Download or read book Investigation of Form Effect on Ballast Mechanical Behavior Based on Discrete Element Modeling written by Bo Wang and published by BoD – Books on Demand. This book was released on 2019-08-27 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: As an essential component of the ballast track, the ballast layer provides functionali-ties such as drainage, load distribution, as well as strength and stability for the rail-way track. The mechanical behaviors of ballast track such as its permanent settle-ment, breakage, force propagation and void ratio are in a great extent influenced by the form distribution of ballast stones. Its reasonable design will greatly improve the mechanical behaviors, and thus prolong the maintenance cycle of ballast track, or reduce the number of ballast stones needed for construction. This dissertation focuses on proposing optimized ballast stones in the ballast aggre-gate in regard to their geometrical forms. As the first step, a ballast random form gen-erator, which is designed to generate ballast form databases with different form dis-tributions, is proposed. 15 databases are created for further usage. Afterwards, Dis-crete Element Method (DEM) based simulations are performed to investigate the mechanical behaviors of ballast aggregates. The simulation model is established based on a box test, whose result is presented firstly. Establishment and calibration process of the model are expatiated afterwards. A parameter study regarding to cru-cial modeling parameters is also performed. Using the validated parameters and the 15 generated form databases, DEM simulation models with different form distribu-tions of ballast stones in the ballast aggregate are proposed. Simulative methods to quantify the mechanical behaviors are elaborated. Based on the obtained results, the interrelation between mechanical behaviors of ballast aggregate and the form effect on mechanical behavior of the ballast aggregates are studied. The optimized ballast aggregate is proposed based on the findings stated above. The proposed optimized ballast aggregate is expected to be a reference for construc-tion of ballast track in real world. The modeling technic and the calibrated modeling parameters can be used for optimization for different railway operating programs.
Download or read book Modern Railway Track written by Coenraad Esveld and published by . This book was released on 2001 with total page 654 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to Theses with Abstracts Accepted for Higher Degrees by the Universities of Great Britain and Ireland and the Council for National Academic Awards written by and published by . This book was released on 2009 with total page 398 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Computational Granular Mechanics and Its Engineering Applications written by Shunying Ji and published by Springer. This book was released on 2020-05-08 with total page 387 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book systematically introduces readers to computational granular mechanics and its relative engineering applications. Part I describes the fundamentals, such as the generation of irregular particle shapes, contact models, macro-micro theory, DEM-FEM coupling, and solid-fluid coupling of granular materials. It also discusses the theory behind various numerical methods developed in recent years. Further, it provides the GPU-based parallel algorithm to guide the programming of DEM and examines commercial and open-source codes and software for the analysis of granular materials. Part II focuses on engineering applications, including the latest advances in sea-ice engineering, railway ballast dynamics, and lunar landers. It also presents a rational method of parameter calibration and thorough analyses of DEM simulations, which illustrate the capabilities of DEM. The computational mechanics method for granular materials can be applied widely in various engineering fields, such as rock and soil mechanics, ocean engineering and chemical process engineering.
Download or read book Track Geotechnology and Substructure Management written by Ernest Theodore Selig and published by Thomas Telford. This book was released on 1994-10-05 with total page 468 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive study provides practical advice and guidance on the important topics of rail transport and ground engineering, the use of which will result in optimum quality with the minimum maintenance effort and the most economical use of resources. The authors have synthesized all of their international knowledge and experience in this field, and produced, for the first time, a definitive guide for the design, construction, maintenance and renewal of railway track as they relate to geotechnology.
Download or read book Behaviour of Granular Materials written by Bernard Cambou and published by Springer. This book was released on 2014-05-04 with total page 403 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents a complete and comprehensive analysis of the behaviour of granular materials including the description of experimental results, the different ways to define the global behaviour from local phenomena at the particle scale, the various modellings which can be used for a D.E.M. analysis to solve practical problems and finally the analysis of strain localisation. The concepts developed in this book are applicable to many kinds of granular materials considered in civil, mechanical or chemical engineering.
Download or read book G otechnique written by and published by . This book was released on 2009 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Particulate Discrete Element Modelling written by Catherine O'Sullivan and published by CRC Press. This book was released on 2011-04-06 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first single work on DEM providing the information to get started with this powerful numerical modelling approach. Provides the basic details of the numerical method and the approaches used to interpret the results of DEM simulations. It will be of use to professionals, researchers and higher level students, with a theoretical overview of DEM as well as practical guidance.Selected Contents: 1.Introduction 2.Use of DEM in Geomechanics 3.Calculation of Contact Forces 4.Particle Motion 5.Particle Types 6.Boundary Conditions 7.Initial Geometry and Specimen Generation 8.Time Integration and Discrete Element Modelling 9.DEM Interpretation: A Continuum Perspective 10.Postprocessing: Graphical Interpretation of DEM Simulations 11.Basic Statisti
Download or read book U S Government Research Development Reports written by and published by . This book was released on 1967 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Rail Geotechnology Ballasted Track written by Buddhima Indraratna and published by CRC Press. This book was released on 2011-03-16 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ballast plays a vital role in transmitting and distributing train wheel loads to the underlying sub-ballast and subgrade. Bearing capacity of track, train speed, riding quality and passenger comfort all depend on the stability of ballast through mechanical interlocking of particles. Ballast attrition and breakage occur progressively under heavy cyc
Download or read book Rock Fracture Mechanics written by Hans-Peter Rossmanith and published by Springer Science & Business Media. This book was released on 1983-10-21 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ballast Railroad Design SMART UOW Approach written by Buddhima Indraratna and published by CRC Press. This book was released on 2018-06-27 with total page 196 pages. Available in PDF, EPUB and Kindle. Book excerpt: The rail network plays an essential role in transport infrastructure worldwide. A ballasted track is commonly used for several reasons, including economic considerations, load bearing capacity, rapid drainage and ease of maintenance. Given the ever-increasing demand for trains to carry heavier axle loads at greater speeds, traditional design and construction must undergo inevitable changes for sustainable performance. Ballast is an unbounded granular assembly that displaces when subjected to repeated train loading affecting track stability. During heavy haul operations, ballast progressively deteriorates and the infiltration of fluidized fines (mud pumping) from the underlying substructure and subgrade decreases its shear strength and also impedes drainage, while increasing track deformation and associated maintenance. Features: serves as a useful guide to assist the practitioner in new track design as well as remediating existing tracks. research discussed in this book has made considerable impact on the railway industry. resulting from collaborative research between academia and industry, incorporating sophisticated laboratory tests, computational modelling and field studies. This book presents a comprehensive procedure for the design of ballasted tracks based on a rational approach that combines extensive laboratory testing, computational modelling and field measurements conducted over the past two decades. Ballast Railroad Design: SMART-UOW Approach will not only become an imperative design aid for rail practitioners, but will also be a valuable resource for postgraduate students and researchers alike in railway engineering.
Download or read book Proceedings of the 7th International Conference on Discrete Element Methods written by Xikui Li and published by Springer. This book was released on 2016-12-01 with total page 1414 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the latest advances in Discrete Element Methods (DEM) and technology. It is the proceeding of 7th International Conference on DEM which was held at Dalian University of Technology on August 1 - 4, 2016. The subject of this book are the DEM and related computational techniques such as DDA, FEM/DEM, molecular dynamics, SPH, Meshless methods, etc., which are the main computational methods for modeling discontinua. In comparison to continua which have been already studied for a long time, the research of discontinua is relatively new, but increases dramatically in recent years and has already become an important field. This book will benefit researchers and scientists from the academic fields of physics, engineering and applied mathematics, as well as from industry and national laboratories who are interested in the DEM.
Download or read book Vehicle Track Coupled Dynamics written by Wanming Zhai and published by Springer Nature. This book was released on 2019-08-31 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book systematically presents the theory, numerical implementation, field experiments and practical engineering applications of the ‘Vehicle–Track Coupled Dynamics’. Representing a radical departure from classic vehicle system dynamics and track dynamics, the vehicle–track coupled dynamics theory considers the vehicle and track as one interactive and integrated system coupled through wheel–rail interaction. This new theory enables a more comprehensive and accurate solution to the train–track dynamic interaction problem which is a fundamental and important research topic in railway transportation system, especially for the rapidly developed high-speed and heavy-haul railways. It has been widely applied in practical railway engineering. Dr. Wanming Zhai is a Chair Professor of Railway Engineering at Southwest Jiaotong University, where he is also chairman of the Academic Committee and Director of the Train and Track Research Institute. He is a member of the Chinese Academy of Sciences and one of the leading scientists in railway system dynamics. Professor Zhai is Editor-in-Chief of both the International Journal of Rail Transportation, published by Taylor & Francis Group, and the Journal of Modern Transportation, published by Springer. In addition, he is a trustee of the International Association for Vehicle System Dynamics, Vice President of the Chinese Society of Theoretical and Applied Mechanics, and Vice President of the Chinese Society for Vibration Engineering. /div
Download or read book Paving Materials and Pavement Analysis written by American Society of Civil Engineers and published by Amer Society of Civil Engineers. This book was released on 2010 with total page 592 pages. Available in PDF, EPUB and Kindle. Book excerpt: Pavement Design And Paving Material Selection are important for efficient, cost effective, durable, and safe transportation infrastructure Paving Materials and Pavement Analysis contains 73 papers examining bound and unbound material characterization, modeling, and performance of highway and airfield pavements. The papers in this publication were presented during the GeoShanghal 2010 International Conference held in Shanghai, China, June 3-5, 2010.
Download or read book Finite Element Analysis Concepts written by J. E. Akin and published by World Scientific. This book was released on 2010 with total page 346 pages. Available in PDF, EPUB and Kindle. Book excerpt: Young engineers are often required to utilize commercial finite element software without having had a course on finite element theory. That can lead to computer-aided design errors. This book outlines the basic theory, with a minimum of mathematics, and how its phases are structured within a typical software. The importance of estimating a solution, or verifying the results, by other means is emphasized and illustrated. The book also demonstrates the common processes for utilizing the typical graphical icon interfaces in commercial codes. in particular, the book uses and covers the widely utilized SolidWorks solid modeling and simulation system to demonstrate applications in heat transfer, stress analysis, vibrations, buckling, and other fields. The book, with its detailed applications, will appeal to upper-level undergraduates as well as engineers new to industry.
Download or read book Railway Geotechnics written by Dingqing Li and published by CRC Press. This book was released on 2015-09-17 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Links Geotechnics with Railway Track Engineering and Railway Operation Good railway track and railway operations depend on good geotechnics, in several different ways and at varying levels. Railway Geotechnics covers track, track substructure, load environment, materials, mechanics, design, construction, measurements, and management. Illustrated by
