Application of Computer Simulation Methods for Running Safety Assessment of Railway Vehicles in Example of Freight Cars

2007 ◽  
Vol 9 ◽  
pp. 61-69 ◽  
Author(s):  
Andrzej Chudzikiewicz ◽  
Michał Opala
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Safety Assessment ◽  
Load Level ◽  
Simulation Methods ◽  
Railway Vehicles ◽  
Safety Issues ◽  
Rail Vehicle ◽  
Codes Of Practice ◽  
Track Irregularities

We shall discuss the problem of rail vehicle safety studies using simulation methods. The contemporary methods and criteria used for safety assessment of railway vehicles by railways Europe are shown, whereas special attention is paid to the criteria and research programs applied to the vehicle approval procedures in Poland. Taking advantage of these safety criteria and codes of practice, a number of computer simulations have been conducted in order to study the safety issues. Presented results of the computer simulations include a rail vehicle running on a tangent and curved track for different simulation parameters such as: running velocity, load level, condition of wheel profiles, track irregularities. The track irregularities represent different maintenance quality levels which are set according to UIC518 code. In this paper there has also been made a comparison between the results of computer simulation safety assessment studies and the measurements taken in real conditions during the safety tests of a Shimmns(s) type freight vehicle.

The Philosophical Novelty of Computer Simulation Methods

2019 ◽  
pp. 34-47
Author(s):  
Paul Humphreys
Keyword(s):  
Computer Simulation ◽  
Philosophy Of Science ◽  
Computer Simulations ◽  
Computational Methods ◽  
Computational Science ◽  
Simulation Methods ◽  
Scientific Methods ◽  
Analytic Methods ◽  
Epistemic Opacity

Reasons are given to justify the claim that computer simulations and computational science constitute a distinctively new set of scientific methods as compared to traditional analytic methods and that these computational methods introduce new issues in the philosophy of science. These issues are both epistemological and methodological in kind. Definitions of epistemic opacity and essential epistemic opacity are given, the syntactic and semantic accounts of theories are shown to address different problems than those addressed by computational science, the important role of concrete dynamics in simulations is stressed, and differences between in principle approaches and in practice approaches to philosophy of science are explored.

Computer Simulations of Dislocations

2006 ◽  
Author(s):  
Vasily Bulatov ◽  
Wei Cai
Keyword(s):  
Case Studies ◽  
Time Scales ◽  
Computer Simulations ◽  
Common Ground ◽  
Practical Knowledge ◽  
Simulation Methods ◽  
Computational Approaches ◽  
Learn By Doing ◽  
Data Files ◽  
Computational Materials

This book presents a broad collection of models and computational methods - from atomistic to continuum - applied to crystal dislocations. Its purpose is to help students and researchers in computational materials sciences to acquire practical knowledge of relevant simulation methods. Because their behavior spans multiple length and time scales, crystal dislocations present a common ground for an in-depth discussion of a variety of computational approaches, including their relative strengths, weaknesses and inter-connections. The details of the covered methods are presented in the form of "numerical recipes" and illustrated by case studies. A suite of simulation codes and data files is made available on the book's website to help the reader "to learn-by-doing" through solving the exercise problems offered in the book.

A Computer Simulation Approach for Engineering Air-Jet Spun Yarns

1997 ◽  
Vol 67 (3) ◽  
pp. 223-230 ◽  
Author(s):  
Rangaswamy Rajamanickam ◽  
Steven M. Hansen ◽  
Sundaresan Jayaraman
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Fiber Length ◽  
Experimental Investigations ◽  
Simulation Approach ◽  
Air Jet ◽  
Fiber Fineness ◽  
Spun Yarns ◽  
Yarn Count ◽  
Wrap Angle

A computer simulation approach for engineering air-jet spun yarns is proposed, and the advantages of computer simulations over experimental investigations and stand-alone mathematical models are discussed. Interactions of the following factors in air-jet spun yarns are analyzed using computer simulations: yarn count and fiber fineness, fiber tenacity and fiber friction, fiber length and fiber friction, and number of wrapper fibers and wrap angle. Based on the results of these simulations, yarn engineering approaches to optimize strength are suggested.

Computer Simulation of an Synthetic Ultraviolet Absorbent in the Interface of DMB and DMF

2010 ◽  
Vol 146-147 ◽  
pp. 966-971
Author(s):  
Qi Hua Jiang ◽  
Hai Dong Zhang ◽  
Bin Xiang ◽  
Hai Yun He ◽  
Ping Deng
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Density Functional ◽  
Density Functional Method ◽  
Mean Field ◽  
Functional Method ◽  
Dynamic Density ◽  
Interface Phase ◽  
Simulation Results

This work studies the aggregation of an synthetic ultraviolet absorbent, named 2-hydroxy-4-perfluoroheptanoate-benzophenone (HPFHBP), in the interface between two solvents which can not completely dissolve each other. The aggregation is studied by computer simulations based on a dynamic density functional method and mean-field interactions, which are implemented in the MesoDyn module and Blend module of Material Studios. The simulation results show that the synthetic ultraviolet absorbent diffuse to the interface phase and the concentration in the interface phase is greater than it in the solvents phase.

scholarly journals Transformation of Gear Inter-Teeth Forces into Acceleration and Velocity

1999 ◽  
Vol 5 (3) ◽  
pp. 203-218 ◽  
Author(s):  
Walter Bartelmus
Keyword(s):  
Computer Simulation ◽  
Mathematical Modelling ◽  
Computer Simulations ◽  
Production Technology ◽  
Vibration Acceleration ◽  
Acceleration Signal ◽  
Field Practice ◽  
Design Production ◽  
Extended Interpretation

The paper deals with mathematical modelling and computer simulation of a gearbox system. Results of computer simulation show new possibilities of extended interpretation of a diagnostic acceleration signal if signal is obtained by synchronous summation. Four groups of factors: design, production technology, operation, change of gear condition are discussed. Results of computer simulations give the relation between inter-teeth forces and vibration (acceleration, velocity). Some results of computer simulations are referred to the results obtained in rig measurements and in field practice. The paper shows a way of increasing the expert's knowledge on the diagnostic signal, which is generated by a gearbox system, on a base of mathematical modelling and computer simulation.

Computer Simulation Studies of Fracture in Vitreous Silica

2002 ◽  
Vol 731 ◽  
Author(s):  
Romulo Ochoa ◽  
Michael Arief ◽  
Joseph H. Simmons
Keyword(s):  
Molecular Dynamics ◽  
Computer Simulation ◽  
Computer Simulations ◽  
Silica Glass ◽  
Vitreous Silica ◽  
Uniaxial Strain ◽  
Force Function ◽  
Simulation Studies ◽  
Previous Fracture ◽  
Computer Simulation Studies

AbstractWe conduct molecular dynamics computer simulations of fracture in silica glass using the van Beest, Kramer, and van Santen model. Stress is applied by uniaxial strain at different pulling rates. Comparisons with previous fracture simulations of silica that used the Soules force function are presented. We find that in both models stress is relieved by rotation of the (SiO4)-2 tetrahedrons, increasing Si-O-Si bonding angles, and only small changes in the tetrahedron dimensions and O-Si-O angles.

scholarly journals Computer simulation methods of redundant measurements with the nonlinear transformation function

2019 ◽  
Vol 2 (5 (98)) ◽  
pp. 16-22
Author(s):  
Volodymyr Shcherban ◽  
Ganna Korogod ◽  
Vitaliy Chaban ◽  
Oksana Kolysko ◽  
Yury Shcherban’ ◽  
...  
Keyword(s):  
Computer Simulation ◽  
Transformation Function ◽  
Nonlinear Transformation ◽  
Simulation Methods

scholarly journals Quaternary regenerative CMOS logic circuits with high-impedance output state

2005 ◽  
Vol 18 (3) ◽  
pp. 505-514
Author(s):  
Dusanka Bundalo ◽  
Branimir Ðordjevic ◽  
Zlatko Bundalo
Keyword(s):  
Computer Simulation ◽  
Computer Simulations ◽  
Delay Time ◽  
Propagation Delay ◽  
Logic Circuits ◽  
Output State ◽  
High Impedance ◽  
Multiple Valued Logic ◽  
Propagation Delay Time ◽  
Simulation Results

Principles and possibilities of synthesis and design of quaternary multiple valued regenerative CMOS logic circuits with high-impedance output state are de- scribed and proposed in the paper. Two principles of synthesis and implementation of CMOS regenerative quaternary multiple-valued logic circuits with high-impedance output state are proposed and described: the simple circuits with smaller number of transistors, and the buffer/driver circuits with decreased propagation delay time. The schemes of such logic circuits are given and analyzed by computer simulations. Some of computer simulation results confirming descriptions and conclusions are also given in the paper.

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