The Experts below are selected from a list of 35481 Experts worldwide ranked by ideXlab platform
Sakdirat Kaewunruen - One of the best experts on this subject based on the ideXlab platform.
-
Fatigue Life Assessment Method for Prestressed Concrete Sleepers
Frontiers in Built Environment, 2017Co-Authors: Ruilin You, Chayut Ngamkhanong, Rims Janeliukstis, Sakdirat KaewunruenAbstract:Concrete sleepers are one of the most important applications of a railway track system. Researchers have previously studied the impact load characteristics and ultimate load carrying capacity of a Prestressed sleeper but research on the fatigue life of Prestressed Concrete sleepers is limited. Prestressed Concrete sleeper fatigue damage is mainly due to the accumulation of defects, caused by the repeated load of wheel-rail interaction. Fatigue load, fatigue characteristics and the existing design methods of Prestressed Concrete sleeper are summarized in this paper. The commonly used fatigue assessment methods of Concrete structures are also evaluated. Based on the results of former research result, this article presents a convenient fatigue life assessment method for a Prestressed Concrete sleeper, and contrasts with the test results. The insight information gained can be used to evaluate the service performance and predict the fatigue life of the Concrete sleeper, as well providing design flexibility and broadening the design principle. The outcome of this study may also improve the rail track maintenance and inspection criteria, in order to establish an appropriate track condition monitoring network in practice.
-
Time-Dependent Topology of Railway Prestressed Concrete Sleepers
IOP Conference Series: Materials Science and Engineering, 2017Co-Authors: Chayut Ngamkhanong, Sakdirat KaewunruenAbstract:The railway sleepers are very important component of railway track structure. The sleepers can be manufactured by using timber, Concrete, steel or other engineered materials. Nowadays, Prestressed Concrete has become most commonly used type of sleepers. Prestressed Concrete sleepers have longer life-cycle and lower maintenance cost than reinforced Concrete sleepers. They are expected to withstand high dynamic loads and harsh environments. However, durability and long-term performance of Prestressed Concrete sleepers are largely dependent on creep and shrinkage responses. This study investigates the long-term behaviours of Prestressed Concrete sleepers and proposes the shortening and deflection diagrams. Comparison between design codes of Eurocode 2 and AS3600-2009 provides the insight into the time-dependent performance of Prestressed Concrete sleepers. The outcome of this paper will improve the rail maintenance and inspection criteria in order to establish appropriate sensible remote track condition monitor network in practice.
-
Impact capacity of railway Prestressed Concrete sleepers
Engineering Failure Analysis, 2009Co-Authors: Sakdirat Kaewunruen, Alexander RemennikovAbstract:Abstract Extreme loading conditions on railway tracks may include dynamic impact loads with very high magnitude but short duration. These loading conditions are caused by wheel or rail abnormalities such as flat wheels, dipped rails, etc. This type of loading is very rare and could occur once or twice in their design life span. A high-capacity drop weight impact testing machine was constructed at the University of Wollongong, in order to evaluate the ultimate capacity of Prestressed Concrete sleepers under impact loads. This paper presents the experimental investigations to evaluate failure modes, flexural toughness, and energy absorption mechanisms for railway Prestressed Concrete sleepers under static and impact loadings. Energy absorption capacity of the Prestressed Concrete sleepers was evaluated to determine the amount of energy required to fail the sleeper under impact load. Static and impact tests were carried out on the Australian-manufactured Prestressed Concrete sleepers. The residual capacity of the Prestressed Concrete sleepers after impact has also been highlighted. Also, this paper presents a simplified approach to predict ultimate moment capacity of railway Prestressed Concrete sleepers under impact loading. Modified compression field theory has been employed in the flexural resistance prediction, based on a generalized sectional analysis software, Response-2000. Effects of dynamic strain and loading rates were taken into account for predicting the impact capacity. The test results exhibit very good correlation with the predicted results by the modified compression field theory.
Dan M Frangopol - One of the best experts on this subject based on the ideXlab platform.
-
Lifetime Performance Analysis of Existing Prestressed Concrete Bridge Superstructures
Journal of Structural Engineering-asce, 2004Co-Authors: Ferhat Akgül, Dan M FrangopolAbstract:A general methodology for lifetime performance analysis of existing Prestressed Concrete girder bridges is presented. Only the superstructure components (slab and girders) are considered. The framework for the methodology is established by identifying four distinct categories: limit state equations, random variables, deterministic parameters, and constant coefficients. The limit state equations are derived by strictly adhering to the load and capacity formulas and requirements set forth in AASHTO specifications. Generality is pursued by establishing parametric limit state equations such that the formulas are applicable to any type of Prestressed Concrete bridge having similar superstructure components. For time-variant performance analysis, special emphasis is placed on the corrosion penetration modeling in Prestressed Concrete girders. The developed methodology is applied to seven existing bridges located in Colorado to obtain the lifetime performance of these Prestressed Concrete girder bridges in the b...
Herbert A. Mang - One of the best experts on this subject based on the ideXlab platform.
-
Computational plasticity of reinforced and Prestressed Concrete structures
Computational Mechanics, 1996Co-Authors: Günter Hofstetter, Herbert A. MangAbstract:This paper contains a summary of a survey of computational mechanics of reinforced and Prestressed Concrete structures. It begins with a description of some very important experimental results. Subsequently, mathematical models for the simulation of the material behavior are reviewed briefly, followed by an exemplary overview over the finite element method (FEM) for reinforced and Prestressed Concrete structures. The apparent success of constitutive models for Concrete, resting on the theory of plasticity, is based, to a great extent, on the excellent works of the late Prof. J. C. Simo, representing milestones of progress in computational plasticity. The survey is completed by two examples of numerical analyses of reinforced and Prestressed Concrete structures.
Nigel R. Hewson - One of the best experts on this subject based on the ideXlab platform.
-
Prestressed Concrete bridges
2003Co-Authors: Nigel R. HewsonAbstract:Prestressed Concrete Bridges, Second edition, is the comprehensive reference for practicing bridge engineers on the design and construction of Prestressed Concrete bridges. Offering complete coverage of the design and construction of Prestressed Concrete bridges in a single resource, this book is an essential aid for maximizing your efficiency on projects and expanding your existing knowledge. The book covers all types of deck arrangements and construction techniques – including in-situ slabs, precast beams, segmental construction, launched bridges and cable-stayed structures – and illustrates the interaction between design and construction.This publication: (1) Outlines the fundamentals of the design of Prestressed Concrete bridges, presenting the latest analysis methods and design techniques. (2) Fully updated for bridge design to Eurocodes. (3) Provides an insight into the latest construction practices and the sophisticated equipment used in bridgeworks. (4) Multiple international examples of Prestressed Concrete bridges – including projects completed since the first edition – illustrate specific design aspects and construction processes. (5) Detailed descriptions of prestressing components and systems provide a quick reference during the scheming of projects.Prestressed Concrete Bridges, Second edition, is a must-have reference for practicing bridge engineers and an essential guide for graduates looking to further their knowledge and understanding.
-
Prestressed Concrete bridges : design and construction
2003Co-Authors: Nigel R. HewsonAbstract:* Prestressed Concrete in bridge works * Prestressing components and equipment * Durability and detailing * Grouting post-tensioned tendons * Prestress design * Design of details * Concept design of Prestressed Concrete bridges * Analysis of Prestressed Concrete bridges * Slab bridges * Beams-and-slab bridges * In-situ multi-cell box girder deck * In-situ single-cell box girder bridges * Precast segmental box girder * Precast full-length box girders * Launched box girder bridges * Cable-stayed bridges * Other Prestressed Concrete bridge types * Problems and failures * Appendices
Ferhat Akgül - One of the best experts on this subject based on the ideXlab platform.
-
Lifetime Performance Analysis of Existing Prestressed Concrete Bridge Superstructures
Journal of Structural Engineering-asce, 2004Co-Authors: Ferhat Akgül, Dan M FrangopolAbstract:A general methodology for lifetime performance analysis of existing Prestressed Concrete girder bridges is presented. Only the superstructure components (slab and girders) are considered. The framework for the methodology is established by identifying four distinct categories: limit state equations, random variables, deterministic parameters, and constant coefficients. The limit state equations are derived by strictly adhering to the load and capacity formulas and requirements set forth in AASHTO specifications. Generality is pursued by establishing parametric limit state equations such that the formulas are applicable to any type of Prestressed Concrete bridge having similar superstructure components. For time-variant performance analysis, special emphasis is placed on the corrosion penetration modeling in Prestressed Concrete girders. The developed methodology is applied to seven existing bridges located in Colorado to obtain the lifetime performance of these Prestressed Concrete girder bridges in the b...
