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Mechanical Engineering Commons

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2008

Civil and Environmental Engineering

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Articles 1 - 19 of 19

Full-Text Articles in Mechanical Engineering

Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov Dec 2008

Dynamic Properties Of Railway Track And Its Components : A State-Of-The-Art Review, Sakdirat Kaewunruen, Alexander Remennikov

Faculty of Engineering - Papers (Archive)

Recent findings indicate one of major causes of damages, which is attributed to the resonant behaviours, in a railway track and its components. Basically, when a railway track is excited to generalised dynamic loading, the railway track deforms and then vibrates for certain duration. Dynamic responses of the railway track and its components are the key to evaluate the structural capacity of railway track and its components. If a dynamic loading resonates the railway track’s dynamic responses, its components tend to have the significant damage from excessive dynamic stresses. For example, a rail vibration could lead to defects in ...


Development Of A Mathematical Model For 3d Reconstruction Of Target Objects By Photogrammetry, Keith F. Blonquist Dec 2008

Development Of A Mathematical Model For 3d Reconstruction Of Target Objects By Photogrammetry, Keith F. Blonquist

All Graduate Theses and Dissertations

This thesis outlines the development of a mathematical model which can be used to perform 3D reconstruction of a target object from surveillance images. 3D reconstruction is a common procedure in photogrammetry, but performing 3D reconstruction from surveillance images can be more difficult than typical photogrammetry applications.

Surveillance images are generally captured in an unsystematic manner because there is no control over the target that is being photographed. Surveillance images can have a wide variety of fields of view, are often captured with uncalibrated cameras, and typically the targets are objects for which there is no other a priori information ...


Detection Of Voids In Prestressed Concrete Bridges Using Thermal Imaging And Ground-Penetrating Radar, David G. Pollock, Kenneth J. Dupuis, Benjamin Lacour, Karl R. Olsen Dec 2008

Detection Of Voids In Prestressed Concrete Bridges Using Thermal Imaging And Ground-Penetrating Radar, David G. Pollock, Kenneth J. Dupuis, Benjamin Lacour, Karl R. Olsen

Faculty Publications - Biomedical, Mechanical, and Civil Engineering

Thermal imaging and ground-penetrating radar was conducted on concrete specimens with simulated air voids. For the thermal imaging inspections, six concrete specimens were constructed during the month of June 2007 to simulate the walls of post-tensioned box girder bridges. The objective was to detect simulated air voids within grouted post-tensioning ducts, thus locating areas where the post-tensioning steel strands are vulnerable to corrosion. The most important deduction taken from these inspections was that PT-ducts and simulated voids were more detectable in the 20 cm (8 in.) thick specimens than in the 30 cm (12 in.) thick specimens. While inspections of ...


Dynamic Responses Of Marine Risers/Pipes Transporting Fluid Subject To Top End Excitations, J. Leklong, S. Chucheepsakul, S. Kaewunruen Nov 2008

Dynamic Responses Of Marine Risers/Pipes Transporting Fluid Subject To Top End Excitations, J. Leklong, S. Chucheepsakul, S. Kaewunruen

Faculty of Engineering - Papers (Archive)

This paper deals with the dynamic responses to top end excitation of marine risers/pipes conveying internal fluid. The marine riser is often used as a flexible link between undersea bore head and subsurface offshore platform. The tidal waves and the changes of sea level consistently excite its top end connected to a floating vessel. In order to carry out the performance-based design of the marine risers, the evaluation of their dynamic responses to top end excitations is imperative. In this study, the marine riser is simulated using twodimensional beam elements. Energy functional of the marine risers conveying fluids is ...


European Climate Policy And The Position Of Cyprus, Theodoros Zachariadis Oct 2008

European Climate Policy And The Position Of Cyprus, Theodoros Zachariadis

Theodoros Zachariadis

No abstract provided.


Ole Miss Engineer 2008 Oct 2008

Ole Miss Engineer 2008

The Ole Miss Engineer

No abstract provided.


Reliability Analysis Of Plank Decks, Andrzej S. Nowak, Christopher D. Eamon Sep 2008

Reliability Analysis Of Plank Decks, Andrzej S. Nowak, Christopher D. Eamon

Civil and Environmental Engineering Faculty Research Publications

The objective of this study is to summarize the load and resistance criteria for highway bridge plank decks, and to estimate the reliability of plank decks designed by AASHTO Code. Both transverse and longitudinal planks for a variety of typical stringer spacings and plank sizes are considered. Truck traffic load data is based on the model used to calibrate the 1994 AASHTO LRFD Code. However, for plank decks, wheel load rather than whole vehicle weight is most important, and these statistics are developed for this study. For wood planks, dead load and dynamic load are not significant. The limit state ...


Development Of A Particle Flow Test For Rotational Molding, Russell B. Whatcott Jun 2008

Development Of A Particle Flow Test For Rotational Molding, Russell B. Whatcott

Theses and Dissertations

One of the current testing method (the Dry Flow test) to qualify resin for use in production in the rotomolding process has been shown to have many flaws in both equipment and procedure. Research was done here to investigate a possible alternative that could eliminate some of these testing deficiencies. By reducing equipment and operator errors, the testing of materials becomes more valuable of an exercise. The Angular Flow test developed in this research can increase repeatability. By coming to understand the rotational molding process better, an evaluation that can give more valid information was devised.


Fuel Taxation And Social Policy, Theodoros Zachariadis Jun 2008

Fuel Taxation And Social Policy, Theodoros Zachariadis

Theodoros Zachariadis

No abstract provided.


College Of Engineering Senior Design Competition Spring 2008, University Of Nevada, Las Vegas May 2008

College Of Engineering Senior Design Competition Spring 2008, University Of Nevada, Las Vegas

Senior Projects (COE)

Part of every UNLV engineering student’s academic experience, the senior design project stimulates engineering innovation and entrepreneurship. Each student in their senior year chooses, plans, designs, and prototypes a product in this required element of the curriculum. A capstone to the student’s educational career, the senior design project encourages the student to use everything learned in the engineering program to create a practical, real world solution to an engineering challenge.

The senior design competition helps to focus the senior students in increasing the quality and potential for commercial application for their design projects. Judges from local industry evaluate ...


Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara Apr 2008

Parallel Mpi/Fortran Finite Element Symmetrical/Unsymmetrical Domain Decomposition, Siroj Tungkatara

Civil & Environmental Engineering Theses & Dissertations

MPI/FORTRAN finite element analysis software based on Domain Decomposition (DD) formulas has been developed in this work. Efficient input data storage/data communication schemes, domain partitioning, fast symbolical and numerical sparse assembly, symmetrical/unsymmetrical sparse solver and robust symmetrical/unsymmetrical iterative solvers algorithms are all incorporated into the developed code. Parallel Precondition Conjugated Gradient (PCG) and Flexible Generalized Minimum Residual (FGMRES) are developed. Efficient computational techniques used in the developed code are explained. Numerical performance and the accuracy of the developed code are conducted on acoustic examples with medium to large grid sizes. The results obtained from ODU Wilbur ...


Ole Miss Engineer 2008 Apr 2008

Ole Miss Engineer 2008

The Ole Miss Engineer

No abstract provided.


Proceedings From Scientific Conference On Green Energy And It, Dr. Erik Dahlquist Mar 2008

Proceedings From Scientific Conference On Green Energy And It, Dr. Erik Dahlquist

Dr. Erik Dahlquist

This conference is part of the annual Energitinget, a national arena for energy in Sweden, with some 2500 participants. The focus with this session is to give a forum for researchers to present scientific results, and also to discuss these with other researchers. It contains papers in the area of Energy and IT as well as Green energy generally


Use Of Modeling And Simulation In Pulp And, Dr. Erik Dahlquist Jan 2008

Use Of Modeling And Simulation In Pulp And, Dr. Erik Dahlquist

Dr. Erik Dahlquist

The book is a handbook for operators and process engineers in primarily pulp and paper industry, but also other process industries about how to utilise simulation as a tool for enhanced process operations. The book has been written as part of a EU COST action on Process Simulation, with 14 countries and 50 researchers and process industry representatives involved.


The Nonlinear Dynamics Of Tapping Mode Atomic Force Microscopy With Capillary Force Interactions, Nicole N. Hashemi, H. Dankowicz, M.R. Paul Jan 2008

The Nonlinear Dynamics Of Tapping Mode Atomic Force Microscopy With Capillary Force Interactions, Nicole N. Hashemi, H. Dankowicz, M.R. Paul

Nastaran Hashemi

We study the nonlinear dynamics of a tapping mode atomic force microscope with tip-surface interactions that include attractive, repulsive, and capillary force contributions using numerical techniques tailored for hybrid or discontinuous dynamical systems that include forward-time simulation with event handling and numerical pseudo-arclength continuation. We find four branches of periodic solutions that are separated by windows of complex and irregular dynamics. The branches of periodic solutions end where the cantilever comes into grazing contact with event surfaces in state space, corresponding to the onset of capillary interactions and the onset of repulsive forces associated with contact. These windows of irregular ...


Predicting Loads On Ground Engaging Tillage Tools Using Computational Fluid Dynamics, Mark Eugene Barker Jan 2008

Predicting Loads On Ground Engaging Tillage Tools Using Computational Fluid Dynamics, Mark Eugene Barker

Retrospective Theses and Dissertations

A new method of evaluating tillage tools using computational fluid dynamics is proposed. Steady-state CFD only and transient two-way fluid-structure interaction simulations were run to predict draft and vertical forces on a spring-reset field cultivator standard. Using CFD the soil was treated as a visco-plastic fluid using the Bingham-plastic material model. Lab tests were run using a rigid flat steel bar and a production field cultivator standard with 178 and 254 mm sweeps for comparison. The results indicate that the method can be used to reasonably predict the draft force to within three standard deviations of the average measured draft ...


Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya Deodhar, Sebastian Bawab, Aravind Hanasoge Jan 2008

Development And Validation Of A Dynamic Model Of The Maglev Transportation System At Old Dominion University, Ajinkya Deodhar, Sebastian Bawab, Aravind Hanasoge

Mechanical & Aerospace Engineering Faculty Publications

A dynamic model of the vehicle/guideway coupled with a controller is developed for the maglev demonstration system currently being developed at ODU, using the MAthematical DYnamic MOdeling software - MADYMO. The fundamental characteristics of the vehicle and guideway are obtained from detailed finite element analyses using MSC-NASTRAN. As a result, the vehicle is modeled in MADYMO as a 21- degree-of-freedom spring-mass-damper system. A three span concrete guideway is modeled using 3D solid Hex8 elements. The air gap is modeled as a penetration of the magnets into the guideway. Decentralized colocated PD controllers are used for controlling the penetration of each ...


Comparison Of Roadside Crash Injury Metrics Using Event Data Recorders, Doug Gabauer, Hampton C. Gabler Jan 2008

Comparison Of Roadside Crash Injury Metrics Using Event Data Recorders, Doug Gabauer, Hampton C. Gabler

Faculty Journal Articles

The occupant impact velocity (OIV) and acceleration severity index (ASI) are competing measures of crash severity used to assess occupant injury risk in full-scale crash tests involving roadside safety hardware, e.g. guardrail. Delta-V, or the maximum change in vehicle velocity, is the traditional metric of crash severity for real world crashes. This study compares the ability of the OIV, ASI, and delta-V to discriminate between serious and non-serious occupant injury in real world frontal collisions. Vehicle kinematics data from event data recorders (EDRs) were matched with detailed occupant injury information for 180 real world crashes. Cumulative probability of injury ...


Ultrasonic Guided Wave Interpretation For Structural Health Inspections, Jill Paisley Bingham Jan 2008

Ultrasonic Guided Wave Interpretation For Structural Health Inspections, Jill Paisley Bingham

Dissertations, Theses, and Masters Projects

Structural Health Management (SHM) combines the use of onboard sensors with artificial intelligence algorithms to automatically identify and monitor structural health issues. A fully integrated approach to SHM systems demands an understanding of the sensor output relative to the structure, along with sophisticated prognostic systems that automatically draw conclusions about structural integrity issues. Ultrasonic guided wave methods allow us to examine the interaction of multimode signals within key structural components. Since they propagate relatively long distances within plate- and shell-like structures, guided waves allow inspection of greater areas with fewer sensors, making this technique attractive for a variety of applications ...