◽  
Vol 659 ◽  
pp. 223-230 ◽  
Author(s):  
Gabriel Popa ◽  
Ioan Sebesan ◽  
Marius Adrian Spiroiu ◽  
Claudiu Nicolae Badea
Keyword(s):  
Mathematical Model ◽  
Abrupt Change ◽  
Petroleum Products ◽  
Railway Vehicle ◽  
Dynamic Force ◽  
Angular Point ◽  
Railway Vehicles ◽  
Change Of Direction

The shock attack occurs at a railway vehicle circulation in a curve in which a discontinuous bend appears, mathematically represented by an angular point. In this point, shock angle produces an abrupt change of direction of the vehicle, respectively a dynamic shock force.The paper presents a mathematical model used to determine the dynamic force shock and its influence on vehicle guiding safety. The study was applied to the tank wagon on bogies for transportation of petroleum products, because such vehicles generally have derailed at circulation in curves in which have occurred accidentally discontinuous bends.It shows that the dynamic force may lead to an unacceptable increase of guiding force Y at leading axle of the vehicle, and therefore to overcome the (Y/Q)lim, which defines the limit of derailment, Q being the load on the attacking wheel.The conclusions indicate constructive measures to be taken to ensure the safety of the vehicle guiding at circulation in curves.

A simplified method of temperature control maximizing productivity of the batch reactor; The effect of inertia of the cooling system

1982 ◽  
Vol 47 (2) ◽  
pp. 454-464 ◽  
Author(s):  
František Jiráček ◽  
Josef Horák
Keyword(s):  
Mathematical Model ◽  
Temperature Control ◽  
Cooling System ◽  
Batch Reactor ◽  
Exothermic Reaction ◽  
Cooling Capacity ◽  
Variable Activity ◽  
Simplified Method ◽  
Opening And Closing ◽  
Time Of Operation

The effect has been studied of the inertia of the cooling system on the reliability of control of the temperature of the reaction mixture. The study has been made using a mathematical model of the batch reactor with an exothermic reaction. The temperature has been controlled by a two-level controller opening and closing the flow of the coolant. The aim of the control has been to maintain a constant value of the degree of utilization of the cooling capacity of the reactor. The instantaneous value of the degree of utilization has been assessed from the ratio of times for which the cooling system is idle to the time of operation. The reliability of control has been studied for variable activity of the catalyst.

scholarly journals Investigate Impact Force of Dam-Break Flow against Structures by Both 2D and 3D Numerical Simulations

Water ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 344
Author(s):  
Le Thi Thu Hien ◽  
Nguyen Van Chien
Keyword(s):  
Impact Force ◽  
Numerical Models ◽  
Splitting Method ◽  
Dam Break ◽  
Navier Stokes ◽  
Dynamic Force ◽  
Exact Mass ◽  
Initial Water ◽  
Dam Break Flow ◽  
2D And 3D

The aim of this paper was to investigate the ability of some 2D and 3D numerical models to simulate flood waves in the presence of an isolated building or building array in an inundated area. Firstly, the proposed 2D numerical model was based on the finite-volume method (FVM) to solve 2D shallow-water equations (2D-SWEs) on structured mesh. The flux-difference splitting method (FDS) was utilized to obtain an exact mass balance while the Roe scheme was invoked to approximate Riemann problems. Secondly, the 3D commercially available CFD software package was selected, which contained a Flow 3D model with two turbulent models: Reynolds-averaged Navier-Stokes (RANs) with a renormalized group (RNG) and a large-eddy simulation (LES). The numerical results of an impact force on an obstruction due to a dam-break flow showed that a 3D solution was much better than a 2D one. By comparing the 3D numerical force results of an impact force acting on building arrays with the existence experimental data, the influence of velocity-induced force on a dynamic force was quantified by a function of the Froude number and the water depth of the incident wave. Furthermore, we investigated the effect of the initial water stage and dam-break width on the 3D-computed results of the peak value of force intensity.

Influence of Attached Masses on Impact Forces and Running Style in Heel-Toe Running

1987 ◽  
Vol 3 (3) ◽  
pp. 264-275 ◽  
Author(s):  
Alexander Bahlsen ◽  
Benno M. Nigg
Keyword(s):  
Body Mass ◽  
High Speed ◽  
Impact Force ◽  
Force Plate ◽  
The Body ◽  
Additional Mass ◽  
Impact Forces ◽  
Running Shoes ◽  
High Speed Film ◽  
Vertical Impact

Impact forces analysis in heel-toe running is often used to examine the reduction of impact forces for different running shoes and/or running techniques. Body mass is reported to be a dominant predictor of vertical impact force peaks. However, it is not evident whether this finding is only true for the real body mass or whether it is also true for additional masses attached to the body (e.g., running with additional weight or heavy shoes). The purpose of this study was to determine the effect of additional mass on vertical impact force peaks and running style. Nineteen subjects (9 males, 10 females) with a mean mass of 74.2 kg/56.2 kg (SD = 10.0 kg and 6.0 kg) volunteered to participate in this study. Additional masses were attached to the shoe (.05 and .1 kg), the tibia (.2, .4, .6 kg), and the hip (5.9 and 10.7 kg). Force plate measurements and high-speed film data were analyzed. In this study the vertical impact force peaks, Fzi, were not affected by additional masses, the vertical active force peaks, Fza, were only affected by additional masses greater than 6 kg, and the movement was only different in the knee angle at touchdown, ϵ0, for additional masses greater than .6 kg. The results of this study did not support findings reported earlier in the literature that body mass is a dominant predictor of external vertical impact force peaks.

scholarly journals Applications of Non-Standard analysis in Topoi to Mathematical Neurosciences and Artificial Intelligence: Infons, Energons, Receptons (I)

Mathematics ◽  
2021 ◽  
Vol 9 (17) ◽  
pp. 2048
Author(s):  
Ileana Ruxandra Badea ◽  
Carmen Elena Mocanu ◽  
Florin F. Nichita ◽  
Ovidiu Păsărescu
Keyword(s):  
Mathematical Modeling ◽  
Artificial Intelligence ◽  
Mathematical Model ◽  
Set Theory ◽  
Standard Analysis ◽  
New Methods ◽  
Internal Set ◽  
Human Thinking ◽  
Global Brain ◽  
Non Standard Analysis

The purpose of this paper is to promote new methods in mathematical modeling inspired by neuroscience—that is consciousness and subconsciousness—with an eye toward artificial intelligence as parts of the global brain. As a mathematical model, we propose topoi and their non-standard enlargements as models, due to the fact that their logic corresponds well to human thinking. For this reason, we built non-standard analysis in a special class of topoi; before now, this existed only in the topos of sets (A. Robinson). Then, we arrive at the pseudo-particles from the title and to a new axiomatics denoted by Intuitionistic Internal Set Theory (IIST); a class of models for it is provided, namely, non-standard enlargements of the previous topoi. We also consider the genetic–epigenetic interplay with a mathematical introduction consisting of a study of the Yang–Baxter equations with new mathematical results.

scholarly journals Enhanced Central System of the Traversing Rod for High-Performance Rotor Spinning Machines

2017 ◽  
Vol 17 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Jan Valtera ◽  
Petr Žabka ◽  
Jaroslav Beran
Keyword(s):  
Mathematical Model ◽  
High Performance ◽  
Mechanical Energy ◽  
Optimal Number ◽  
Dynamic Force ◽  
Rectilinear Motion ◽  
Central System ◽  
Rotor Spinning ◽  
New System

Abstract The paper deals with the improvement of central traversing system on rotor spinning machines, where rectilinear motion with variable stroke is used. A new system of traversing rod with implemented set of magnetic-mechanical energy accumulators is described. Mathematical model of this system is analysed in the MSC. Software Adams/View and verified by an experimental measurement on a real-length testing rig. Analysis results prove the enhancement of devised traversing system, where the overall dynamic force is reduced considerably. At the same time, the precision of the traversing movement over the machine length is increased. This enables to increase machine operating speed while satisfying both the maximal tensile strength of the traversing rod and also output bobbin size standards. The usage of the developed mathematical model for determination of the optimal number and distribution of accumulators over the traversing rod of optional parameters is proved. The potential of the devised system for high-performance rotor spinning machines with longer traversing rod is also discussed.

scholarly journals Motion Simulation for Triangular-Shaped Autonomous Underwater Vehicle (TAUV) with Controllable Rudder

2021 ◽  
Vol 2107 (1) ◽  
pp. 012046
Author(s):  
I Y Amran ◽  
K Isa
Keyword(s):  
Mathematical Model ◽  
Autonomous Underwater Vehicle ◽  
Research Work ◽  
Underwater Vehicle ◽  
Open Loop ◽  
Vehicle Speed ◽  
Motion Simulation ◽  
Loop Control ◽  
Angular Velocities ◽  
The Mathematical Model

Abstract The dynamic model and motion simulation for a Triangular-Shaped Autonomous Underwater Vehicle (TAUV) with independently controlled rudders are described in this paper. The TAUV is designed for biofouling cleaning in aquaculture cage fishnet. It is buoyant underwater and moves by controlling two thrusters. Hence, in this research work, the authors designed a TAUV that is propelled by two thrusters and maneuvered by using an independently controllable rudder. This paper discussed the development of a mathematical model for the TAUV and its dynamic characteristics. The mathematical model was simulated by using Matlab and Simulink to analyze the TAUV’s motion based on open-loop control of different rudder angles. The position, linear and angular velocities, angle of attack, and underwater vehicle speed are all demonstrated in the findings.

scholarly journals Methodology for studying impulse disturbance from rail joints to the railway vehicle and assessment of the efficiency of the new spring suspension

2018 ◽  
Vol 239 ◽  
pp. 01032
Author(s):  
Viktor Nekhaev ◽  
Viktor Nikolaev ◽  
Evgenii Cheltygmashev
Keyword(s):  
Energy Dissipation ◽  
Comparative Assessment ◽  
Railway Track ◽  
Railway Vehicle ◽  
Vertical Acceleration ◽  
External Disturbances ◽  
Spring Suspension ◽  
Dynamic Forces ◽  
Typical Scheme ◽  
Freight Car

The methodology for studying the impulse disturbance of the railway track joints on the indicators of the dynamic qualities of the railway vehicle has been developed. The dependence of the impulse repetition factor on the energy dissipation level in the system and the speed of the vehicle is obtained. A comparative assessment of the dynamic qualities of a freight car with a typical scheme of spring suspension and a car with suspension based on the principle of compensation of external disturbances is performed. It has been established that the spring suspension of a freight car based on the principle of compensation of external disturbances delivers to it significantly better indicators of dynamic qualities in comparison with car equipped with a new three-piece truck with a typical scheme of springs. Vertical acceleration of the car’s body with a new scheme of vibration protection and dynamic forces in spring suspension is several times less than for a car with a typical three-piece truck structure.

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