Simulating the Behaviour of a Rail String Segment under Dynamic Impac

2020 ◽  
pp. 24-41
Author(s):  
E.A. Gridasova ◽  
Al.A. Loktev ◽  
L.A. Illarionova
Keyword(s):  
Wave Equations ◽  
Interaction Force ◽  
Rolling Stock ◽  
Design Parameters ◽  
Operation Modes ◽  
Force Ratio ◽  
Contact Models ◽  
Force Contact ◽  
Materials Used ◽  
Maximum Contact

The paper presents a mathematical model for behaviour of a rail string segment bound by several railway sleepers. The model makes it possible to account for prestressing due to joining rail sections into a string, for anisotropic properties of the rail-and-sleeper assembly, and effects caused by the rolling stock for various initial loading conditions. We considered eleven functions describing wheel--rail contact. These functions enable us to select the most accurate model to describe the effects that vehicles have on railway segments that may differ in design specifics, mechanical properties of materials used, operation modes, and the presence of flaws on the rail tread and wheelset tread. The wave equations used to describe the behaviour of a rail string segment can simulate the process of elastic wave propagation after wheelset contact takes place, which is considerable in the case of high vehicle velocities. The investigation conducted allowed us to plot the wheel--rail interaction force for various contact models. The functions specified make it possible to select the optimum force ratio, taking into account the following: geometrical, mechanical and design parameters of the railway segment; operation modes; and the functions sought for in terms of obtaining the desired maximum contact force, contact duration, and loading and relief times

scholarly journals Locomotive operation mode - the basis for developing the requirements for the energy storage device on railway transport

2018 ◽  
Vol 239 ◽  
pp. 01004
Author(s):  
Andrey Shatokhin ◽  
Alexandr Galkin
Keyword(s):  
Energy Storage ◽  
Direct Current ◽  
Electric Energy ◽  
Rolling Stock ◽  
Storage Device ◽  
Contact Network ◽  
Energy Storage Device ◽  
Electric Energy Storage ◽  
Operation Modes ◽  
Electric Rolling Stock

Increasing the efficiency of cargo transportation by rail is not only one of the main directions of the company JSC “Russian Railways” but also one of the main tasks of our country in order to achieve sustainable economic growth. Electric rolling stock is the largest consumer of electric energy in the company, that’s why its effective and failure-free operation is the way to solve the set tasks. The paper deals with studies related to the operation modes of a freight electric rolling stock of direct current for the purpose of determining the requirements for electric energy storage device, since it is the electric rolling stock that determines the daily schedule of electric load. The order of the analysis of experimental trips of freight electric locomotives of a direct current on the basis of cartridges of recorders of traffic parameters installed on the locomotive is determined. On the basis of the analysis of conducted trips, the main requirements for the energy storage device were obtained with a single running of electric DC rolling stock, namely the average duration of the operation modes of the electric locomotive, the maximum, minimum, and average values of voltage and current, the average value of the electric energy returned to the contact network, time of charge/discharge, and the useful energy intensity of the electric energy storage device. The studies were carried out with the support of the Russian Foundation for Basic Research for the project No 17-20-01148 ofi_m_RZD/17.

scholarly journals A reduced order computational model of a semi-active variable-stiffness foot prosthesis

2020 ◽  
Author(s):  
Michael McGeehan ◽  
Peter Adamczyk ◽  
Kieran Nichols ◽  
Michael Hahn
Keyword(s):  
Body Weight ◽  
Center Of Pressure ◽  
Reaction Force ◽  
Variable Stiffness ◽  
Performance Standard ◽  
Design Parameters ◽  
Compression Tests ◽  
Static Compression ◽  
Lumped Parameter ◽  
Contact Models

INTRODUCTION: Passive energy storage and return (ESR) feet are the current performance standard in lower limb prostheses. A recently developed semi-active variable-stiffness foot (VSF) prosthesis balances the simplicity of a passive ESR device with the adaptability of a powered design. The purpose of this study was to model and simulate the ESR properties of the VSF prosthesis. METHODS: The ESR properties of the VSF were modeled as a lumped parameter overhung beam. The overhung length is variable, allowing the model to exhibit variable ESR stiffness. Foot-ground contact was modeled using sphere-to-plane contact models. Contact parameters were optimized to represent the geometry and dynamics of the VSF and its foam base. Static compression tests and gait were simulated. Simulation outcomes were compared to corresponding experimental data. RESULTS: Stiffness of the model matched that of the physical VSF (R2: 0.98, RMSE: 1.37 N/mm). Model-predicted resultant ground reaction force (GRFR) matched well under optimized parameter conditions (R2: 0.98, RMSE: 5.3% body weight,) and unoptimized parameter conditions (R2: 0.90, mean RMSE: 13% body weight). Anterior-posterior center of pressure matched well with R2 > 0.94 and RMSE < 9.5% foot length in all conditions. CONCLUSIONS: The ESR properties of the VSF were accurately simulated under benchtop testing and dynamic gait conditions. These methods may be useful for predicting GRFR arising from gait with novel prostheses. Such data are useful to optimize prosthesis design parameters on a user-specific basis.

Investigation of Design Parameters and Failure Criteria of O-Ring Seal Structure

2005 ◽  
Author(s):  
Dianyin Hu ◽  
Rongqiao Wang ◽  
Quanbin Ren ◽  
Jie Hong
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Shear Stress ◽  
Normal Stress ◽  
Maximum Shear Stress ◽  
Design Parameters ◽  
Element Analysis ◽  
Axisymmetric Model ◽  
Sealing Performance ◽  
Maximum Contact

First, this paper established the seal structural 2D axisymmetric model of a certain Solid Rocket Booster (SRB) and calculated the deformation and stresses at ignition through a large displacement, incompressible, contact finite element analysis. The results show that the maximum contact stress appears at the contact area and the maximum shear stress at groove notch. Then, some typical parameters of the seal structure which might have the impact on the sealing performance, such as the gap breadth, initial compressibility, fillets of the groove notch and bottom, groove width, were analyzed. We can find that the gap breadth and initial compressibility do great contributions to the maximum contact normal stress, and the groove notch and bottom fillets act upon the maximum shear stress obviously. In order to verify the validity of the 2D axisymmetric model, 3D structural finite element analysis of the structure was conducted, and the results indicate that in service, the upper flange is inclined relative to the nether flange, which seems to mean that the gap breadth can not be considered as a constant during the 2D axisymmetric analysis. However further calculations say that if using the minimum gap breadth gotten in 3D analysis as its constant gap value, the above 2D axisymmetric model can rationally take the place of 3D model to analyze the sealing performance. Finally, the failure modes & criteria of the O-ring seals based on the maximum contact normal stress and shear stress were determined to ensure the reliability of this structure.

scholarly journals Simulation modelling of the rolling stock axle test-bench

2019 ◽  
Vol 123 ◽  
pp. 01032 ◽  
Author(s):  
Serhii Raksha ◽  
Pavlo Anofriev ◽  
Oleksii Kuropiatnyk
Keyword(s):  
Test Bench ◽  
Fatigue Testing ◽  
Simulation Models ◽  
Numerical Approach ◽  
Simulation Modelling ◽  
Visual Programming ◽  
Rolling Stock ◽  
Design Parameters ◽  
Behavior Simulation ◽  
Programming Tools

Wheelset axles are essential parts of railway and mine site rolling stock. For fatigue testing of axles, various test-benches are designed to implement the cyclic loads. The effectiveness of test-bench vibration analysis grows with the use of numerical approach and simulation models created with the aid of visual programming tools. The purpose of the work is to develop and assess the proposed simulation models of test-bench dynamics created with the aid of visual programming tools. Based on mathematical models, the test-bench simulation models of the lever system vibration have been developed. Simulation models are created with the aid of Simulink visual programming tools running under Matlab system. For modelling the components of Simulink, the SimMechanics and DSP System Toolbox Libraries are used. The comparative analysis of proposed models has been made. For the first time, with the aid of Simulink visual programming tools, the set of test-bench vibration simulation models has been obtained in steady-state and transient motion modes for linear task formulation. The proposed S-models allow automation and visualization of the motion dynamics study for test-bench components in order to determine their rational elastic-weight, kinematic and dynamic behavior. Simulation of vibrations was carried out using design parameters of the test-bench metal framework.

Research on Composite Materials Used for Brake Shoes Manufacture

2016 ◽  
Vol 254 ◽  
pp. 207-211 ◽  
Author(s):  
Erika Popa ◽  
Liviu Pascu ◽  
Ana Socalici ◽  
Marius Ardelean
Keyword(s):  
Composite Material ◽  
Cast Iron ◽  
Composite Materials ◽  
Carbon Fiber ◽  
Contact Zone ◽  
Laboratory Experiments ◽  
Rolling Stock ◽  
Brake Shoe ◽  
Materials Used

The paper relates laboratory experiments in order to obtain a composite material used for brake shoe manufacture. Regarding the testing materials were processed 38 samples. The percentage and composition of materials are: 15-45% novolac, 1,5-10% hexametyltetramin, 0-8% sulfur, 0-15% carbon fiber, 0-20% graphite, 0-25% aluminum, 15-28% brass and 0-40% rubber. The evolution of tribological and temperature parameters were analyzed in the contact zone tribological testing disk - split pin method. The composite material has the role to replace the classic material (cast iron) used in brake shoes composition in order to reduce the noise caused by rolling stock.

scholarly journals Recycling of Rolling Stocks

2016 ◽  
Author(s):  
Rafael Favoretto Silva ◽  
Sakdirat Kaewunruen
Keyword(s):  
End Of Life ◽  
Environmental Benefits ◽  
Rolling Stock ◽  
The Public ◽  
Sustainable Procurement ◽  
Rail Vehicles ◽  
Management Procedures ◽  
Materials Used ◽  
Almost All ◽  
Modern Rolling

This review paper highlights feasible and practicable approaches for managing end-of-life rolling stocks. It aims to promote and enable sustainable procurement policy for rolling stocks. Firstly, it demonstrates that modern rolling stocks can potentially gain the environmental benefits since almost all of their materials used in the rolling stock manufacturing can be recycled and reused. In this study, brief definition and concept of various train types are introduced and discussed, accompanied by some demonstrative illustrations. Then, component analyses, recovery rates and percent proportion of each material in various rolling stock assemblies have been evaluated. The estimation of material quantities that can potentially be recycled has been carried out using industry data sources. The suitable management procedures for end-of-life rail vehicles are then discussed, together with the life cycle of the key materials in which the recyclability criteria take into account the environmental risks and the best and safest approaches to deal with them. The aim of this study is to increase the awareness of the public, train manufacturers and rail industries on the benefits to the environments from rolling stock recycling, which could result in sustainable society and urban livings.

scholarly journals Effect of Lubrication on the Performance and Dynamic Loads of Scroll Compressors

2001 ◽  
Vol 17 (4) ◽  
pp. 201-210
Author(s):  
Jen-Jie Hsieh ◽  
Wen-Shing Lee ◽  
Wen-Fang Wu ◽  
Sih-Li Chen
Keyword(s):  
Measured Data ◽  
Dynamic Loads ◽  
Simulation Program ◽  
Design Parameters ◽  
Rotating Speed ◽  
Design Improvement ◽  
Dynamic Analyses ◽  
Oil Flow ◽  
Computer Simulation Program ◽  
Force Contact

ABSTRACTTo study the effect of lubrication on the performance and dynamic loads of scroll compressors, a theoretical model is proposed in this paper. The model includes both thermal and dynamic analyses in which the lubrication theory is emphasized in particular. A computer simulation program is written accordingly, and the effects of different design parameters including oil flow rate, injection position, injection temperature and rotating speed are investigated. The output variables such as gas force, contact force, contact moment and thermal performance of the compressor are obtained. Some of the results are compared with experimentally measured data, and good agreements are found between the simulation results and the measured data. The applicability of the simulation program is thus verified.Analytical results from running this program can provide us valuable information on the design improvement of a scroll compressor.

A study on the optimal design and the performance evaluation of electromagnetic energy harvesting device for the rolling stock application

2020 ◽  
Vol 31 (20) ◽  
pp. 2362-2377 ◽  
Author(s):  
Jaehoon Kim
Keyword(s):  
Energy Harvesting ◽  
Cantilever Beam ◽  
High Speed ◽  
Electromagnetic Energy ◽  
Rolling Stock ◽  
Design Parameters ◽  
High Speed Train ◽  
Resonant Energy ◽  
Electromagnetic Energy Harvesting ◽  
Railroad System

An electromagnetic energy harvesting device was studied based on the design parameters of an energy harvesting device for the power source of wireless sensors node on the rolling stock. The characteristics of the generated power by the energy harvesting device were tested using the laboratory equipment and a rolling stock (a high-speed train). First, a cantilever beam energy harvesting device, which allows for easy adjustment of the length according to the frequency and the power according to the cantilever beam materials, was researched. In addition, the new design for a practical resonant energy harvesting device for the railroad system was performed. To realize the performance of the practical resonant energy harvesting device, the generated power characteristics of the energy harvesting device were tested according to the moving displacement, the number of coil turns, and the initial coil displacement between the coil and magnet. The evaluation of the performance of the manufactured resonant energy harvesting device for the railroad system, which the parameters were determined based on the test results, was conducted under real driving conditions in the high-speed train, which was traveling at 300 km/h. Finally, this study analyzed whether the power generated could be applied to the wireless sensor nodes for the railroad system.

Contact Stress in a Gerotor Pump

2003 ◽  
Author(s):  
P. Javier Gamez-Montero ◽  
Esteve Codina
Keyword(s):  
Contact Stress ◽  
Measurement Techniques ◽  
Design Parameters ◽  
Prototype Model ◽  
Gear Pump ◽  
Gear Teeth ◽  
2D Simulation ◽  
Maximum Contact Stress ◽  
Gerotor Pump ◽  
Maximum Contact

The aim of the first part of this paper is to reach the optimum design parameters of a gear set when it works as part of an internal gear pump type gerotor. The performance of the gear teeth and the whole gear set are evaluated through analytical studies to obtain the maximum contact stress in gear teethe and the volumetric characteristics. Several gear sets have been examined and the results are presented. The aim of the second part of the this paper is to documents a better understanding of the performance of a crankshaft mounted gerotor pump for IC engines lubrication. Modeling, simulation and experimental work have been examined for a specific unit. A preliminary 2D simulation is carried out by using the Finite Element Method (FEX) to calculate the maximum contact stress. At the testing phase, a prototype model of the gear set provides the maximum contact stress on a pair of teeth by using photoelasticity measurement techniques. The results are exposed and discussed and possible alterations are proposed.

scholarly journals Geometry analysis and optimal design of Geneva mechanisms with curved slots

2004 ◽  
Vol 218 (4) ◽  
pp. 449-459 ◽  
Author(s):  
J-J Lee ◽  
K-F Huang
Keyword(s):  
Optimal Design ◽  
Structural Performance ◽  
Design Parameters ◽  
Performance Indices ◽  
Mathematical Expressions ◽  
Crank Angle ◽  
Conjugate Surfaces ◽  
Geometry Analysis ◽  
Maximum Contact ◽  
Roller Radius

A systematic procedure is proposed for the design of Geneva mechanisms with curved slots. Based on the theory of conjugate surfaces, mathematical expressions for the slot profile, pressure angle and cutter's location for manufacturing are presented. In addition, to evaluate the combined kinematics and structural performance of the mechanism, the maximum contact stress and degree of wear are established as the performance index. Effects of variations in various design parameters on the values of the performance indices are investigated. Using the indices as the objective function, the optimum design that takes into account the initial crank angle, offset and roller radius is performed.

Sign in / Sign up

Export Citation Format

Share Document