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Detection Of Subsurface Anomalies In Fiber-Reinforced Polymer (Frp) Wrapped Timber Bridge Components Using Infrared Thermography, William Edward Steele Iii
Detection Of Subsurface Anomalies In Fiber-Reinforced Polymer (Frp) Wrapped Timber Bridge Components Using Infrared Thermography, William Edward Steele Iii
Graduate Theses, Dissertations, and Problem Reports
This thesis presents the results of an experimental study on the use of Infrared Thermography technique for detection of subsurface anomalies in fiber reinforced polymer (FRP) wrapped timber bridge components. An extensive literature review on the application of various nondestructive evaluation techniques to composite structures has also been presented.;Simulated subsurface delaminations were constructed in the laboratory in timber piles wrapped with FRP composite fabric. The delaminations varied in size, thickness, and severity. These delaminations were placed between the 1/8&inches; thick FRP wrap and timber surface. The thermal images from the delaminated specimens were compared with thermal images from undamaged specimens …
Characterization Of Stresses Induced In Doweled Joints Due To Thermal And Impact Loads, Shiva Srinivasan
Characterization Of Stresses Induced In Doweled Joints Due To Thermal And Impact Loads, Shiva Srinivasan
Graduate Theses, Dissertations, and Problem Reports
A review of literature on dowel jointed concrete pavement response reveals that the effect of uniform temperature changes was neglected based on the assumption that concrete slabs can contract freely. The triaxial state of stresses that develop at the dowel concrete interfaces due to the application of mechanical and thermal loads has not been previously characterized. In this study a detailed Three-Dimensional Finite Element (3D FE) model was used to investigate the state of contact stresses, mid slab stresses, and load transfer efficiency that develop in dowel jointed concrete pavements under the influence of combined impact and thermal loads. The …
A Bridge's Link, Stephanie Lanphier Collins
Analytical And Experimental Study Of Frp Honeycomb Sandwich Panels With Sinusoidal Core, Justin Mark Robinson
Analytical And Experimental Study Of Frp Honeycomb Sandwich Panels With Sinusoidal Core, Justin Mark Robinson
Graduate Theses, Dissertations, and Problem Reports
Fiber reinforced plastic (FRP) composite materials and structures have been increasingly used in highway bridge applications. Recent applications have demonstrated that FRP honeycomb sandwich panels with sinusoidal core can be effectively and economically used for highway bridge deck systems. In this study, analytical and experimental characterizations are presented for a FRP honeycomb panel with sinusoidal core geometry in the plane and extending vertically between face laminates. To verify the accuracy of the a closed-form solution, several honeycomb sandwich beams with sinusoidal core waves either in the longitudinal or transverse directions are tested in bending and torsion. Also, a deck panel …
Efficient Finite Element Modeling Of Wt Sections Subjected To Uniaxial Tension, Ramanand V. Nukala
Efficient Finite Element Modeling Of Wt Sections Subjected To Uniaxial Tension, Ramanand V. Nukala
Graduate Theses, Dissertations, and Problem Reports
Present design specifications for statically loaded tension members do not consider the effects of connection eccentricity as it induces bending in statically loaded members. Previous experimental tests conducted at West Virginia University [WVU] have shown that connection eccentricity induced bending effects have the potential to significantly reduce the net section rupture capacity of a section.;The present study is focused on developing finite element tools capable of capturing the peak loads and behavioral response exhibited is the previous WVU experimental tests. The main objective of the finite element analysis is not only to estimate the failure loads of the WT section …
Numerical Model For Determining The Wetting Front In A Clay Layer Of A Leaking Composite Barrier, Mustafa Eftelioglu
Numerical Model For Determining The Wetting Front In A Clay Layer Of A Leaking Composite Barrier, Mustafa Eftelioglu
Graduate Theses, Dissertations, and Problem Reports
Composite barriers for hazardous and solid waste landfills are designed to minimize hydraulic transport of the contaminant leachate of the landfill; however, the geomembrane can be damaged during construction or otherwise contain imperfections from manufacturing. It is desirable to estimate the discharge characteristics and the flow width of such a leachate should leaks in the geomembrane occur.;Numerical solutions of the flow equations for unsaturated soil barriers can provide an understanding of the movement of a leachate through a composite barrier. The purpose of this investigation was to develop a computer model that simulated two-dimensional migration of leachate beneath holes in …
Nondestructive Testing Of Reinforced And Prestressed Concrete Structures Using Acoustic Waveguides, Komwut Wissawapaisal
Nondestructive Testing Of Reinforced And Prestressed Concrete Structures Using Acoustic Waveguides, Komwut Wissawapaisal
Graduate Theses, Dissertations, and Problem Reports
The main objective of this research is to develop both passive and active nondestructive testing techniques for reinforced and prestressed concrete structures using acoustic waveguides. The first technique introduces a two-dimensional surface waveguide to enlarge the acoustic emission (AE) monitoring area of a reinforced concrete structure. A two-dimensional steel wire system is developed as an acoustic waveguide to study the AE behavior of a reinforced concrete floor slab. AE sensors are mounted to the end of the waveguides to detect AE signals, which are generated by pencil-lead breaks at various locations on concrete surface. Results show that the use of …
Green-Ampt Infiltration Model Parameter Determination Using Scs Curve Number (Cn) And Soil Texture Class, And Application To The Scs Runoff Model, Elena Viktorovna Brevnova
Green-Ampt Infiltration Model Parameter Determination Using Scs Curve Number (Cn) And Soil Texture Class, And Application To The Scs Runoff Model, Elena Viktorovna Brevnova
Graduate Theses, Dissertations, and Problem Reports
The U.S. Department of Agriculture (USDA) Soil Conservation Service Curve Number (SCS CN) method is a simple and widely popular technique of estimation of direct runoff volume for design and natural rainfall events in small watersheds. The SCS CN procedure is incorporated into such computer programs as TR-20 and TR-55. Although the method reliably predicts 24-hr runoff volume, the predicted distribution of runoff during a storm event is not realistic. This shortcoming of the SCS CN method is due to weakness in the infiltration concept of the method. Use of a physically realistic and distributed Green-Ampt infiltration model can significantly …
Exploratory Study On High-Performance Concrete For Bridge Decks In West Virginia, Wenbo Zhang
Exploratory Study On High-Performance Concrete For Bridge Decks In West Virginia, Wenbo Zhang
Graduate Theses, Dissertations, and Problem Reports
This study is intended to provide guidelines for a future global effort on the development of HPC mixes in West Virginia using several types of available aggregates. The objective of the present study is to explore the performance of two types of mixtures using fly ash and slag, respectively, and the same limestone coarse aggregate, natural sand, and constant water/cementitious ratio. For each type, three mixtures were evaluated, with one of the three being defined according to the WVDOT-DOH specifications as a reference (20% fly ash and 30% slag by weight of total cementitious material), from which we varied the …
Comparison Study Of The Savings Between A Single And A Double Step Toll Systems, Juan Arturo Kuthy-Saenger
Comparison Study Of The Savings Between A Single And A Double Step Toll Systems, Juan Arturo Kuthy-Saenger
Graduate Theses, Dissertations, and Problem Reports
Solving the problem of highway congestion requires solutions that go beyond the capacity expansion of the roadway and towards effective capacity expansion though innovative operations of facilities. One such innovation is the implementation of congestion tolls in order to set volume levels at economically optimal levels. Transportation researches, for some time, have known the potential of congestion tolls as one solution to the congestion problem, and we are now seeing several cases of facilities operating under a congestion toll. However, essentially all of these cases operate under a single toll, i.e. the toll is fixed and does not change with …
Field Observations Of The Early-Age Behavior Of Jointed Plain Concrete Pavements, Troy Haden Schell
Field Observations Of The Early-Age Behavior Of Jointed Plain Concrete Pavements, Troy Haden Schell
Graduate Theses, Dissertations, and Problem Reports
Newly constructed rigid PCC highway pavements with open graded stabilized base courses have been found to develop non-uniform, transverse saw-cut joint-crack developments and extensive slab movement behaviors, which cause unwanted premature joint failures. Phase I of this study determined the variables associated with the sporadic, large joint opening development by literature review, laboratory tests and some field collected data. The large joints were believed to develop at early-ages of the slabs curing (within the first 48 hours). The early-age stress developments were found controlled by slab temperature history, material property development and frictional resistance. Minimal recommendations for corrects to the …
Mitigation Of Water Quality And Ecosystem Impacts Of Roadway Construction Through Retrospective Engineering Analyses, Jaime Monique Sayre
Mitigation Of Water Quality And Ecosystem Impacts Of Roadway Construction Through Retrospective Engineering Analyses, Jaime Monique Sayre
Graduate Theses, Dissertations, and Problem Reports
During the construction of a segment of Appalachian Corridor H between Buckhannon and Elkins, West Virginia, mine spoils and land use features related to historic mining were disturbed. An assessment of the water quality, benthic macro invertebrates, and fish populations was conducted to ascertain the condition of the water and to assess the biological productivity of Laurel Run, a tributary of the Tygart Valley River which runs parallel to Corridor H. The water quality and biological impairments were attributed to the ineffective vegetation of the spoils pile, which permitted water infiltration and thus, served as a source of metals and …
Wood Deck Bridges-Stress Laminated Wood Panels On Steel Beams, Bryan Lin King
Wood Deck Bridges-Stress Laminated Wood Panels On Steel Beams, Bryan Lin King
Graduate Theses, Dissertations, and Problem Reports
The objective of this project was to simulate a stress laminated timber bridge deck model stiffened with wide flange steel stringers for performance monitoring. The simulation accounted for typical HS-20 repetitive loadings offered by a mechanically controlled actuator.;Based on the results incorporated in this report and additional projects accredited in the literature review, some general recommendations can be established regarding the best approach for constructing timber bridges in the future.;In general, short span prestressed timber bridges appear to be a reliable alternative in rural bridge design applications. Pure aesthetics responsive to timber construction add to the allure of this optional …
Stress Concentration Around Dowel Bars In Jointed Rigid Concrete Pavements, Mourad Youssef Riad
Stress Concentration Around Dowel Bars In Jointed Rigid Concrete Pavements, Mourad Youssef Riad
Graduate Theses, Dissertations, and Problem Reports
In this study, the magnitude and state of stresses induced around dowel bars were identified through detailed 3D Finite Element (3DFE) modeling of dowel jointed rigid pavement structures. Both straight and skewed joints were modeled using extremely fine meshing that allows accurate modeling of the friction and separation at dowel concrete interfaces. The model response was examined for the case of joint loading with an equivalent axle load of 18000 lb. It was found that significantly large tensile stresses develop in the concrete on both sides of the loaded dowel. The magnitude of the tensile stress approaches the tensile modulus …
Statistical Properties Of Maximum Likelihood Estimates For Accelerated Lifetime Data Under The Weibull Model, Mahmoud A. Yousef
Statistical Properties Of Maximum Likelihood Estimates For Accelerated Lifetime Data Under The Weibull Model, Mahmoud A. Yousef
Doctoral Dissertations
Pipe rehabilitation liners are often installed in host pipes that lie below the water table. As such, they are subjected to external hydrostatic pressure. The external pressure leads to early deformation in the liners, which could ultimately lead to its failing or buckling before its expected service lifetime is achieved. Experiments involving long term buckling behavior of liners are typically accelerated lifetime testing procedures. In an accelerated testing procedure a liner is subjected to a constant external hydrostatic pressure and observed until it fails or for a certain time, t whichever occurs first. Liners that do not fail at time …
Structural Distress Condition Modeling For Sanitary Sewers, Vani Samyuktha Kathula
Structural Distress Condition Modeling For Sanitary Sewers, Vani Samyuktha Kathula
Doctoral Dissertations
Sewers represent a very substantial and crucial part of our underground infrastructure and a high level of investment is needed to maintain them. Sewers are generally out of sight and, as long as they continued to function reasonably well, they are also out of mind—that is, until any problems such as structural, hydraulic and functional arise. The criticality of any sewer condition is a combination of the risk of failure and the consequences of it. Therefore, a systematic approach is necessary to fully understand and evaluate the conditions of this underground infrastructure. The present state of the art does not …
Boolean Functions With Important Cryptographic Properties., Subhamoy Maitra Dr.
Boolean Functions With Important Cryptographic Properties., Subhamoy Maitra Dr.
Doctoral Theses
In this thesis we concentrate on properties of cryptographically significant Boolean functions.The techniques are mainly combinstorial and provide new resulta on enumeration and construction of such functions. Initially we concentrate on a partieular subset of Boolean functions called the symmetric Boolean functions. A closed form expression for the Walsh transform of an arbitrary symmetric Boolean function is presented. We completely characterize the symmetric functions with maximum nonlinearity and show that the maximum nonlinearity of n-variable symmetrie function can be 2n-1-2[n-1l2], Moreover, new classes of symmetric balanced and symmetric correlation immune functions are considered.We provide a randomised heuristic to construct balanced …